diff options
author | Dan Magenheimer <dan.magenheimer@oracle.com> | 2012-09-05 20:44:59 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-09-06 00:04:07 (GMT) |
commit | c857ce1659b058c087bce9874cb4eeb5adbf04c5 (patch) | |
tree | 5004bcc37e5e34ca78191a55684d738031cca341 /drivers/staging/ramster/zcache-main.c | |
parent | 3ddd31fa34485ccbe358432a632bec148be18127 (diff) | |
download | linux-fsl-qoriq-c857ce1659b058c087bce9874cb4eeb5adbf04c5.tar.xz |
staging: ramster: remove old driver to prep for new base
[V2: rebased to apply to 20120905 staging-next, no other changes]
To prep for moving the ramster codebase on top of the new
redesigned zcache2 codebase, we remove ramster (as well
as its contained diverged v1.1 version of zcache) entirely.
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/ramster/zcache-main.c')
-rw-r--r-- | drivers/staging/ramster/zcache-main.c | 3320 |
1 files changed, 0 insertions, 3320 deletions
diff --git a/drivers/staging/ramster/zcache-main.c b/drivers/staging/ramster/zcache-main.c deleted file mode 100644 index d46764b..0000000 --- a/drivers/staging/ramster/zcache-main.c +++ /dev/null @@ -1,3320 +0,0 @@ -/* - * zcache.c - * - * Copyright (c) 2010-2012, Dan Magenheimer, Oracle Corp. - * Copyright (c) 2010,2011, Nitin Gupta - * - * Zcache provides an in-kernel "host implementation" for transcendent memory - * and, thus indirectly, for cleancache and frontswap. Zcache includes two - * page-accessible memory [1] interfaces, both utilizing lzo1x compression: - * 1) "compression buddies" ("zbud") is used for ephemeral pages - * 2) xvmalloc is used for persistent pages. - * Xvmalloc (based on the TLSF allocator) has very low fragmentation - * so maximizes space efficiency, while zbud allows pairs (and potentially, - * in the future, more than a pair of) compressed pages to be closely linked - * so that reclaiming can be done via the kernel's physical-page-oriented - * "shrinker" interface. - * - * [1] For a definition of page-accessible memory (aka PAM), see: - * http://marc.info/?l=linux-mm&m=127811271605009 - * RAMSTER TODO: - * - handle remotifying of buddied pages (see zbud_remotify_zbpg) - * - kernel boot params: nocleancache/nofrontswap don't always work?!? - */ - -#include <linux/module.h> -#include <linux/cpu.h> -#include <linux/highmem.h> -#include <linux/list.h> -#include <linux/lzo.h> -#include <linux/slab.h> -#include <linux/spinlock.h> -#include <linux/types.h> -#include <linux/atomic.h> -#include <linux/math64.h> -#include "tmem.h" -#include "zcache.h" -#include "ramster.h" -#include "cluster/tcp.h" - -#include "xvmalloc.h" /* temporary until change to zsmalloc */ - -#define RAMSTER_TESTING - -#if (!defined(CONFIG_CLEANCACHE) && !defined(CONFIG_FRONTSWAP)) -#error "ramster is useless without CONFIG_CLEANCACHE or CONFIG_FRONTSWAP" -#endif -#ifdef CONFIG_CLEANCACHE -#include <linux/cleancache.h> -#endif -#ifdef CONFIG_FRONTSWAP -#include <linux/frontswap.h> -#endif - -enum ramster_remotify_op { - RAMSTER_REMOTIFY_EPH_PUT, - RAMSTER_REMOTIFY_PERS_PUT, - RAMSTER_REMOTIFY_FLUSH_PAGE, - RAMSTER_REMOTIFY_FLUSH_OBJ, - RAMSTER_INTRANSIT_PERS -}; - -struct ramster_remotify_hdr { - enum ramster_remotify_op op; - struct list_head list; -}; - -#define ZBH_SENTINEL 0x43214321 -#define ZBPG_SENTINEL 0xdeadbeef - -#define ZBUD_MAX_BUDS 2 - -struct zbud_hdr { - struct ramster_remotify_hdr rem_op; - uint16_t client_id; - uint16_t pool_id; - struct tmem_oid oid; - uint32_t index; - uint16_t size; /* compressed size in bytes, zero means unused */ - DECL_SENTINEL -}; - -#define ZVH_SENTINEL 0x43214321 -static const int zv_max_page_size = (PAGE_SIZE / 8) * 7; - -struct zv_hdr { - struct ramster_remotify_hdr rem_op; - uint16_t client_id; - uint16_t pool_id; - struct tmem_oid oid; - uint32_t index; - DECL_SENTINEL -}; - -struct flushlist_node { - struct ramster_remotify_hdr rem_op; - struct tmem_xhandle xh; -}; - -union { - struct ramster_remotify_hdr rem_op; - struct zv_hdr zv; - struct zbud_hdr zbud; - struct flushlist_node flist; -} remotify_list_node; - -static LIST_HEAD(zcache_rem_op_list); -static DEFINE_SPINLOCK(zcache_rem_op_list_lock); - -#if 0 -/* this is more aggressive but may cause other problems? */ -#define ZCACHE_GFP_MASK (GFP_ATOMIC | __GFP_NORETRY | __GFP_NOWARN) -#else -#define ZCACHE_GFP_MASK \ - (__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC) -#endif - -#define MAX_POOLS_PER_CLIENT 16 - -#define MAX_CLIENTS 16 -#define LOCAL_CLIENT ((uint16_t)-1) - -MODULE_LICENSE("GPL"); - -struct zcache_client { - struct tmem_pool *tmem_pools[MAX_POOLS_PER_CLIENT]; - struct xv_pool *xvpool; - bool allocated; - atomic_t refcount; -}; - -static struct zcache_client zcache_host; -static struct zcache_client zcache_clients[MAX_CLIENTS]; - -static inline uint16_t get_client_id_from_client(struct zcache_client *cli) -{ - BUG_ON(cli == NULL); - if (cli == &zcache_host) - return LOCAL_CLIENT; - return cli - &zcache_clients[0]; -} - -static inline bool is_local_client(struct zcache_client *cli) -{ - return cli == &zcache_host; -} - -/********** - * Compression buddies ("zbud") provides for packing two (or, possibly - * in the future, more) compressed ephemeral pages into a single "raw" - * (physical) page and tracking them with data structures so that - * the raw pages can be easily reclaimed. - * - * A zbud page ("zbpg") is an aligned page containing a list_head, - * a lock, and two "zbud headers". The remainder of the physical - * page is divided up into aligned 64-byte "chunks" which contain - * the compressed data for zero, one, or two zbuds. Each zbpg - * resides on: (1) an "unused list" if it has no zbuds; (2) a - * "buddied" list if it is fully populated with two zbuds; or - * (3) one of PAGE_SIZE/64 "unbuddied" lists indexed by how many chunks - * the one unbuddied zbud uses. The data inside a zbpg cannot be - * read or written unless the zbpg's lock is held. - */ - -struct zbud_page { - struct list_head bud_list; - spinlock_t lock; - struct zbud_hdr buddy[ZBUD_MAX_BUDS]; - DECL_SENTINEL - /* followed by NUM_CHUNK aligned CHUNK_SIZE-byte chunks */ -}; - -#define CHUNK_SHIFT 6 -#define CHUNK_SIZE (1 << CHUNK_SHIFT) -#define CHUNK_MASK (~(CHUNK_SIZE-1)) -#define NCHUNKS (((PAGE_SIZE - sizeof(struct zbud_page)) & \ - CHUNK_MASK) >> CHUNK_SHIFT) -#define MAX_CHUNK (NCHUNKS-1) - -static struct { - struct list_head list; - unsigned count; -} zbud_unbuddied[NCHUNKS]; -/* list N contains pages with N chunks USED and NCHUNKS-N unused */ -/* element 0 is never used but optimizing that isn't worth it */ -static unsigned long zbud_cumul_chunk_counts[NCHUNKS]; - -struct list_head zbud_buddied_list; -static unsigned long zcache_zbud_buddied_count; - -/* protects the buddied list and all unbuddied lists */ -static DEFINE_SPINLOCK(zbud_budlists_spinlock); - -static atomic_t zcache_zbud_curr_raw_pages; -static atomic_t zcache_zbud_curr_zpages; -static unsigned long zcache_zbud_curr_zbytes; -static unsigned long zcache_zbud_cumul_zpages; -static unsigned long zcache_zbud_cumul_zbytes; -static unsigned long zcache_compress_poor; -static unsigned long zcache_policy_percent_exceeded; -static unsigned long zcache_mean_compress_poor; - -/* - * RAMster counters - * - Remote pages are pages with a local pampd but the data is remote - * - Foreign pages are pages stored locally but belonging to another node - */ -static atomic_t ramster_remote_pers_pages = ATOMIC_INIT(0); -static unsigned long ramster_pers_remotify_enable; -static unsigned long ramster_eph_remotify_enable; -static unsigned long ramster_eph_pages_remoted; -static unsigned long ramster_eph_pages_remote_failed; -static unsigned long ramster_pers_pages_remoted; -static unsigned long ramster_pers_pages_remote_failed; -static unsigned long ramster_pers_pages_remote_nomem; -static unsigned long ramster_remote_objects_flushed; -static unsigned long ramster_remote_object_flushes_failed; -static unsigned long ramster_remote_pages_flushed; -static unsigned long ramster_remote_page_flushes_failed; -static unsigned long ramster_remote_eph_pages_succ_get; -static unsigned long ramster_remote_pers_pages_succ_get; -static unsigned long ramster_remote_eph_pages_unsucc_get; -static unsigned long ramster_remote_pers_pages_unsucc_get; -static atomic_t ramster_curr_flnode_count = ATOMIC_INIT(0); -static unsigned long ramster_curr_flnode_count_max; -static atomic_t ramster_foreign_eph_pampd_count = ATOMIC_INIT(0); -static unsigned long ramster_foreign_eph_pampd_count_max; -static atomic_t ramster_foreign_pers_pampd_count = ATOMIC_INIT(0); -static unsigned long ramster_foreign_pers_pampd_count_max; - -/* forward references */ -static void *zcache_get_free_page(void); -static void zcache_free_page(void *p); - -/* - * zbud helper functions - */ - -static inline unsigned zbud_max_buddy_size(void) -{ - return MAX_CHUNK << CHUNK_SHIFT; -} - -static inline unsigned zbud_size_to_chunks(unsigned size) -{ - BUG_ON(size == 0 || size > zbud_max_buddy_size()); - return (size + CHUNK_SIZE - 1) >> CHUNK_SHIFT; -} - -static inline int zbud_budnum(struct zbud_hdr *zh) -{ - unsigned offset = (unsigned long)zh & (PAGE_SIZE - 1); - struct zbud_page *zbpg = NULL; - unsigned budnum = -1U; - int i; - - for (i = 0; i < ZBUD_MAX_BUDS; i++) - if (offset == offsetof(typeof(*zbpg), buddy[i])) { - budnum = i; - break; - } - BUG_ON(budnum == -1U); - return budnum; -} - -static char *zbud_data(struct zbud_hdr *zh, unsigned size) -{ - struct zbud_page *zbpg; - char *p; - unsigned budnum; - - ASSERT_SENTINEL(zh, ZBH); - budnum = zbud_budnum(zh); - BUG_ON(size == 0 || size > zbud_max_buddy_size()); - zbpg = container_of(zh, struct zbud_page, buddy[budnum]); - ASSERT_SPINLOCK(&zbpg->lock); - p = (char *)zbpg; - if (budnum == 0) - p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) & - CHUNK_MASK); - else if (budnum == 1) - p += PAGE_SIZE - ((size + CHUNK_SIZE - 1) & CHUNK_MASK); - return p; -} - -static void zbud_copy_from_pampd(char *data, size_t *size, struct zbud_hdr *zh) -{ - struct zbud_page *zbpg; - char *p; - unsigned budnum; - - ASSERT_SENTINEL(zh, ZBH); - budnum = zbud_budnum(zh); - zbpg = container_of(zh, struct zbud_page, buddy[budnum]); - spin_lock(&zbpg->lock); - BUG_ON(zh->size > *size); - p = (char *)zbpg; - if (budnum == 0) - p += ((sizeof(struct zbud_page) + CHUNK_SIZE - 1) & - CHUNK_MASK); - else if (budnum == 1) - p += PAGE_SIZE - ((zh->size + CHUNK_SIZE - 1) & CHUNK_MASK); - /* client should be filled in by caller */ - memcpy(data, p, zh->size); - *size = zh->size; - spin_unlock(&zbpg->lock); -} - -/* - * zbud raw page management - */ - -static struct zbud_page *zbud_alloc_raw_page(void) -{ - struct zbud_page *zbpg = NULL; - struct zbud_hdr *zh0, *zh1; - zbpg = zcache_get_free_page(); - if (likely(zbpg != NULL)) { - INIT_LIST_HEAD(&zbpg->bud_list); - zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; - spin_lock_init(&zbpg->lock); - atomic_inc(&zcache_zbud_curr_raw_pages); - INIT_LIST_HEAD(&zbpg->bud_list); - SET_SENTINEL(zbpg, ZBPG); - zh0->size = 0; zh1->size = 0; - tmem_oid_set_invalid(&zh0->oid); - tmem_oid_set_invalid(&zh1->oid); - } - return zbpg; -} - -static void zbud_free_raw_page(struct zbud_page *zbpg) -{ - struct zbud_hdr *zh0 = &zbpg->buddy[0], *zh1 = &zbpg->buddy[1]; - - ASSERT_SENTINEL(zbpg, ZBPG); - BUG_ON(!list_empty(&zbpg->bud_list)); - ASSERT_SPINLOCK(&zbpg->lock); - BUG_ON(zh0->size != 0 || tmem_oid_valid(&zh0->oid)); - BUG_ON(zh1->size != 0 || tmem_oid_valid(&zh1->oid)); - INVERT_SENTINEL(zbpg, ZBPG); - spin_unlock(&zbpg->lock); - atomic_dec(&zcache_zbud_curr_raw_pages); - zcache_free_page(zbpg); -} - -/* - * core zbud handling routines - */ - -static unsigned zbud_free(struct zbud_hdr *zh) -{ - unsigned size; - - ASSERT_SENTINEL(zh, ZBH); - BUG_ON(!tmem_oid_valid(&zh->oid)); - size = zh->size; - BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); - zh->size = 0; - tmem_oid_set_invalid(&zh->oid); - INVERT_SENTINEL(zh, ZBH); - zcache_zbud_curr_zbytes -= size; - atomic_dec(&zcache_zbud_curr_zpages); - return size; -} - -static void zbud_free_and_delist(struct zbud_hdr *zh) -{ - unsigned chunks; - struct zbud_hdr *zh_other; - unsigned budnum = zbud_budnum(zh), size; - struct zbud_page *zbpg = - container_of(zh, struct zbud_page, buddy[budnum]); - - /* FIXME, should be BUG_ON, pool destruction path doesn't disable - * interrupts tmem_destroy_pool()->tmem_pampd_destroy_all_in_obj()-> - * tmem_objnode_node_destroy()-> zcache_pampd_free() */ - WARN_ON(!irqs_disabled()); - spin_lock(&zbpg->lock); - if (list_empty(&zbpg->bud_list)) { - /* ignore zombie page... see zbud_evict_pages() */ - spin_unlock(&zbpg->lock); - return; - } - size = zbud_free(zh); - ASSERT_SPINLOCK(&zbpg->lock); - zh_other = &zbpg->buddy[(budnum == 0) ? 1 : 0]; - if (zh_other->size == 0) { /* was unbuddied: unlist and free */ - chunks = zbud_size_to_chunks(size) ; - spin_lock(&zbud_budlists_spinlock); - BUG_ON(list_empty(&zbud_unbuddied[chunks].list)); - list_del_init(&zbpg->bud_list); - zbud_unbuddied[chunks].count--; - spin_unlock(&zbud_budlists_spinlock); - zbud_free_raw_page(zbpg); - } else { /* was buddied: move remaining buddy to unbuddied list */ - chunks = zbud_size_to_chunks(zh_other->size) ; - spin_lock(&zbud_budlists_spinlock); - list_del_init(&zbpg->bud_list); - zcache_zbud_buddied_count--; - list_add_tail(&zbpg->bud_list, &zbud_unbuddied[chunks].list); - zbud_unbuddied[chunks].count++; - spin_unlock(&zbud_budlists_spinlock); - spin_unlock(&zbpg->lock); - } -} - -static struct zbud_hdr *zbud_create(uint16_t client_id, uint16_t pool_id, - struct tmem_oid *oid, - uint32_t index, struct page *page, - void *cdata, unsigned size) -{ - struct zbud_hdr *zh0, *zh1, *zh = NULL; - struct zbud_page *zbpg = NULL, *ztmp; - unsigned nchunks; - char *to; - int i, found_good_buddy = 0; - - nchunks = zbud_size_to_chunks(size) ; - for (i = MAX_CHUNK - nchunks + 1; i > 0; i--) { - spin_lock(&zbud_budlists_spinlock); - if (!list_empty(&zbud_unbuddied[i].list)) { - list_for_each_entry_safe(zbpg, ztmp, - &zbud_unbuddied[i].list, bud_list) { - if (spin_trylock(&zbpg->lock)) { - found_good_buddy = i; - goto found_unbuddied; - } - } - } - spin_unlock(&zbud_budlists_spinlock); - } - /* didn't find a good buddy, try allocating a new page */ - zbpg = zbud_alloc_raw_page(); - if (unlikely(zbpg == NULL)) - goto out; - /* ok, have a page, now compress the data before taking locks */ - spin_lock(&zbud_budlists_spinlock); - spin_lock(&zbpg->lock); - list_add_tail(&zbpg->bud_list, &zbud_unbuddied[nchunks].list); - zbud_unbuddied[nchunks].count++; - zh = &zbpg->buddy[0]; - goto init_zh; - -found_unbuddied: - ASSERT_SPINLOCK(&zbpg->lock); - zh0 = &zbpg->buddy[0]; zh1 = &zbpg->buddy[1]; - BUG_ON(!((zh0->size == 0) ^ (zh1->size == 0))); - if (zh0->size != 0) { /* buddy0 in use, buddy1 is vacant */ - ASSERT_SENTINEL(zh0, ZBH); - zh = zh1; - } else if (zh1->size != 0) { /* buddy1 in use, buddy0 is vacant */ - ASSERT_SENTINEL(zh1, ZBH); - zh = zh0; - } else - BUG(); - list_del_init(&zbpg->bud_list); - zbud_unbuddied[found_good_buddy].count--; - list_add_tail(&zbpg->bud_list, &zbud_buddied_list); - zcache_zbud_buddied_count++; - -init_zh: - SET_SENTINEL(zh, ZBH); - zh->size = size; - zh->index = index; - zh->oid = *oid; - zh->pool_id = pool_id; - zh->client_id = client_id; - to = zbud_data(zh, size); - memcpy(to, cdata, size); - spin_unlock(&zbpg->lock); - spin_unlock(&zbud_budlists_spinlock); - zbud_cumul_chunk_counts[nchunks]++; - atomic_inc(&zcache_zbud_curr_zpages); - zcache_zbud_cumul_zpages++; - zcache_zbud_curr_zbytes += size; - zcache_zbud_cumul_zbytes += size; -out: - return zh; -} - -static int zbud_decompress(struct page *page, struct zbud_hdr *zh) -{ - struct zbud_page *zbpg; - unsigned budnum = zbud_budnum(zh); - size_t out_len = PAGE_SIZE; - char *to_va, *from_va; - unsigned size; - int ret = 0; - - zbpg = container_of(zh, struct zbud_page, buddy[budnum]); - spin_lock(&zbpg->lock); - if (list_empty(&zbpg->bud_list)) { - /* ignore zombie page... see zbud_evict_pages() */ - ret = -EINVAL; - goto out; - } - ASSERT_SENTINEL(zh, ZBH); - BUG_ON(zh->size == 0 || zh->size > zbud_max_buddy_size()); - to_va = kmap_atomic(page); - size = zh->size; - from_va = zbud_data(zh, size); - ret = lzo1x_decompress_safe(from_va, size, to_va, &out_len); - BUG_ON(ret != LZO_E_OK); - BUG_ON(out_len != PAGE_SIZE); - kunmap_atomic(to_va); -out: - spin_unlock(&zbpg->lock); - return ret; -} - -/* - * The following routines handle shrinking of ephemeral pages by evicting - * pages "least valuable" first. - */ - -static unsigned long zcache_evicted_raw_pages; -static unsigned long zcache_evicted_buddied_pages; -static unsigned long zcache_evicted_unbuddied_pages; - -static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, - uint16_t poolid); -static void zcache_put_pool(struct tmem_pool *pool); - -/* - * Flush and free all zbuds in a zbpg, then free the pageframe - */ -static void zbud_evict_zbpg(struct zbud_page *zbpg) -{ - struct zbud_hdr *zh; - int i, j; - uint32_t pool_id[ZBUD_MAX_BUDS], client_id[ZBUD_MAX_BUDS]; - uint32_t index[ZBUD_MAX_BUDS]; - struct tmem_oid oid[ZBUD_MAX_BUDS]; - struct tmem_pool *pool; - unsigned long flags; - - ASSERT_SPINLOCK(&zbpg->lock); - for (i = 0, j = 0; i < ZBUD_MAX_BUDS; i++) { - zh = &zbpg->buddy[i]; - if (zh->size) { - client_id[j] = zh->client_id; - pool_id[j] = zh->pool_id; - oid[j] = zh->oid; - index[j] = zh->index; - j++; - } - } - spin_unlock(&zbpg->lock); - for (i = 0; i < j; i++) { - pool = zcache_get_pool_by_id(client_id[i], pool_id[i]); - BUG_ON(pool == NULL); - local_irq_save(flags); - /* these flushes should dispose of any local storage */ - tmem_flush_page(pool, &oid[i], index[i]); - local_irq_restore(flags); - zcache_put_pool(pool); - } -} - -/* - * Free nr pages. This code is funky because we want to hold the locks - * protecting various lists for as short a time as possible, and in some - * circumstances the list may change asynchronously when the list lock is - * not held. In some cases we also trylock not only to avoid waiting on a - * page in use by another cpu, but also to avoid potential deadlock due to - * lock inversion. - */ -static void zbud_evict_pages(int nr) -{ - struct zbud_page *zbpg; - int i, newly_unused_pages = 0; - - - /* now try freeing unbuddied pages, starting with least space avail */ - for (i = 0; i < MAX_CHUNK; i++) { -retry_unbud_list_i: - spin_lock_bh(&zbud_budlists_spinlock); - if (list_empty(&zbud_unbuddied[i].list)) { - spin_unlock_bh(&zbud_budlists_spinlock); - continue; - } - list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) { - if (unlikely(!spin_trylock(&zbpg->lock))) - continue; - zbud_unbuddied[i].count--; - spin_unlock(&zbud_budlists_spinlock); - zcache_evicted_unbuddied_pages++; - /* want budlists unlocked when doing zbpg eviction */ - zbud_evict_zbpg(zbpg); - newly_unused_pages++; - local_bh_enable(); - if (--nr <= 0) - goto evict_unused; - goto retry_unbud_list_i; - } - spin_unlock_bh(&zbud_budlists_spinlock); - } - - /* as a last resort, free buddied pages */ -retry_bud_list: - spin_lock_bh(&zbud_budlists_spinlock); - if (list_empty(&zbud_buddied_list)) { - spin_unlock_bh(&zbud_budlists_spinlock); - goto evict_unused; - } - list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) { - if (unlikely(!spin_trylock(&zbpg->lock))) - continue; - zcache_zbud_buddied_count--; - spin_unlock(&zbud_budlists_spinlock); - zcache_evicted_buddied_pages++; - /* want budlists unlocked when doing zbpg eviction */ - zbud_evict_zbpg(zbpg); - newly_unused_pages++; - local_bh_enable(); - if (--nr <= 0) - goto evict_unused; - goto retry_bud_list; - } - spin_unlock_bh(&zbud_budlists_spinlock); - -evict_unused: - return; -} - -static DEFINE_PER_CPU(unsigned char *, zcache_remoteputmem); - -static int zbud_remotify_zbud(struct tmem_xhandle *xh, char *data, - size_t size) -{ - struct tmem_pool *pool; - int i, remotenode, ret = -1; - unsigned char cksum, *p; - unsigned long flags; - - for (p = data, cksum = 0, i = 0; i < size; i++) - cksum += *p; - ret = ramster_remote_put(xh, data, size, true, &remotenode); - if (ret == 0) { - /* data was successfully remoted so change the local version - * to point to the remote node where it landed */ - pool = zcache_get_pool_by_id(LOCAL_CLIENT, xh->pool_id); - BUG_ON(pool == NULL); - local_irq_save(flags); - /* tmem_replace will also free up any local space */ - (void)tmem_replace(pool, &xh->oid, xh->index, - pampd_make_remote(remotenode, size, cksum)); - local_irq_restore(flags); - zcache_put_pool(pool); - ramster_eph_pages_remoted++; - ret = 0; - } else - ramster_eph_pages_remote_failed++; - return ret; -} - -static int zbud_remotify_zbpg(struct zbud_page *zbpg) -{ - struct zbud_hdr *zh1, *zh2 = NULL; - struct tmem_xhandle xh1, xh2 = { 0 }; - char *data1 = NULL, *data2 = NULL; - size_t size1 = 0, size2 = 0; - int ret = 0; - unsigned char *tmpmem = __get_cpu_var(zcache_remoteputmem); - - ASSERT_SPINLOCK(&zbpg->lock); - if (zbpg->buddy[0].size == 0) - zh1 = &zbpg->buddy[1]; - else if (zbpg->buddy[1].size == 0) - zh1 = &zbpg->buddy[0]; - else { - zh1 = &zbpg->buddy[0]; - zh2 = &zbpg->buddy[1]; - } - /* don't remotify pages that are already remotified */ - if (zh1->client_id != LOCAL_CLIENT) - zh1 = NULL; - if ((zh2 != NULL) && (zh2->client_id != LOCAL_CLIENT)) - zh2 = NULL; - - /* copy the data and metadata so can release lock */ - if (zh1 != NULL) { - xh1.client_id = zh1->client_id; - xh1.pool_id = zh1->pool_id; - xh1.oid = zh1->oid; - xh1.index = zh1->index; - size1 = zh1->size; - data1 = zbud_data(zh1, size1); - memcpy(tmpmem, zbud_data(zh1, size1), size1); - data1 = tmpmem; - tmpmem += size1; - } - if (zh2 != NULL) { - xh2.client_id = zh2->client_id; - xh2.pool_id = zh2->pool_id; - xh2.oid = zh2->oid; - xh2.index = zh2->index; - size2 = zh2->size; - memcpy(tmpmem, zbud_data(zh2, size2), size2); - data2 = tmpmem; - } - spin_unlock(&zbpg->lock); - preempt_enable(); - - /* OK, no locks held anymore, remotify one or both zbuds */ - if (zh1 != NULL) - ret = zbud_remotify_zbud(&xh1, data1, size1); - if (zh2 != NULL) - ret |= zbud_remotify_zbud(&xh2, data2, size2); - return ret; -} - -void zbud_remotify_pages(int nr) -{ - struct zbud_page *zbpg; - int i, ret; - - /* - * for now just try remotifying unbuddied pages, starting with - * least space avail - */ - for (i = 0; i < MAX_CHUNK; i++) { -retry_unbud_list_i: - preempt_disable(); /* enable in zbud_remotify_zbpg */ - spin_lock_bh(&zbud_budlists_spinlock); - if (list_empty(&zbud_unbuddied[i].list)) { - spin_unlock_bh(&zbud_budlists_spinlock); - preempt_enable(); - continue; /* next i in for loop */ - } - list_for_each_entry(zbpg, &zbud_unbuddied[i].list, bud_list) { - if (unlikely(!spin_trylock(&zbpg->lock))) - continue; /* next list_for_each_entry */ - zbud_unbuddied[i].count--; - /* want budlists unlocked when doing zbpg remotify */ - spin_unlock_bh(&zbud_budlists_spinlock); - ret = zbud_remotify_zbpg(zbpg); - /* preemption is re-enabled in zbud_remotify_zbpg */ - if (ret == 0) { - if (--nr <= 0) - goto out; - goto retry_unbud_list_i; - } - /* if fail to remotify any page, quit */ - pr_err("TESTING zbud_remotify_pages failed on page," - " trying to re-add\n"); - spin_lock_bh(&zbud_budlists_spinlock); - spin_lock(&zbpg->lock); - list_add_tail(&zbpg->bud_list, &zbud_unbuddied[i].list); - zbud_unbuddied[i].count++; - spin_unlock(&zbpg->lock); - spin_unlock_bh(&zbud_budlists_spinlock); - pr_err("TESTING zbud_remotify_pages failed on page," - " finished re-add\n"); - goto out; - } - spin_unlock_bh(&zbud_budlists_spinlock); - preempt_enable(); - } - -next_buddied_zbpg: - preempt_disable(); /* enable in zbud_remotify_zbpg */ - spin_lock_bh(&zbud_budlists_spinlock); - if (list_empty(&zbud_buddied_list)) - goto unlock_out; - list_for_each_entry(zbpg, &zbud_buddied_list, bud_list) { - if (unlikely(!spin_trylock(&zbpg->lock))) - continue; /* next list_for_each_entry */ - zcache_zbud_buddied_count--; - /* want budlists unlocked when doing zbpg remotify */ - spin_unlock_bh(&zbud_budlists_spinlock); - ret = zbud_remotify_zbpg(zbpg); - /* preemption is re-enabled in zbud_remotify_zbpg */ - if (ret == 0) { - if (--nr <= 0) - goto out; - goto next_buddied_zbpg; - } - /* if fail to remotify any page, quit */ - pr_err("TESTING zbud_remotify_pages failed on BUDDIED page," - " trying to re-add\n"); - spin_lock_bh(&zbud_budlists_spinlock); - spin_lock(&zbpg->lock); - list_add_tail(&zbpg->bud_list, &zbud_buddied_list); - zcache_zbud_buddied_count++; - spin_unlock(&zbpg->lock); - spin_unlock_bh(&zbud_budlists_spinlock); - pr_err("TESTING zbud_remotify_pages failed on BUDDIED page," - " finished re-add\n"); - goto out; - } -unlock_out: - spin_unlock_bh(&zbud_budlists_spinlock); - preempt_enable(); -out: - return; -} - -/* the "flush list" asynchronously collects pages to remotely flush */ -#define FLUSH_ENTIRE_OBJECT ((uint32_t)-1) -static void ramster_flnode_free(struct flushlist_node *, - struct tmem_pool *); - -static void zcache_remote_flush_page(struct flushlist_node *flnode) -{ - struct tmem_xhandle *xh; - int remotenode, ret; - - preempt_disable(); - xh = &flnode->xh; - remotenode = flnode->xh.client_id; - ret = ramster_remote_flush(xh, remotenode); - if (ret >= 0) - ramster_remote_pages_flushed++; - else - ramster_remote_page_flushes_failed++; - preempt_enable_no_resched(); - ramster_flnode_free(flnode, NULL); -} - -static void zcache_remote_flush_object(struct flushlist_node *flnode) -{ - struct tmem_xhandle *xh; - int remotenode, ret; - - preempt_disable(); - xh = &flnode->xh; - remotenode = flnode->xh.client_id; - ret = ramster_remote_flush_object(xh, remotenode); - if (ret >= 0) - ramster_remote_objects_flushed++; - else - ramster_remote_object_flushes_failed++; - preempt_enable_no_resched(); - ramster_flnode_free(flnode, NULL); -} - -static void zcache_remote_eph_put(struct zbud_hdr *zbud) -{ - /* FIXME */ -} - -static void zcache_remote_pers_put(struct zv_hdr *zv) -{ - struct tmem_xhandle xh; - uint16_t size; - bool ephemeral; - int remotenode, ret = -1; - char *data; - struct tmem_pool *pool; - unsigned long flags; - unsigned char cksum; - char *p; - int i; - unsigned char *tmpmem = __get_cpu_var(zcache_remoteputmem); - - ASSERT_SENTINEL(zv, ZVH); - BUG_ON(zv->client_id != LOCAL_CLIENT); - local_bh_disable(); - xh.client_id = zv->client_id; - xh.pool_id = zv->pool_id; - xh.oid = zv->oid; - xh.index = zv->index; - size = xv_get_object_size(zv) - sizeof(*zv); - BUG_ON(size == 0 || size > zv_max_page_size); - data = (char *)zv + sizeof(*zv); - for (p = data, cksum = 0, i = 0; i < size; i++) - cksum += *p; - memcpy(tmpmem, data, size); - data = tmpmem; - pool = zcache_get_pool_by_id(zv->client_id, zv->pool_id); - ephemeral = is_ephemeral(pool); - zcache_put_pool(pool); - /* now OK to release lock set in caller */ - spin_unlock(&zcache_rem_op_list_lock); - local_bh_enable(); - preempt_disable(); - ret = ramster_remote_put(&xh, data, size, ephemeral, &remotenode); - preempt_enable_no_resched(); - if (ret != 0) { - /* - * This is some form of a memory leak... if the remote put - * fails, there will never be another attempt to remotify - * this page. But since we've dropped the zv pointer, - * the page may have been freed or the data replaced - * so we can't just "put it back" in the remote op list. - * Even if we could, not sure where to put it in the list - * because there may be flushes that must be strictly - * ordered vs the put. So leave this as a FIXME for now. - * But count them so we know if it becomes a problem. - */ - ramster_pers_pages_remote_failed++; - goto out; - } else - atomic_inc(&ramster_remote_pers_pages); - ramster_pers_pages_remoted++; - /* - * data was successfully remoted so change the local version to - * point to the remote node where it landed - */ - local_bh_disable(); - pool = zcache_get_pool_by_id(LOCAL_CLIENT, xh.pool_id); - local_irq_save(flags); - (void)tmem_replace(pool, &xh.oid, xh.index, - pampd_make_remote(remotenode, size, cksum)); - local_irq_restore(flags); - zcache_put_pool(pool); - local_bh_enable(); -out: - return; -} - -static void zcache_do_remotify_ops(int nr) -{ - struct ramster_remotify_hdr *rem_op; - union remotify_list_node *u; - - while (1) { - if (!nr) - goto out; - spin_lock(&zcache_rem_op_list_lock); - if (list_empty(&zcache_rem_op_list)) { - spin_unlock(&zcache_rem_op_list_lock); - goto out; - } - rem_op = list_first_entry(&zcache_rem_op_list, - struct ramster_remotify_hdr, list); - list_del_init(&rem_op->list); - if (rem_op->op != RAMSTER_REMOTIFY_PERS_PUT) - spin_unlock(&zcache_rem_op_list_lock); - u = (union remotify_list_node *)rem_op; - switch (rem_op->op) { - case RAMSTER_REMOTIFY_EPH_PUT: -BUG(); - zcache_remote_eph_put((struct zbud_hdr *)rem_op); - break; - case RAMSTER_REMOTIFY_PERS_PUT: - zcache_remote_pers_put((struct zv_hdr *)rem_op); - break; - case RAMSTER_REMOTIFY_FLUSH_PAGE: - zcache_remote_flush_page((struct flushlist_node *)u); - break; - case RAMSTER_REMOTIFY_FLUSH_OBJ: - zcache_remote_flush_object((struct flushlist_node *)u); - break; - default: - BUG(); - } - } -out: - return; -} - -/* - * Communicate interface revision with userspace - */ -#include "cluster/ramster_nodemanager.h" -static unsigned long ramster_interface_revision = R2NM_API_VERSION; - -/* - * For now, just push over a few pages every few seconds to - * ensure that it basically works - */ -static struct workqueue_struct *ramster_remotify_workqueue; -static void ramster_remotify_process(struct work_struct *work); -static DECLARE_DELAYED_WORK(ramster_remotify_worker, - ramster_remotify_process); - -static void ramster_remotify_queue_delayed_work(unsigned long delay) -{ - if (!queue_delayed_work(ramster_remotify_workqueue, - &ramster_remotify_worker, delay)) - pr_err("ramster_remotify: bad workqueue\n"); -} - - -static int use_frontswap; -static int use_cleancache; -static int ramster_remote_target_nodenum = -1; -static void ramster_remotify_process(struct work_struct *work) -{ - static bool remotify_in_progress; - - BUG_ON(irqs_disabled()); - if (remotify_in_progress) - ramster_remotify_queue_delayed_work(HZ); - else if (ramster_remote_target_nodenum != -1) { - remotify_in_progress = true; -#ifdef CONFIG_CLEANCACHE - if (use_cleancache && ramster_eph_remotify_enable) - zbud_remotify_pages(5000); /* FIXME is this a good number? */ -#endif -#ifdef CONFIG_FRONTSWAP - if (use_frontswap && ramster_pers_remotify_enable) - zcache_do_remotify_ops(500); /* FIXME is this a good number? */ -#endif - remotify_in_progress = false; - ramster_remotify_queue_delayed_work(HZ); - } -} - -static void ramster_remotify_init(void) -{ - unsigned long n = 60UL; - ramster_remotify_workqueue = - create_singlethread_workqueue("ramster_remotify"); - ramster_remotify_queue_delayed_work(n * HZ); -} - - -static void zbud_init(void) -{ - int i; - - INIT_LIST_HEAD(&zbud_buddied_list); - zcache_zbud_buddied_count = 0; - for (i = 0; i < NCHUNKS; i++) { - INIT_LIST_HEAD(&zbud_unbuddied[i].list); - zbud_unbuddied[i].count = 0; - } -} - -#ifdef CONFIG_SYSFS -/* - * These sysfs routines show a nice distribution of how many zbpg's are - * currently (and have ever been placed) in each unbuddied list. It's fun - * to watch but can probably go away before final merge. - */ -static int zbud_show_unbuddied_list_counts(char *buf) -{ - int i; - char *p = buf; - - for (i = 0; i < NCHUNKS; i++) - p += sprintf(p, "%u ", zbud_unbuddied[i].count); - return p - buf; -} - -static int zbud_show_cumul_chunk_counts(char *buf) -{ - unsigned long i, chunks = 0, total_chunks = 0, sum_total_chunks = 0; - unsigned long total_chunks_lte_21 = 0, total_chunks_lte_32 = 0; - unsigned long total_chunks_lte_42 = 0; - char *p = buf; - - for (i = 0; i < NCHUNKS; i++) { - p += sprintf(p, "%lu ", zbud_cumul_chunk_counts[i]); - chunks += zbud_cumul_chunk_counts[i]; - total_chunks += zbud_cumul_chunk_counts[i]; - sum_total_chunks += i * zbud_cumul_chunk_counts[i]; - if (i == 21) - total_chunks_lte_21 = total_chunks; - if (i == 32) - total_chunks_lte_32 = total_chunks; - if (i == 42) - total_chunks_lte_42 = total_chunks; - } - p += sprintf(p, "<=21:%lu <=32:%lu <=42:%lu, mean:%lu\n", - total_chunks_lte_21, total_chunks_lte_32, total_chunks_lte_42, - chunks == 0 ? 0 : sum_total_chunks / chunks); - return p - buf; -} -#endif - -/********** - * This "zv" PAM implementation combines the TLSF-based xvMalloc - * with lzo1x compression to maximize the amount of data that can - * be packed into a physical page. - * - * Zv represents a PAM page with the index and object (plus a "size" value - * necessary for decompression) immediately preceding the compressed data. - */ - -/* rudimentary policy limits */ -/* total number of persistent pages may not exceed this percentage */ -static unsigned int zv_page_count_policy_percent = 75; -/* - * byte count defining poor compression; pages with greater zsize will be - * rejected - */ -static unsigned int zv_max_zsize = (PAGE_SIZE / 8) * 7; -/* - * byte count defining poor *mean* compression; pages with greater zsize - * will be rejected until sufficient better-compressed pages are accepted - * driving the mean below this threshold - */ -static unsigned int zv_max_mean_zsize = (PAGE_SIZE / 8) * 5; - -static atomic_t zv_curr_dist_counts[NCHUNKS]; -static atomic_t zv_cumul_dist_counts[NCHUNKS]; - - -static struct zv_hdr *zv_create(struct zcache_client *cli, uint32_t pool_id, - struct tmem_oid *oid, uint32_t index, - void *cdata, unsigned clen) -{ - struct page *page; - struct zv_hdr *zv = NULL; - uint32_t offset; - int alloc_size = clen + sizeof(struct zv_hdr); - int chunks = (alloc_size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT; - int ret; - - BUG_ON(!irqs_disabled()); - BUG_ON(chunks >= NCHUNKS); - ret = xv_malloc(cli->xvpool, clen + sizeof(struct zv_hdr), - &page, &offset, ZCACHE_GFP_MASK); - if (unlikely(ret)) - goto out; - atomic_inc(&zv_curr_dist_counts[chunks]); - atomic_inc(&zv_cumul_dist_counts[chunks]); - zv = kmap_atomic(page) + offset; - zv->index = index; - zv->oid = *oid; - zv->pool_id = pool_id; - SET_SENTINEL(zv, ZVH); - INIT_LIST_HEAD(&zv->rem_op.list); - zv->client_id = get_client_id_from_client(cli); - zv->rem_op.op = RAMSTER_REMOTIFY_PERS_PUT; - if (zv->client_id == LOCAL_CLIENT) { - spin_lock(&zcache_rem_op_list_lock); - list_add_tail(&zv->rem_op.list, &zcache_rem_op_list); - spin_unlock(&zcache_rem_op_list_lock); - } - memcpy((char *)zv + sizeof(struct zv_hdr), cdata, clen); - kunmap_atomic(zv); -out: - return zv; -} - -/* similar to zv_create, but just reserve space, no data yet */ -static struct zv_hdr *zv_alloc(struct tmem_pool *pool, - struct tmem_oid *oid, uint32_t index, - unsigned clen) -{ - struct zcache_client *cli = pool->client; - struct page *page; - struct zv_hdr *zv = NULL; - uint32_t offset; - int ret; - - BUG_ON(!irqs_disabled()); - BUG_ON(!is_local_client(pool->client)); - ret = xv_malloc(cli->xvpool, clen + sizeof(struct zv_hdr), - &page, &offset, ZCACHE_GFP_MASK); - if (unlikely(ret)) - goto out; - zv = kmap_atomic(page) + offset; - SET_SENTINEL(zv, ZVH); - INIT_LIST_HEAD(&zv->rem_op.list); - zv->client_id = LOCAL_CLIENT; - zv->rem_op.op = RAMSTER_INTRANSIT_PERS; - zv->index = index; - zv->oid = *oid; - zv->pool_id = pool->pool_id; - kunmap_atomic(zv); -out: - return zv; -} - -static void zv_free(struct xv_pool *xvpool, struct zv_hdr *zv) -{ - unsigned long flags; - struct page *page; - uint32_t offset; - uint16_t size = xv_get_object_size(zv); - int chunks = (size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT; - - ASSERT_SENTINEL(zv, ZVH); - BUG_ON(chunks >= NCHUNKS); - atomic_dec(&zv_curr_dist_counts[chunks]); - size -= sizeof(*zv); - spin_lock(&zcache_rem_op_list_lock); - size = xv_get_object_size(zv) - sizeof(*zv); - BUG_ON(size == 0); - INVERT_SENTINEL(zv, ZVH); - if (!list_empty(&zv->rem_op.list)) - list_del_init(&zv->rem_op.list); - spin_unlock(&zcache_rem_op_list_lock); - page = virt_to_page(zv); - offset = (unsigned long)zv & ~PAGE_MASK; - local_irq_save(flags); - xv_free(xvpool, page, offset); - local_irq_restore(flags); -} - -static void zv_decompress(struct page *page, struct zv_hdr *zv) -{ - size_t clen = PAGE_SIZE; - char *to_va; - unsigned size; - int ret; - - ASSERT_SENTINEL(zv, ZVH); - size = xv_get_object_size(zv) - sizeof(*zv); - BUG_ON(size == 0); - to_va = kmap_atomic(page); - ret = lzo1x_decompress_safe((char *)zv + sizeof(*zv), - size, to_va, &clen); - kunmap_atomic(to_va); - BUG_ON(ret != LZO_E_OK); - BUG_ON(clen != PAGE_SIZE); -} - -static void zv_copy_from_pampd(char *data, size_t *bufsize, struct zv_hdr *zv) -{ - unsigned size; - - ASSERT_SENTINEL(zv, ZVH); - size = xv_get_object_size(zv) - sizeof(*zv); - BUG_ON(size == 0 || size > zv_max_page_size); - BUG_ON(size > *bufsize); - memcpy(data, (char *)zv + sizeof(*zv), size); - *bufsize = size; -} - -static void zv_copy_to_pampd(struct zv_hdr *zv, char *data, size_t size) -{ - unsigned zv_size; - - ASSERT_SENTINEL(zv, ZVH); - zv_size = xv_get_object_size(zv) - sizeof(*zv); - BUG_ON(zv_size != size); - BUG_ON(zv_size == 0 || zv_size > zv_max_page_size); - memcpy((char *)zv + sizeof(*zv), data, size); -} - -#ifdef CONFIG_SYSFS -/* - * show a distribution of compression stats for zv pages. - */ - -static int zv_curr_dist_counts_show(char *buf) -{ - unsigned long i, n, chunks = 0, sum_total_chunks = 0; - char *p = buf; - - for (i = 0; i < NCHUNKS; i++) { - n = atomic_read(&zv_curr_dist_counts[i]); - p += sprintf(p, "%lu ", n); - chunks += n; - sum_total_chunks += i * n; - } - p += sprintf(p, "mean:%lu\n", - chunks == 0 ? 0 : sum_total_chunks / chunks); - return p - buf; -} - -static int zv_cumul_dist_counts_show(char *buf) -{ - unsigned long i, n, chunks = 0, sum_total_chunks = 0; - char *p = buf; - - for (i = 0; i < NCHUNKS; i++) { - n = atomic_read(&zv_cumul_dist_counts[i]); - p += sprintf(p, "%lu ", n); - chunks += n; - sum_total_chunks += i * n; - } - p += sprintf(p, "mean:%lu\n", - chunks == 0 ? 0 : sum_total_chunks / chunks); - return p - buf; -} - -/* - * setting zv_max_zsize via sysfs causes all persistent (e.g. swap) - * pages that don't compress to less than this value (including metadata - * overhead) to be rejected. We don't allow the value to get too close - * to PAGE_SIZE. - */ -static ssize_t zv_max_zsize_show(struct kobject *kobj, - struct kobj_attribute *attr, - char *buf) -{ - return sprintf(buf, "%u\n", zv_max_zsize); -} - -static ssize_t zv_max_zsize_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t count) -{ - unsigned long val; - int err; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - err = kstrtoul(buf, 10, &val); - if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7)) - return -EINVAL; - zv_max_zsize = val; - return count; -} - -/* - * setting zv_max_mean_zsize via sysfs causes all persistent (e.g. swap) - * pages that don't compress to less than this value (including metadata - * overhead) to be rejected UNLESS the mean compression is also smaller - * than this value. In other words, we are load-balancing-by-zsize the - * accepted pages. Again, we don't allow the value to get too close - * to PAGE_SIZE. - */ -static ssize_t zv_max_mean_zsize_show(struct kobject *kobj, - struct kobj_attribute *attr, - char *buf) -{ - return sprintf(buf, "%u\n", zv_max_mean_zsize); -} - -static ssize_t zv_max_mean_zsize_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t count) -{ - unsigned long val; - int err; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - err = kstrtoul(buf, 10, &val); - if (err || (val == 0) || (val > (PAGE_SIZE / 8) * 7)) - return -EINVAL; - zv_max_mean_zsize = val; - return count; -} - -/* - * setting zv_page_count_policy_percent via sysfs sets an upper bound of - * persistent (e.g. swap) pages that will be retained according to: - * (zv_page_count_policy_percent * totalram_pages) / 100) - * when that limit is reached, further puts will be rejected (until - * some pages have been flushed). Note that, due to compression, - * this number may exceed 100; it defaults to 75 and we set an - * arbitrary limit of 150. A poor choice will almost certainly result - * in OOM's, so this value should only be changed prudently. - */ -static ssize_t zv_page_count_policy_percent_show(struct kobject *kobj, - struct kobj_attribute *attr, - char *buf) -{ - return sprintf(buf, "%u\n", zv_page_count_policy_percent); -} - -static ssize_t zv_page_count_policy_percent_store(struct kobject *kobj, - struct kobj_attribute *attr, - const char *buf, size_t count) -{ - unsigned long val; - int err; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - err = kstrtoul(buf, 10, &val); - if (err || (val == 0) || (val > 150)) - return -EINVAL; - zv_page_count_policy_percent = val; - return count; -} - -static struct kobj_attribute zcache_zv_max_zsize_attr = { - .attr = { .name = "zv_max_zsize", .mode = 0644 }, - .show = zv_max_zsize_show, - .store = zv_max_zsize_store, -}; - -static struct kobj_attribute zcache_zv_max_mean_zsize_attr = { - .attr = { .name = "zv_max_mean_zsize", .mode = 0644 }, - .show = zv_max_mean_zsize_show, - .store = zv_max_mean_zsize_store, -}; - -static struct kobj_attribute zcache_zv_page_count_policy_percent_attr = { - .attr = { .name = "zv_page_count_policy_percent", - .mode = 0644 }, - .show = zv_page_count_policy_percent_show, - .store = zv_page_count_policy_percent_store, -}; -#endif - -/* - * zcache core code starts here - */ - -/* useful stats not collected by cleancache or frontswap */ -static unsigned long zcache_flush_total; -static unsigned long zcache_flush_found; -static unsigned long zcache_flobj_total; -static unsigned long zcache_flobj_found; -static unsigned long zcache_failed_eph_puts; -static unsigned long zcache_nonactive_puts; -static unsigned long zcache_failed_pers_puts; - -/* - * Tmem operations assume the poolid implies the invoking client. - * Zcache only has one client (the kernel itself): LOCAL_CLIENT. - * RAMster has each client numbered by cluster node, and a KVM version - * of zcache would have one client per guest and each client might - * have a poolid==N. - */ -static struct tmem_pool *zcache_get_pool_by_id(uint16_t cli_id, uint16_t poolid) -{ - struct tmem_pool *pool = NULL; - struct zcache_client *cli = NULL; - - if (cli_id == LOCAL_CLIENT) - cli = &zcache_host; - else { - if (cli_id >= MAX_CLIENTS) - goto out; - cli = &zcache_clients[cli_id]; - if (cli == NULL) - goto out; - atomic_inc(&cli->refcount); - } - if (poolid < MAX_POOLS_PER_CLIENT) { - pool = cli->tmem_pools[poolid]; - if (pool != NULL) - atomic_inc(&pool->refcount); - } -out: - return pool; -} - -static void zcache_put_pool(struct tmem_pool *pool) -{ - struct zcache_client *cli = NULL; - - if (pool == NULL) - BUG(); - cli = pool->client; - atomic_dec(&pool->refcount); - atomic_dec(&cli->refcount); -} - -int zcache_new_client(uint16_t cli_id) -{ - struct zcache_client *cli = NULL; - int ret = -1; - - if (cli_id == LOCAL_CLIENT) - cli = &zcache_host; - else if ((unsigned int)cli_id < MAX_CLIENTS) - cli = &zcache_clients[cli_id]; - if (cli == NULL) - goto out; - if (cli->allocated) - goto out; - cli->allocated = 1; -#ifdef CONFIG_FRONTSWAP - cli->xvpool = xv_create_pool(); - if (cli->xvpool == NULL) - goto out; -#endif - ret = 0; -out: - return ret; -} - -/* counters for debugging */ -static unsigned long zcache_failed_get_free_pages; -static unsigned long zcache_failed_alloc; -static unsigned long zcache_put_to_flush; - -/* - * for now, used named slabs so can easily track usage; later can - * either just use kmalloc, or perhaps add a slab-like allocator - * to more carefully manage total memory utilization - */ -static struct kmem_cache *zcache_objnode_cache; -static struct kmem_cache *zcache_obj_cache; -static struct kmem_cache *ramster_flnode_cache; -static atomic_t zcache_curr_obj_count = ATOMIC_INIT(0); -static unsigned long zcache_curr_obj_count_max; -static atomic_t zcache_curr_objnode_count = ATOMIC_INIT(0); -static unsigned long zcache_curr_objnode_count_max; - -/* - * to avoid memory allocation recursion (e.g. due to direct reclaim), we - * preload all necessary data structures so the hostops callbacks never - * actually do a malloc - */ -struct zcache_preload { - void *page; - struct tmem_obj *obj; - int nr; - struct tmem_objnode *objnodes[OBJNODE_TREE_MAX_PATH]; - struct flushlist_node *flnode; -}; -static DEFINE_PER_CPU(struct zcache_preload, zcache_preloads) = { 0, }; - -static int zcache_do_preload(struct tmem_pool *pool) -{ - struct zcache_preload *kp; - struct tmem_objnode *objnode; - struct tmem_obj *obj; - struct flushlist_node *flnode; - void *page; - int ret = -ENOMEM; - - if (unlikely(zcache_objnode_cache == NULL)) - goto out; - if (unlikely(zcache_obj_cache == NULL)) - goto out; - preempt_disable(); - kp = &__get_cpu_var(zcache_preloads); - while (kp->nr < ARRAY_SIZE(kp->objnodes)) { - preempt_enable_no_resched(); - objnode = kmem_cache_alloc(zcache_objnode_cache, - ZCACHE_GFP_MASK); - if (unlikely(objnode == NULL)) { - zcache_failed_alloc++; - goto out; - } - preempt_disable(); - kp = &__get_cpu_var(zcache_preloads); - if (kp->nr < ARRAY_SIZE(kp->objnodes)) - kp->objnodes[kp->nr++] = objnode; - else - kmem_cache_free(zcache_objnode_cache, objnode); - } - preempt_enable_no_resched(); - obj = kmem_cache_alloc(zcache_obj_cache, ZCACHE_GFP_MASK); - if (unlikely(obj == NULL)) { - zcache_failed_alloc++; - goto out; - } - flnode = kmem_cache_alloc(ramster_flnode_cache, ZCACHE_GFP_MASK); - if (unlikely(flnode == NULL)) { - zcache_failed_alloc++; - goto out; - } - if (is_ephemeral(pool)) { - page = (void *)__get_free_page(ZCACHE_GFP_MASK); - if (unlikely(page == NULL)) { - zcache_failed_get_free_pages++; - kmem_cache_free(zcache_obj_cache, obj); - kmem_cache_free(ramster_flnode_cache, flnode); - goto out; - } - } - preempt_disable(); - kp = &__get_cpu_var(zcache_preloads); - if (kp->obj == NULL) - kp->obj = obj; - else - kmem_cache_free(zcache_obj_cache, obj); - if (kp->flnode == NULL) - kp->flnode = flnode; - else - kmem_cache_free(ramster_flnode_cache, flnode); - if (is_ephemeral(pool)) { - if (kp->page == NULL) - kp->page = page; - else - free_page((unsigned long)page); - } - ret = 0; -out: - return ret; -} - -static int ramster_do_preload_flnode_only(struct tmem_pool *pool) -{ - struct zcache_preload *kp; - struct flushlist_node *flnode; - int ret = -ENOMEM; - - BUG_ON(!irqs_disabled()); - if (unlikely(ramster_flnode_cache == NULL)) - BUG(); - kp = &__get_cpu_var(zcache_preloads); - flnode = kmem_cache_alloc(ramster_flnode_cache, GFP_ATOMIC); - if (unlikely(flnode == NULL) && kp->flnode == NULL) - BUG(); /* FIXME handle more gracefully, but how??? */ - else if (kp->flnode == NULL) - kp->flnode = flnode; - else - kmem_cache_free(ramster_flnode_cache, flnode); - return ret; -} - -static void *zcache_get_free_page(void) -{ - struct zcache_preload *kp; - void *page; - - kp = &__get_cpu_var(zcache_preloads); - page = kp->page; - BUG_ON(page == NULL); - kp->page = NULL; - return page; -} - -static void zcache_free_page(void *p) -{ - free_page((unsigned long)p); -} - -/* - * zcache implementation for tmem host ops - */ - -static struct tmem_objnode *zcache_objnode_alloc(struct tmem_pool *pool) -{ - struct tmem_objnode *objnode = NULL; - unsigned long count; - struct zcache_preload *kp; - - kp = &__get_cpu_var(zcache_preloads); - if (kp->nr <= 0) - goto out; - objnode = kp->objnodes[kp->nr - 1]; - BUG_ON(objnode == NULL); - kp->objnodes[kp->nr - 1] = NULL; - kp->nr--; - count = atomic_inc_return(&zcache_curr_objnode_count); - if (count > zcache_curr_objnode_count_max) - zcache_curr_objnode_count_max = count; -out: - return objnode; -} - -static void zcache_objnode_free(struct tmem_objnode *objnode, - struct tmem_pool *pool) -{ - atomic_dec(&zcache_curr_objnode_count); - BUG_ON(atomic_read(&zcache_curr_objnode_count) < 0); - kmem_cache_free(zcache_objnode_cache, objnode); -} - -static struct tmem_obj *zcache_obj_alloc(struct tmem_pool *pool) -{ - struct tmem_obj *obj = NULL; - unsigned long count; - struct zcache_preload *kp; - - kp = &__get_cpu_var(zcache_preloads); - obj = kp->obj; - BUG_ON(obj == NULL); - kp->obj = NULL; - count = atomic_inc_return(&zcache_curr_obj_count); - if (count > zcache_curr_obj_count_max) - zcache_curr_obj_count_max = count; - return obj; -} - -static void zcache_obj_free(struct tmem_obj *obj, struct tmem_pool *pool) -{ - atomic_dec(&zcache_curr_obj_count); - BUG_ON(atomic_read(&zcache_curr_obj_count) < 0); - kmem_cache_free(zcache_obj_cache, obj); -} - -static struct flushlist_node *ramster_flnode_alloc(struct tmem_pool *pool) -{ - struct flushlist_node *flnode = NULL; - struct zcache_preload *kp; - int count; - - kp = &__get_cpu_var(zcache_preloads); - flnode = kp->flnode; - BUG_ON(flnode == NULL); - kp->flnode = NULL; - count = atomic_inc_return(&ramster_curr_flnode_count); - if (count > ramster_curr_flnode_count_max) - ramster_curr_flnode_count_max = count; - return flnode; -} - -static void ramster_flnode_free(struct flushlist_node *flnode, - struct tmem_pool *pool) -{ - atomic_dec(&ramster_curr_flnode_count); - BUG_ON(atomic_read(&ramster_curr_flnode_count) < 0); - kmem_cache_free(ramster_flnode_cache, flnode); -} - -static struct tmem_hostops zcache_hostops = { - .obj_alloc = zcache_obj_alloc, - .obj_free = zcache_obj_free, - .objnode_alloc = zcache_objnode_alloc, - .objnode_free = zcache_objnode_free, -}; - -/* - * zcache implementations for PAM page descriptor ops - */ - - -static inline void dec_and_check(atomic_t *pvar) -{ - atomic_dec(pvar); - /* later when all accounting is fixed, make this a BUG */ - WARN_ON_ONCE(atomic_read(pvar) < 0); -} - -static atomic_t zcache_curr_eph_pampd_count = ATOMIC_INIT(0); -static unsigned long zcache_curr_eph_pampd_count_max; -static atomic_t zcache_curr_pers_pampd_count = ATOMIC_INIT(0); -static unsigned long zcache_curr_pers_pampd_count_max; - -/* forward reference */ -static int zcache_compress(struct page *from, void **out_va, size_t *out_len); - -static int zcache_pampd_eph_create(char *data, size_t size, bool raw, - struct tmem_pool *pool, struct tmem_oid *oid, - uint32_t index, void **pampd) -{ - int ret = -1; - void *cdata = data; - size_t clen = size; - struct zcache_client *cli = pool->client; - uint16_t client_id = get_client_id_from_client(cli); - struct page *page = NULL; - unsigned long count; - - if (!raw) { - page = virt_to_page(data); - ret = zcache_compress(page, &cdata, &clen); - if (ret == 0) - goto out; - if (clen == 0 || clen > zbud_max_buddy_size()) { - zcache_compress_poor++; - goto out; - } - } - *pampd = (void *)zbud_create(client_id, pool->pool_id, oid, - index, page, cdata, clen); - if (*pampd == NULL) { - ret = -ENOMEM; - goto out; - } - ret = 0; - count = atomic_inc_return(&zcache_curr_eph_pampd_count); - if (count > zcache_curr_eph_pampd_count_max) - zcache_curr_eph_pampd_count_max = count; - if (client_id != LOCAL_CLIENT) { - count = atomic_inc_return(&ramster_foreign_eph_pampd_count); - if (count > ramster_foreign_eph_pampd_count_max) - ramster_foreign_eph_pampd_count_max = count; - } -out: - return ret; -} - -static int zcache_pampd_pers_create(char *data, size_t size, bool raw, - struct tmem_pool *pool, struct tmem_oid *oid, - uint32_t index, void **pampd) -{ - int ret = -1; - void *cdata = data; - size_t clen = size; - struct zcache_client *cli = pool->client; - struct page *page; - unsigned long count; - unsigned long zv_mean_zsize; - struct zv_hdr *zv; - long curr_pers_pampd_count; - u64 total_zsize; -#ifdef RAMSTER_TESTING - static bool pampd_neg_warned; -#endif - - curr_pers_pampd_count = atomic_read(&zcache_curr_pers_pampd_count) - - atomic_read(&ramster_remote_pers_pages); -#ifdef RAMSTER_TESTING - /* should always be positive, but warn if accounting is off */ - if (!pampd_neg_warned) { - pr_warn("ramster: bad accounting for curr_pers_pampd_count\n"); - pampd_neg_warned = true; - } -#endif - if (curr_pers_pampd_count > - (zv_page_count_policy_percent * totalram_pages) / 100) { - zcache_policy_percent_exceeded++; - goto out; - } - if (raw) - goto ok_to_create; - page = virt_to_page(data); - if (zcache_compress(page, &cdata, &clen) == 0) - goto out; - /* reject if compression is too poor */ - if (clen > zv_max_zsize) { - zcache_compress_poor++; - goto out; - } - /* reject if mean compression is too poor */ - if ((clen > zv_max_mean_zsize) && (curr_pers_pampd_count > 0)) { - total_zsize = xv_get_total_size_bytes(cli->xvpool); - zv_mean_zsize = div_u64(total_zsize, curr_pers_pampd_count); - if (zv_mean_zsize > zv_max_mean_zsize) { - zcache_mean_compress_poor++; - goto out; - } - } -ok_to_create: - *pampd = (void *)zv_create(cli, pool->pool_id, oid, index, cdata, clen); - if (*pampd == NULL) { - ret = -ENOMEM; - goto out; - } - ret = 0; - count = atomic_inc_return(&zcache_curr_pers_pampd_count); - if (count > zcache_curr_pers_pampd_count_max) - zcache_curr_pers_pampd_count_max = count; - if (is_local_client(cli)) - goto out; - zv = *(struct zv_hdr **)pampd; - count = atomic_inc_return(&ramster_foreign_pers_pampd_count); - if (count > ramster_foreign_pers_pampd_count_max) - ramster_foreign_pers_pampd_count_max = count; -out: - return ret; -} - -static void *zcache_pampd_create(char *data, size_t size, bool raw, int eph, - struct tmem_pool *pool, struct tmem_oid *oid, - uint32_t index) -{ - void *pampd = NULL; - int ret; - bool ephemeral; - - BUG_ON(preemptible()); - ephemeral = (eph == 1) || ((eph == 0) && is_ephemeral(pool)); - if (ephemeral) - ret = zcache_pampd_eph_create(data, size, raw, pool, - oid, index, &pampd); - else - ret = zcache_pampd_pers_create(data, size, raw, pool, - oid, index, &pampd); - /* FIXME add some counters here for failed creates? */ - return pampd; -} - -/* - * fill the pageframe corresponding to the struct page with the data - * from the passed pampd - */ -static int zcache_pampd_get_data(char *data, size_t *bufsize, bool raw, - void *pampd, struct tmem_pool *pool, - struct tmem_oid *oid, uint32_t index) -{ - int ret = 0; - - BUG_ON(preemptible()); - BUG_ON(is_ephemeral(pool)); /* Fix later for shared pools? */ - BUG_ON(pampd_is_remote(pampd)); - if (raw) - zv_copy_from_pampd(data, bufsize, pampd); - else - zv_decompress(virt_to_page(data), pampd); - return ret; -} - -static int zcache_pampd_get_data_and_free(char *data, size_t *bufsize, bool raw, - void *pampd, struct tmem_pool *pool, - struct tmem_oid *oid, uint32_t index) -{ - int ret = 0; - unsigned long flags; - struct zcache_client *cli = pool->client; - - BUG_ON(preemptible()); - BUG_ON(pampd_is_remote(pampd)); - if (is_ephemeral(pool)) { - local_irq_save(flags); - if (raw) - zbud_copy_from_pampd(data, bufsize, pampd); - else - ret = zbud_decompress(virt_to_page(data), pampd); - zbud_free_and_delist((struct zbud_hdr *)pampd); - local_irq_restore(flags); - if (!is_local_client(cli)) - dec_and_check(&ramster_foreign_eph_pampd_count); - dec_and_check(&zcache_curr_eph_pampd_count); - } else { - if (is_local_client(cli)) - BUG(); - if (raw) - zv_copy_from_pampd(data, bufsize, pampd); - else - zv_decompress(virt_to_page(data), pampd); - zv_free(cli->xvpool, pampd); - if (!is_local_client(cli)) - dec_and_check(&ramster_foreign_pers_pampd_count); - dec_and_check(&zcache_curr_pers_pampd_count); - ret = 0; - } - return ret; -} - -static bool zcache_pampd_is_remote(void *pampd) -{ - return pampd_is_remote(pampd); -} - -/* - * free the pampd and remove it from any zcache lists - * pampd must no longer be pointed to from any tmem data structures! - */ -static void zcache_pampd_free(void *pampd, struct tmem_pool *pool, - struct tmem_oid *oid, uint32_t index, bool acct) -{ - struct zcache_client *cli = pool->client; - bool eph = is_ephemeral(pool); - struct zv_hdr *zv; - - BUG_ON(preemptible()); - if (pampd_is_remote(pampd)) { - WARN_ON(acct == false); - if (oid == NULL) { - /* - * a NULL oid means to ignore this pampd free - * as the remote freeing will be handled elsewhere - */ - } else if (eph) { - /* FIXME remote flush optional but probably good idea */ - /* FIXME get these working properly again */ - dec_and_check(&zcache_curr_eph_pampd_count); - } else if (pampd_is_intransit(pampd)) { - /* did a pers remote get_and_free, so just free local */ - pampd = pampd_mask_intransit_and_remote(pampd); - goto local_pers; - } else { - struct flushlist_node *flnode = - ramster_flnode_alloc(pool); - - flnode->xh.client_id = pampd_remote_node(pampd); - flnode->xh.pool_id = pool->pool_id; - flnode->xh.oid = *oid; - flnode->xh.index = index; - flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_PAGE; - spin_lock(&zcache_rem_op_list_lock); - list_add(&flnode->rem_op.list, &zcache_rem_op_list); - spin_unlock(&zcache_rem_op_list_lock); - dec_and_check(&zcache_curr_pers_pampd_count); - dec_and_check(&ramster_remote_pers_pages); - } - } else if (eph) { - zbud_free_and_delist((struct zbud_hdr *)pampd); - if (!is_local_client(pool->client)) - dec_and_check(&ramster_foreign_eph_pampd_count); - if (acct) - /* FIXME get these working properly again */ - dec_and_check(&zcache_curr_eph_pampd_count); - } else { -local_pers: - zv = (struct zv_hdr *)pampd; - if (!is_local_client(pool->client)) - dec_and_check(&ramster_foreign_pers_pampd_count); - zv_free(cli->xvpool, zv); - if (acct) - /* FIXME get these working properly again */ - dec_and_check(&zcache_curr_pers_pampd_count); - } -} - -static void zcache_pampd_free_obj(struct tmem_pool *pool, - struct tmem_obj *obj) -{ - struct flushlist_node *flnode; - - BUG_ON(preemptible()); - if (obj->extra == NULL) - return; - BUG_ON(!pampd_is_remote(obj->extra)); - flnode = ramster_flnode_alloc(pool); - flnode->xh.client_id = pampd_remote_node(obj->extra); - flnode->xh.pool_id = pool->pool_id; - flnode->xh.oid = obj->oid; - flnode->xh.index = FLUSH_ENTIRE_OBJECT; - flnode->rem_op.op = RAMSTER_REMOTIFY_FLUSH_OBJ; - spin_lock(&zcache_rem_op_list_lock); - list_add(&flnode->rem_op.list, &zcache_rem_op_list); - spin_unlock(&zcache_rem_op_list_lock); -} - -void zcache_pampd_new_obj(struct tmem_obj *obj) -{ - obj->extra = NULL; -} - -int zcache_pampd_replace_in_obj(void *new_pampd, struct tmem_obj *obj) -{ - int ret = -1; - - if (new_pampd != NULL) { - if (obj->extra == NULL) - obj->extra = new_pampd; - /* enforce that all remote pages in an object reside - * in the same node! */ - else if (pampd_remote_node(new_pampd) != - pampd_remote_node((void *)(obj->extra))) - BUG(); - ret = 0; - } - return ret; -} - -/* - * Called by the message handler after a (still compressed) page has been - * fetched from the remote machine in response to an "is_remote" tmem_get - * or persistent tmem_localify. For a tmem_get, "extra" is the address of - * the page that is to be filled to successfully resolve the tmem_get; for - * a (persistent) tmem_localify, "extra" is NULL (as the data is placed only - * in the local zcache). "data" points to "size" bytes of (compressed) data - * passed in the message. In the case of a persistent remote get, if - * pre-allocation was successful (see zcache_repatriate_preload), the page - * is placed into both local zcache and at "extra". - */ -int zcache_localify(int pool_id, struct tmem_oid *oidp, - uint32_t index, char *data, size_t size, - void *extra) -{ - int ret = -ENOENT; - unsigned long flags; - struct tmem_pool *pool; - bool ephemeral, delete = false; - size_t clen = PAGE_SIZE; - void *pampd, *saved_hb; - struct tmem_obj *obj; - - pool = zcache_get_pool_by_id(LOCAL_CLIENT, pool_id); - if (unlikely(pool == NULL)) - /* pool doesn't exist anymore */ - goto out; - ephemeral = is_ephemeral(pool); - local_irq_save(flags); /* FIXME: maybe only disable softirqs? */ - pampd = tmem_localify_get_pampd(pool, oidp, index, &obj, &saved_hb); - if (pampd == NULL) { - /* hmmm... must have been a flush while waiting */ -#ifdef RAMSTER_TESTING - pr_err("UNTESTED pampd==NULL in zcache_localify\n"); -#endif - if (ephemeral) - ramster_remote_eph_pages_unsucc_get++; - else - ramster_remote_pers_pages_unsucc_get++; - obj = NULL; - goto finish; - } else if (unlikely(!pampd_is_remote(pampd))) { - /* hmmm... must have been a dup put while waiting */ -#ifdef RAMSTER_TESTING - pr_err("UNTESTED dup while waiting in zcache_localify\n"); -#endif - if (ephemeral) - ramster_remote_eph_pages_unsucc_get++; - else - ramster_remote_pers_pages_unsucc_get++; - obj = NULL; - pampd = NULL; - ret = -EEXIST; - goto finish; - } else if (size == 0) { - /* no remote data, delete the local is_remote pampd */ - pampd = NULL; - if (ephemeral) - ramster_remote_eph_pages_unsucc_get++; - else - BUG(); - delete = true; - goto finish; - } - if (!ephemeral && pampd_is_intransit(pampd)) { - /* localify to zcache */ - pampd = pampd_mask_intransit_and_remote(pampd); - zv_copy_to_pampd(pampd, data, size); - } else { - pampd = NULL; - obj = NULL; - } - if (extra != NULL) { - /* decompress direct-to-memory to complete remotify */ - ret = lzo1x_decompress_safe((char *)data, size, - (char *)extra, &clen); - BUG_ON(ret != LZO_E_OK); - BUG_ON(clen != PAGE_SIZE); - } - if (ephemeral) - ramster_remote_eph_pages_succ_get++; - else - ramster_remote_pers_pages_succ_get++; - ret = 0; -finish: - tmem_localify_finish(obj, index, pampd, saved_hb, delete); - zcache_put_pool(pool); - local_irq_restore(flags); -out: - return ret; -} - -/* - * Called on a remote persistent tmem_get to attempt to preallocate - * local storage for the data contained in the remote persistent page. - * If successfully preallocated, returns the pampd, marked as remote and - * in_transit. Else returns NULL. Note that the appropriate tmem data - * structure must be locked. - */ -static void *zcache_pampd_repatriate_preload(void *pampd, - struct tmem_pool *pool, - struct tmem_oid *oid, - uint32_t index, - bool *intransit) -{ - int clen = pampd_remote_size(pampd); - void *ret_pampd = NULL; - unsigned long flags; - - if (!pampd_is_remote(pampd)) - BUG(); - if (is_ephemeral(pool)) - BUG(); - if (pampd_is_intransit(pampd)) { - /* - * to avoid multiple allocations (and maybe a memory leak) - * don't preallocate if already in the process of being - * repatriated - */ - *intransit = true; - goto out; - } - *intransit = false; - local_irq_save(flags); - ret_pampd = (void *)zv_alloc(pool, oid, index, clen); - if (ret_pampd != NULL) { - /* - * a pampd is marked intransit if it is remote and space has - * been allocated for it locally (note, only happens for - * persistent pages, in which case the remote copy is freed) - */ - ret_pampd = pampd_mark_intransit(ret_pampd); - dec_and_check(&ramster_remote_pers_pages); - } else - ramster_pers_pages_remote_nomem++; - local_irq_restore(flags); -out: - return ret_pampd; -} - -/* - * Called on a remote tmem_get to invoke a message to fetch the page. - * Might sleep so no tmem locks can be held. "extra" is passed - * all the way through the round-trip messaging to zcache_localify. - */ -static int zcache_pampd_repatriate(void *fake_pampd, void *real_pampd, - struct tmem_pool *pool, - struct tmem_oid *oid, uint32_t index, - bool free, void *extra) -{ - struct tmem_xhandle xh; - int ret; - - if (pampd_is_intransit(real_pampd)) - /* have local space pre-reserved, so free remote copy */ - free = true; - xh = tmem_xhandle_fill(LOCAL_CLIENT, pool, oid, index); - /* unreliable request/response for now */ - ret = ramster_remote_async_get(&xh, free, - pampd_remote_node(fake_pampd), - pampd_remote_size(fake_pampd), - pampd_remote_cksum(fake_pampd), - extra); -#ifdef RAMSTER_TESTING - if (ret != 0 && ret != -ENOENT) - pr_err("TESTING zcache_pampd_repatriate returns, ret=%d\n", - ret); -#endif - return ret; -} - -static struct tmem_pamops zcache_pamops = { - .create = zcache_pampd_create, - .get_data = zcache_pampd_get_data, - .free = zcache_pampd_free, - .get_data_and_free = zcache_pampd_get_data_and_free, - .free_obj = zcache_pampd_free_obj, - .is_remote = zcache_pampd_is_remote, - .repatriate_preload = zcache_pampd_repatriate_preload, - .repatriate = zcache_pampd_repatriate, - .new_obj = zcache_pampd_new_obj, - .replace_in_obj = zcache_pampd_replace_in_obj, -}; - -/* - * zcache compression/decompression and related per-cpu stuff - */ - -#define LZO_WORKMEM_BYTES LZO1X_1_MEM_COMPRESS -#define LZO_DSTMEM_PAGE_ORDER 1 -static DEFINE_PER_CPU(unsigned char *, zcache_workmem); -static DEFINE_PER_CPU(unsigned char *, zcache_dstmem); - -static int zcache_compress(struct page *from, void **out_va, size_t *out_len) -{ - int ret = 0; - unsigned char *dmem = __get_cpu_var(zcache_dstmem); - unsigned char *wmem = __get_cpu_var(zcache_workmem); - char *from_va; - - BUG_ON(!irqs_disabled()); - if (unlikely(dmem == NULL || wmem == NULL)) - goto out; /* no buffer, so can't compress */ - from_va = kmap_atomic(from); - mb(); - ret = lzo1x_1_compress(from_va, PAGE_SIZE, dmem, out_len, wmem); - BUG_ON(ret != LZO_E_OK); - *out_va = dmem; - kunmap_atomic(from_va); - ret = 1; -out: - return ret; -} - - -static int zcache_cpu_notifier(struct notifier_block *nb, - unsigned long action, void *pcpu) -{ - int cpu = (long)pcpu; - struct zcache_preload *kp; - - switch (action) { - case CPU_UP_PREPARE: - per_cpu(zcache_dstmem, cpu) = (void *)__get_free_pages( - GFP_KERNEL | __GFP_REPEAT, - LZO_DSTMEM_PAGE_ORDER), - per_cpu(zcache_workmem, cpu) = - kzalloc(LZO1X_MEM_COMPRESS, - GFP_KERNEL | __GFP_REPEAT); - per_cpu(zcache_remoteputmem, cpu) = - kzalloc(PAGE_SIZE, GFP_KERNEL | __GFP_REPEAT); - break; - case CPU_DEAD: - case CPU_UP_CANCELED: - kfree(per_cpu(zcache_remoteputmem, cpu)); - per_cpu(zcache_remoteputmem, cpu) = NULL; - free_pages((unsigned long)per_cpu(zcache_dstmem, cpu), - LZO_DSTMEM_PAGE_ORDER); - per_cpu(zcache_dstmem, cpu) = NULL; - kfree(per_cpu(zcache_workmem, cpu)); - per_cpu(zcache_workmem, cpu) = NULL; - kp = &per_cpu(zcache_preloads, cpu); - while (kp->nr) { - kmem_cache_free(zcache_objnode_cache, - kp->objnodes[kp->nr - 1]); - kp->objnodes[kp->nr - 1] = NULL; - kp->nr--; - } - if (kp->obj) { - kmem_cache_free(zcache_obj_cache, kp->obj); - kp->obj = NULL; - } - if (kp->flnode) { - kmem_cache_free(ramster_flnode_cache, kp->flnode); - kp->flnode = NULL; - } - if (kp->page) { - free_page((unsigned long)kp->page); - kp->page = NULL; - } - break; - default: - break; - } - return NOTIFY_OK; -} - -static struct notifier_block zcache_cpu_notifier_block = { - .notifier_call = zcache_cpu_notifier -}; - -#ifdef CONFIG_SYSFS -#define ZCACHE_SYSFS_RO(_name) \ - static ssize_t zcache_##_name##_show(struct kobject *kobj, \ - struct kobj_attribute *attr, char *buf) \ - { \ - return sprintf(buf, "%lu\n", zcache_##_name); \ - } \ - static struct kobj_attribute zcache_##_name##_attr = { \ - .attr = { .name = __stringify(_name), .mode = 0444 }, \ - .show = zcache_##_name##_show, \ - } - -#define ZCACHE_SYSFS_RO_ATOMIC(_name) \ - static ssize_t zcache_##_name##_show(struct kobject *kobj, \ - struct kobj_attribute *attr, char *buf) \ - { \ - return sprintf(buf, "%d\n", atomic_read(&zcache_##_name)); \ - } \ - static struct kobj_attribute zcache_##_name##_attr = { \ - .attr = { .name = __stringify(_name), .mode = 0444 }, \ - .show = zcache_##_name##_show, \ - } - -#define ZCACHE_SYSFS_RO_CUSTOM(_name, _func) \ - static ssize_t zcache_##_name##_show(struct kobject *kobj, \ - struct kobj_attribute *attr, char *buf) \ - { \ - return _func(buf); \ - } \ - static struct kobj_attribute zcache_##_name##_attr = { \ - .attr = { .name = __stringify(_name), .mode = 0444 }, \ - .show = zcache_##_name##_show, \ - } - -ZCACHE_SYSFS_RO(curr_obj_count_max); -ZCACHE_SYSFS_RO(curr_objnode_count_max); -ZCACHE_SYSFS_RO(flush_total); -ZCACHE_SYSFS_RO(flush_found); -ZCACHE_SYSFS_RO(flobj_total); -ZCACHE_SYSFS_RO(flobj_found); -ZCACHE_SYSFS_RO(failed_eph_puts); -ZCACHE_SYSFS_RO(nonactive_puts); -ZCACHE_SYSFS_RO(failed_pers_puts); -ZCACHE_SYSFS_RO(zbud_curr_zbytes); -ZCACHE_SYSFS_RO(zbud_cumul_zpages); -ZCACHE_SYSFS_RO(zbud_cumul_zbytes); -ZCACHE_SYSFS_RO(zbud_buddied_count); -ZCACHE_SYSFS_RO(evicted_raw_pages); -ZCACHE_SYSFS_RO(evicted_unbuddied_pages); -ZCACHE_SYSFS_RO(evicted_buddied_pages); -ZCACHE_SYSFS_RO(failed_get_free_pages); -ZCACHE_SYSFS_RO(failed_alloc); -ZCACHE_SYSFS_RO(put_to_flush); -ZCACHE_SYSFS_RO(compress_poor); -ZCACHE_SYSFS_RO(mean_compress_poor); -ZCACHE_SYSFS_RO(policy_percent_exceeded); -ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_raw_pages); -ZCACHE_SYSFS_RO_ATOMIC(zbud_curr_zpages); -ZCACHE_SYSFS_RO_ATOMIC(curr_obj_count); -ZCACHE_SYSFS_RO_ATOMIC(curr_objnode_count); -ZCACHE_SYSFS_RO_CUSTOM(zbud_unbuddied_list_counts, - zbud_show_unbuddied_list_counts); -ZCACHE_SYSFS_RO_CUSTOM(zbud_cumul_chunk_counts, - zbud_show_cumul_chunk_counts); -ZCACHE_SYSFS_RO_CUSTOM(zv_curr_dist_counts, - zv_curr_dist_counts_show); -ZCACHE_SYSFS_RO_CUSTOM(zv_cumul_dist_counts, - zv_cumul_dist_counts_show); - -static struct attribute *zcache_attrs[] = { - &zcache_curr_obj_count_attr.attr, - &zcache_curr_obj_count_max_attr.attr, - &zcache_curr_objnode_count_attr.attr, - &zcache_curr_objnode_count_max_attr.attr, - &zcache_flush_total_attr.attr, - &zcache_flobj_total_attr.attr, - &zcache_flush_found_attr.attr, - &zcache_flobj_found_attr.attr, - &zcache_failed_eph_puts_attr.attr, - &zcache_nonactive_puts_attr.attr, - &zcache_failed_pers_puts_attr.attr, - &zcache_policy_percent_exceeded_attr.attr, - &zcache_compress_poor_attr.attr, - &zcache_mean_compress_poor_attr.attr, - &zcache_zbud_curr_raw_pages_attr.attr, - &zcache_zbud_curr_zpages_attr.attr, - &zcache_zbud_curr_zbytes_attr.attr, - &zcache_zbud_cumul_zpages_attr.attr, - &zcache_zbud_cumul_zbytes_attr.attr, - &zcache_zbud_buddied_count_attr.attr, - &zcache_evicted_raw_pages_attr.attr, - &zcache_evicted_unbuddied_pages_attr.attr, - &zcache_evicted_buddied_pages_attr.attr, - &zcache_failed_get_free_pages_attr.attr, - &zcache_failed_alloc_attr.attr, - &zcache_put_to_flush_attr.attr, - &zcache_zbud_unbuddied_list_counts_attr.attr, - &zcache_zbud_cumul_chunk_counts_attr.attr, - &zcache_zv_curr_dist_counts_attr.attr, - &zcache_zv_cumul_dist_counts_attr.attr, - &zcache_zv_max_zsize_attr.attr, - &zcache_zv_max_mean_zsize_attr.attr, - &zcache_zv_page_count_policy_percent_attr.attr, - NULL, -}; - -static struct attribute_group zcache_attr_group = { - .attrs = zcache_attrs, - .name = "zcache", -}; - -#define RAMSTER_SYSFS_RO(_name) \ - static ssize_t ramster_##_name##_show(struct kobject *kobj, \ - struct kobj_attribute *attr, char *buf) \ - { \ - return sprintf(buf, "%lu\n", ramster_##_name); \ - } \ - static struct kobj_attribute ramster_##_name##_attr = { \ - .attr = { .name = __stringify(_name), .mode = 0444 }, \ - .show = ramster_##_name##_show, \ - } - -#define RAMSTER_SYSFS_RW(_name) \ - static ssize_t ramster_##_name##_show(struct kobject *kobj, \ - struct kobj_attribute *attr, char *buf) \ - { \ - return sprintf(buf, "%lu\n", ramster_##_name); \ - } \ - static ssize_t ramster_##_name##_store(struct kobject *kobj, \ - struct kobj_attribute *attr, const char *buf, size_t count) \ - { \ - int err; \ - unsigned long enable; \ - err = kstrtoul(buf, 10, &enable); \ - if (err) \ - return -EINVAL; \ - ramster_##_name = enable; \ - return count; \ - } \ - static struct kobj_attribute ramster_##_name##_attr = { \ - .attr = { .name = __stringify(_name), .mode = 0644 }, \ - .show = ramster_##_name##_show, \ - .store = ramster_##_name##_store, \ - } - -#define RAMSTER_SYSFS_RO_ATOMIC(_name) \ - static ssize_t ramster_##_name##_show(struct kobject *kobj, \ - struct kobj_attribute *attr, char *buf) \ - { \ - return sprintf(buf, "%d\n", atomic_read(&ramster_##_name)); \ - } \ - static struct kobj_attribute ramster_##_name##_attr = { \ - .attr = { .name = __stringify(_name), .mode = 0444 }, \ - .show = ramster_##_name##_show, \ - } - -RAMSTER_SYSFS_RO(interface_revision); -RAMSTER_SYSFS_RO_ATOMIC(remote_pers_pages); -RAMSTER_SYSFS_RW(pers_remotify_enable); -RAMSTER_SYSFS_RW(eph_remotify_enable); -RAMSTER_SYSFS_RO(eph_pages_remoted); -RAMSTER_SYSFS_RO(eph_pages_remote_failed); -RAMSTER_SYSFS_RO(pers_pages_remoted); -RAMSTER_SYSFS_RO(pers_pages_remote_failed); -RAMSTER_SYSFS_RO(pers_pages_remote_nomem); -RAMSTER_SYSFS_RO(remote_pages_flushed); -RAMSTER_SYSFS_RO(remote_page_flushes_failed); -RAMSTER_SYSFS_RO(remote_objects_flushed); -RAMSTER_SYSFS_RO(remote_object_flushes_failed); -RAMSTER_SYSFS_RO(remote_eph_pages_succ_get); -RAMSTER_SYSFS_RO(remote_eph_pages_unsucc_get); -RAMSTER_SYSFS_RO(remote_pers_pages_succ_get); -RAMSTER_SYSFS_RO(remote_pers_pages_unsucc_get); -RAMSTER_SYSFS_RO_ATOMIC(foreign_eph_pampd_count); -RAMSTER_SYSFS_RO(foreign_eph_pampd_count_max); -RAMSTER_SYSFS_RO_ATOMIC(foreign_pers_pampd_count); -RAMSTER_SYSFS_RO(foreign_pers_pampd_count_max); -RAMSTER_SYSFS_RO_ATOMIC(curr_flnode_count); -RAMSTER_SYSFS_RO(curr_flnode_count_max); - -#define MANUAL_NODES 8 -static bool ramster_nodes_manual_up[MANUAL_NODES]; -static ssize_t ramster_manual_node_up_show(struct kobject *kobj, - struct kobj_attribute *attr, char *buf) -{ - int i; - char *p = buf; - for (i = 0; i < MANUAL_NODES; i++) - if (ramster_nodes_manual_up[i]) - p += sprintf(p, "%d ", i); - p += sprintf(p, "\n"); - return p - buf; -} - -static ssize_t ramster_manual_node_up_store(struct kobject *kobj, - struct kobj_attribute *attr, const char *buf, size_t count) -{ - int err; - unsigned long node_num; - - err = kstrtoul(buf, 10, &node_num); - if (err) { - pr_err("ramster: bad strtoul?\n"); - return -EINVAL; - } - if (node_num >= MANUAL_NODES) { - pr_err("ramster: bad node_num=%lu?\n", node_num); - return -EINVAL; - } - if (ramster_nodes_manual_up[node_num]) { - pr_err("ramster: node %d already up, ignoring\n", - (int)node_num); - } else { - ramster_nodes_manual_up[node_num] = true; - r2net_hb_node_up_manual((int)node_num); - } - return count; -} - -static struct kobj_attribute ramster_manual_node_up_attr = { - .attr = { .name = "manual_node_up", .mode = 0644 }, - .show = ramster_manual_node_up_show, - .store = ramster_manual_node_up_store, -}; - -static ssize_t ramster_remote_target_nodenum_show(struct kobject *kobj, - struct kobj_attribute *attr, char *buf) -{ - if (ramster_remote_target_nodenum == -1UL) - return sprintf(buf, "unset\n"); - else - return sprintf(buf, "%d\n", ramster_remote_target_nodenum); -} - -static ssize_t ramster_remote_target_nodenum_store(struct kobject *kobj, - struct kobj_attribute *attr, const char *buf, size_t count) -{ - int err; - unsigned long node_num; - - err = kstrtoul(buf, 10, &node_num); - if (err) { - pr_err("ramster: bad strtoul?\n"); - return -EINVAL; - } else if (node_num == -1UL) { - pr_err("ramster: disabling all remotification, " - "data may still reside on remote nodes however\n"); - return -EINVAL; - } else if (node_num >= MANUAL_NODES) { - pr_err("ramster: bad node_num=%lu?\n", node_num); - return -EINVAL; - } else if (!ramster_nodes_manual_up[node_num]) { - pr_err("ramster: node %d not up, ignoring setting " - "of remotification target\n", (int)node_num); - } else if (r2net_remote_target_node_set((int)node_num) >= 0) { - pr_info("ramster: node %d set as remotification target\n", - (int)node_num); - ramster_remote_target_nodenum = (int)node_num; - } else { - pr_err("ramster: bad num to node node_num=%d?\n", - (int)node_num); - return -EINVAL; - } - return count; -} - -static struct kobj_attribute ramster_remote_target_nodenum_attr = { - .attr = { .name = "remote_target_nodenum", .mode = 0644 }, - .show = ramster_remote_target_nodenum_show, - .store = ramster_remote_target_nodenum_store, -}; - - -static struct attribute *ramster_attrs[] = { - &ramster_interface_revision_attr.attr, - &ramster_pers_remotify_enable_attr.attr, - &ramster_eph_remotify_enable_attr.attr, - &ramster_remote_pers_pages_attr.attr, - &ramster_eph_pages_remoted_attr.attr, - &ramster_eph_pages_remote_failed_attr.attr, - &ramster_pers_pages_remoted_attr.attr, - &ramster_pers_pages_remote_failed_attr.attr, - &ramster_pers_pages_remote_nomem_attr.attr, - &ramster_remote_pages_flushed_attr.attr, - &ramster_remote_page_flushes_failed_attr.attr, - &ramster_remote_objects_flushed_attr.attr, - &ramster_remote_object_flushes_failed_attr.attr, - &ramster_remote_eph_pages_succ_get_attr.attr, - &ramster_remote_eph_pages_unsucc_get_attr.attr, - &ramster_remote_pers_pages_succ_get_attr.attr, - &ramster_remote_pers_pages_unsucc_get_attr.attr, - &ramster_foreign_eph_pampd_count_attr.attr, - &ramster_foreign_eph_pampd_count_max_attr.attr, - &ramster_foreign_pers_pampd_count_attr.attr, - &ramster_foreign_pers_pampd_count_max_attr.attr, - &ramster_curr_flnode_count_attr.attr, - &ramster_curr_flnode_count_max_attr.attr, - &ramster_manual_node_up_attr.attr, - &ramster_remote_target_nodenum_attr.attr, - NULL, -}; - -static struct attribute_group ramster_attr_group = { - .attrs = ramster_attrs, - .name = "ramster", -}; - -#endif /* CONFIG_SYSFS */ -/* - * When zcache is disabled ("frozen"), pools can be created and destroyed, - * but all puts (and thus all other operations that require memory allocation) - * must fail. If zcache is unfrozen, accepts puts, then frozen again, - * data consistency requires all puts while frozen to be converted into - * flushes. - */ -static bool zcache_freeze; - -/* - * zcache shrinker interface (only useful for ephemeral pages, so zbud only) - */ -static int shrink_zcache_memory(struct shrinker *shrink, - struct shrink_control *sc) -{ - int ret = -1; - int nr = sc->nr_to_scan; - gfp_t gfp_mask = sc->gfp_mask; - - if (nr >= 0) { - if (!(gfp_mask & __GFP_FS)) - /* does this case really need to be skipped? */ - goto out; - zbud_evict_pages(nr); - } - ret = (int)atomic_read(&zcache_zbud_curr_raw_pages); -out: - return ret; -} - -static struct shrinker zcache_shrinker = { - .shrink = shrink_zcache_memory, - .seeks = DEFAULT_SEEKS, -}; - -/* - * zcache shims between cleancache/frontswap ops and tmem - */ - -int zcache_put(int cli_id, int pool_id, struct tmem_oid *oidp, - uint32_t index, char *data, size_t size, - bool raw, int ephemeral) -{ - struct tmem_pool *pool; - int ret = -1; - - BUG_ON(!irqs_disabled()); - pool = zcache_get_pool_by_id(cli_id, pool_id); - if (unlikely(pool == NULL)) - goto out; - if (!zcache_freeze && zcache_do_preload(pool) == 0) { - /* preload does preempt_disable on success */ - ret = tmem_put(pool, oidp, index, data, size, raw, ephemeral); - if (ret < 0) { - if (is_ephemeral(pool)) - zcache_failed_eph_puts++; - else - zcache_failed_pers_puts++; - } - zcache_put_pool(pool); - preempt_enable_no_resched(); - } else { - zcache_put_to_flush++; - if (atomic_read(&pool->obj_count) > 0) - /* the put fails whether the flush succeeds or not */ - (void)tmem_flush_page(pool, oidp, index); - zcache_put_pool(pool); - } -out: - return ret; -} - -int zcache_get(int cli_id, int pool_id, struct tmem_oid *oidp, - uint32_t index, char *data, size_t *sizep, - bool raw, int get_and_free) -{ - struct tmem_pool *pool; - int ret = -1; - bool eph; - - if (!raw) { - BUG_ON(irqs_disabled()); - BUG_ON(in_softirq()); - } - pool = zcache_get_pool_by_id(cli_id, pool_id); - eph = is_ephemeral(pool); - if (likely(pool != NULL)) { - if (atomic_read(&pool->obj_count) > 0) - ret = tmem_get(pool, oidp, index, data, sizep, - raw, get_and_free); - zcache_put_pool(pool); - } - WARN_ONCE((!eph && (ret != 0)), "zcache_get fails on persistent pool, " - "bad things are very likely to happen soon\n"); -#ifdef RAMSTER_TESTING - if (ret != 0 && ret != -1 && !(ret == -EINVAL && is_ephemeral(pool))) - pr_err("TESTING zcache_get tmem_get returns ret=%d\n", ret); -#endif - if (ret == -EAGAIN) - BUG(); /* FIXME... don't need this anymore??? let's ensure */ - return ret; -} - -int zcache_flush(int cli_id, int pool_id, - struct tmem_oid *oidp, uint32_t index) -{ - struct tmem_pool *pool; - int ret = -1; - unsigned long flags; - - local_irq_save(flags); - zcache_flush_total++; - pool = zcache_get_pool_by_id(cli_id, pool_id); - ramster_do_preload_flnode_only(pool); - if (likely(pool != NULL)) { - if (atomic_read(&pool->obj_count) > 0) - ret = tmem_flush_page(pool, oidp, index); - zcache_put_pool(pool); - } - if (ret >= 0) - zcache_flush_found++; - local_irq_restore(flags); - return ret; -} - -int zcache_flush_object(int cli_id, int pool_id, struct tmem_oid *oidp) -{ - struct tmem_pool *pool; - int ret = -1; - unsigned long flags; - - local_irq_save(flags); - zcache_flobj_total++; - pool = zcache_get_pool_by_id(cli_id, pool_id); - ramster_do_preload_flnode_only(pool); - if (likely(pool != NULL)) { - if (atomic_read(&pool->obj_count) > 0) - ret = tmem_flush_object(pool, oidp); - zcache_put_pool(pool); - } - if (ret >= 0) - zcache_flobj_found++; - local_irq_restore(flags); - return ret; -} - -int zcache_client_destroy_pool(int cli_id, int pool_id) -{ - struct tmem_pool *pool = NULL; - struct zcache_client *cli = NULL; - int ret = -1; - - if (pool_id < 0) - goto out; - if (cli_id == LOCAL_CLIENT) - cli = &zcache_host; - else if ((unsigned int)cli_id < MAX_CLIENTS) - cli = &zcache_clients[cli_id]; - if (cli == NULL) - goto out; - atomic_inc(&cli->refcount); - pool = cli->tmem_pools[pool_id]; - if (pool == NULL) - goto out; - cli->tmem_pools[pool_id] = NULL; - /* wait for pool activity on other cpus to quiesce */ - while (atomic_read(&pool->refcount) != 0) - ; - atomic_dec(&cli->refcount); - local_bh_disable(); - ret = tmem_destroy_pool(pool); - local_bh_enable(); - kfree(pool); - pr_info("ramster: destroyed pool id=%d cli_id=%d\n", pool_id, cli_id); -out: - return ret; -} - -static int zcache_destroy_pool(int pool_id) -{ - return zcache_client_destroy_pool(LOCAL_CLIENT, pool_id); -} - -int zcache_new_pool(uint16_t cli_id, uint32_t flags) -{ - int poolid = -1; - struct tmem_pool *pool; - struct zcache_client *cli = NULL; - - if (cli_id == LOCAL_CLIENT) - cli = &zcache_host; - else if ((unsigned int)cli_id < MAX_CLIENTS) - cli = &zcache_clients[cli_id]; - if (cli == NULL) - goto out; - atomic_inc(&cli->refcount); - pool = kmalloc(sizeof(struct tmem_pool), GFP_ATOMIC); - if (pool == NULL) { - pr_info("ramster: pool creation failed: out of memory\n"); - goto out; - } - - for (poolid = 0; poolid < MAX_POOLS_PER_CLIENT; poolid++) - if (cli->tmem_pools[poolid] == NULL) - break; - if (poolid >= MAX_POOLS_PER_CLIENT) { - pr_info("ramster: pool creation failed: max exceeded\n"); - kfree(pool); - poolid = -1; - goto out; - } - atomic_set(&pool->refcount, 0); - pool->client = cli; - pool->pool_id = poolid; - tmem_new_pool(pool, flags); - cli->tmem_pools[poolid] = pool; - if (cli_id == LOCAL_CLIENT) - pr_info("ramster: created %s tmem pool, id=%d, local client\n", - flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", - poolid); - else - pr_info("ramster: created %s tmem pool, id=%d, client=%d\n", - flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", - poolid, cli_id); -out: - if (cli != NULL) - atomic_dec(&cli->refcount); - return poolid; -} - -static int zcache_local_new_pool(uint32_t flags) -{ - return zcache_new_pool(LOCAL_CLIENT, flags); -} - -int zcache_autocreate_pool(int cli_id, int pool_id, bool ephemeral) -{ - struct tmem_pool *pool; - struct zcache_client *cli = NULL; - uint32_t flags = ephemeral ? 0 : TMEM_POOL_PERSIST; - int ret = -1; - - if (cli_id == LOCAL_CLIENT) - goto out; - if (pool_id >= MAX_POOLS_PER_CLIENT) - goto out; - else if ((unsigned int)cli_id < MAX_CLIENTS) - cli = &zcache_clients[cli_id]; - if ((ephemeral && !use_cleancache) || (!ephemeral && !use_frontswap)) - BUG(); /* FIXME, handle more gracefully later */ - if (!cli->allocated) { - if (zcache_new_client(cli_id)) - BUG(); /* FIXME, handle more gracefully later */ - cli = &zcache_clients[cli_id]; - } - atomic_inc(&cli->refcount); - pool = cli->tmem_pools[pool_id]; - if (pool != NULL) { - if (pool->persistent && ephemeral) { - pr_err("zcache_autocreate_pool: type mismatch\n"); - goto out; - } - ret = 0; - goto out; - } - pool = kmalloc(sizeof(struct tmem_pool), GFP_KERNEL); - if (pool == NULL) { - pr_info("ramster: pool creation failed: out of memory\n"); - goto out; - } - atomic_set(&pool->refcount, 0); - pool->client = cli; - pool->pool_id = pool_id; - tmem_new_pool(pool, flags); - cli->tmem_pools[pool_id] = pool; - pr_info("ramster: AUTOcreated %s tmem poolid=%d, for remote client=%d\n", - flags & TMEM_POOL_PERSIST ? "persistent" : "ephemeral", - pool_id, cli_id); - ret = 0; -out: - if (cli == NULL) - BUG(); /* FIXME, handle more gracefully later */ - /* pr_err("zcache_autocreate_pool: failed\n"); */ - if (cli != NULL) - atomic_dec(&cli->refcount); - return ret; -} - -/********** - * Two kernel functionalities currently can be layered on top of tmem. - * These are "cleancache" which is used as a second-chance cache for clean - * page cache pages; and "frontswap" which is used for swap pages - * to avoid writes to disk. A generic "shim" is provided here for each - * to translate in-kernel semantics to zcache semantics. - */ - -#ifdef CONFIG_CLEANCACHE -static void zcache_cleancache_put_page(int pool_id, - struct cleancache_filekey key, - pgoff_t index, struct page *page) -{ - u32 ind = (u32) index; - struct tmem_oid oid = *(struct tmem_oid *)&key; - -#ifdef __PG_WAS_ACTIVE - if (!PageWasActive(page)) { - zcache_nonactive_puts++; - return; - } -#endif - if (likely(ind == index)) { - char *kva = page_address(page); - - (void)zcache_put(LOCAL_CLIENT, pool_id, &oid, index, - kva, PAGE_SIZE, 0, 1); - } -} - -static int zcache_cleancache_get_page(int pool_id, - struct cleancache_filekey key, - pgoff_t index, struct page *page) -{ - u32 ind = (u32) index; - struct tmem_oid oid = *(struct tmem_oid *)&key; - int ret = -1; - - preempt_disable(); - if (likely(ind == index)) { - char *kva = page_address(page); - size_t size = PAGE_SIZE; - - ret = zcache_get(LOCAL_CLIENT, pool_id, &oid, index, - kva, &size, 0, 0); -#ifdef __PG_WAS_ACTIVE - if (ret == 0) - SetPageWasActive(page); -#endif - } - preempt_enable(); - return ret; -} - -static void zcache_cleancache_flush_page(int pool_id, - struct cleancache_filekey key, - pgoff_t index) -{ - u32 ind = (u32) index; - struct tmem_oid oid = *(struct tmem_oid *)&key; - - if (likely(ind == index)) - (void)zcache_flush(LOCAL_CLIENT, pool_id, &oid, ind); -} - -static void zcache_cleancache_flush_inode(int pool_id, - struct cleancache_filekey key) -{ - struct tmem_oid oid = *(struct tmem_oid *)&key; - - (void)zcache_flush_object(LOCAL_CLIENT, pool_id, &oid); -} - -static void zcache_cleancache_flush_fs(int pool_id) -{ - if (pool_id >= 0) - (void)zcache_destroy_pool(pool_id); -} - -static int zcache_cleancache_init_fs(size_t pagesize) -{ - BUG_ON(sizeof(struct cleancache_filekey) != - sizeof(struct tmem_oid)); - BUG_ON(pagesize != PAGE_SIZE); - return zcache_local_new_pool(0); -} - -static int zcache_cleancache_init_shared_fs(char *uuid, size_t pagesize) -{ - /* shared pools are unsupported and map to private */ - BUG_ON(sizeof(struct cleancache_filekey) != - sizeof(struct tmem_oid)); - BUG_ON(pagesize != PAGE_SIZE); - return zcache_local_new_pool(0); -} - -static struct cleancache_ops zcache_cleancache_ops = { - .put_page = zcache_cleancache_put_page, - .get_page = zcache_cleancache_get_page, - .invalidate_page = zcache_cleancache_flush_page, - .invalidate_inode = zcache_cleancache_flush_inode, - .invalidate_fs = zcache_cleancache_flush_fs, - .init_shared_fs = zcache_cleancache_init_shared_fs, - .init_fs = zcache_cleancache_init_fs -}; - -struct cleancache_ops zcache_cleancache_register_ops(void) -{ - struct cleancache_ops old_ops = - cleancache_register_ops(&zcache_cleancache_ops); - - return old_ops; -} -#endif - -#ifdef CONFIG_FRONTSWAP -/* a single tmem poolid is used for all frontswap "types" (swapfiles) */ -static int zcache_frontswap_poolid = -1; - -/* - * Swizzling increases objects per swaptype, increasing tmem concurrency - * for heavy swaploads. Later, larger nr_cpus -> larger SWIZ_BITS - */ -#define SWIZ_BITS 8 -#define SWIZ_MASK ((1 << SWIZ_BITS) - 1) -#define _oswiz(_type, _ind) ((_type << SWIZ_BITS) | (_ind & SWIZ_MASK)) -#define iswiz(_ind) (_ind >> SWIZ_BITS) - -static inline struct tmem_oid oswiz(unsigned type, u32 ind) -{ - struct tmem_oid oid = { .oid = { 0 } }; - oid.oid[0] = _oswiz(type, ind); - return oid; -} - -static int zcache_frontswap_store(unsigned type, pgoff_t offset, - struct page *page) -{ - u64 ind64 = (u64)offset; - u32 ind = (u32)offset; - struct tmem_oid oid = oswiz(type, ind); - int ret = -1; - unsigned long flags; - char *kva; - - BUG_ON(!PageLocked(page)); - if (likely(ind64 == ind)) { - local_irq_save(flags); - kva = page_address(page); - ret = zcache_put(LOCAL_CLIENT, zcache_frontswap_poolid, - &oid, iswiz(ind), kva, PAGE_SIZE, 0, 0); - local_irq_restore(flags); - } - return ret; -} - -/* returns 0 if the page was successfully gotten from frontswap, -1 if - * was not present (should never happen!) */ -static int zcache_frontswap_load(unsigned type, pgoff_t offset, - struct page *page) -{ - u64 ind64 = (u64)offset; - u32 ind = (u32)offset; - struct tmem_oid oid = oswiz(type, ind); - int ret = -1; - - preempt_disable(); /* FIXME, remove this? */ - BUG_ON(!PageLocked(page)); - if (likely(ind64 == ind)) { - char *kva = page_address(page); - size_t size = PAGE_SIZE; - - ret = zcache_get(LOCAL_CLIENT, zcache_frontswap_poolid, - &oid, iswiz(ind), kva, &size, 0, -1); - } - preempt_enable(); /* FIXME, remove this? */ - return ret; -} - -/* flush a single page from frontswap */ -static void zcache_frontswap_flush_page(unsigned type, pgoff_t offset) -{ - u64 ind64 = (u64)offset; - u32 ind = (u32)offset; - struct tmem_oid oid = oswiz(type, ind); - - if (likely(ind64 == ind)) - (void)zcache_flush(LOCAL_CLIENT, zcache_frontswap_poolid, - &oid, iswiz(ind)); -} - -/* flush all pages from the passed swaptype */ -static void zcache_frontswap_flush_area(unsigned type) -{ - struct tmem_oid oid; - int ind; - - for (ind = SWIZ_MASK; ind >= 0; ind--) { - oid = oswiz(type, ind); - (void)zcache_flush_object(LOCAL_CLIENT, - zcache_frontswap_poolid, &oid); - } -} - -static void zcache_frontswap_init(unsigned ignored) -{ - /* a single tmem poolid is used for all frontswap "types" (swapfiles) */ - if (zcache_frontswap_poolid < 0) - zcache_frontswap_poolid = - zcache_local_new_pool(TMEM_POOL_PERSIST); -} - -static struct frontswap_ops zcache_frontswap_ops = { - .store = zcache_frontswap_store, - .load = zcache_frontswap_load, - .invalidate_page = zcache_frontswap_flush_page, - .invalidate_area = zcache_frontswap_flush_area, - .init = zcache_frontswap_init -}; - -struct frontswap_ops zcache_frontswap_register_ops(void) -{ - struct frontswap_ops old_ops = - frontswap_register_ops(&zcache_frontswap_ops); - - return old_ops; -} -#endif - -/* - * frontswap selfshrinking - */ - -#ifdef CONFIG_FRONTSWAP -/* In HZ, controls frequency of worker invocation. */ -static unsigned int selfshrink_interval __read_mostly = 5; - -static void selfshrink_process(struct work_struct *work); -static DECLARE_DELAYED_WORK(selfshrink_worker, selfshrink_process); - -/* Enable/disable with sysfs. */ -static bool frontswap_selfshrinking __read_mostly; - -/* Enable/disable with kernel boot option. */ -static bool use_frontswap_selfshrink __initdata = true; - -/* - * The default values for the following parameters were deemed reasonable - * by experimentation, may be workload-dependent, and can all be - * adjusted via sysfs. - */ - -/* Control rate for frontswap shrinking. Higher hysteresis is slower. */ -static unsigned int frontswap_hysteresis __read_mostly = 20; - -/* - * Number of selfshrink worker invocations to wait before observing that - * frontswap selfshrinking should commence. Note that selfshrinking does - * not use a separate worker thread. - */ -static unsigned int frontswap_inertia __read_mostly = 3; - -/* Countdown to next invocation of frontswap_shrink() */ -static unsigned long frontswap_inertia_counter; - -/* - * Invoked by the selfshrink worker thread, uses current number of pages - * in frontswap (frontswap_curr_pages()), previous status, and control - * values (hysteresis and inertia) to determine if frontswap should be - * shrunk and what the new frontswap size should be. Note that - * frontswap_shrink is essentially a partial swapoff that immediately - * transfers pages from the "swap device" (frontswap) back into kernel - * RAM; despite the name, frontswap "shrinking" is very different from - * the "shrinker" interface used by the kernel MM subsystem to reclaim - * memory. - */ -static void frontswap_selfshrink(void) -{ - static unsigned long cur_frontswap_pages; - static unsigned long last_frontswap_pages; - static unsigned long tgt_frontswap_pages; - - last_frontswap_pages = cur_frontswap_pages; - cur_frontswap_pages = frontswap_curr_pages(); - if (!cur_frontswap_pages || - (cur_frontswap_pages > last_frontswap_pages)) { - frontswap_inertia_counter = frontswap_inertia; - return; - } - if (frontswap_inertia_counter && --frontswap_inertia_counter) - return; - if (cur_frontswap_pages <= frontswap_hysteresis) - tgt_frontswap_pages = 0; - else - tgt_frontswap_pages = cur_frontswap_pages - - (cur_frontswap_pages / frontswap_hysteresis); - frontswap_shrink(tgt_frontswap_pages); -} - -static int __init ramster_nofrontswap_selfshrink_setup(char *s) -{ - use_frontswap_selfshrink = false; - return 1; -} - -__setup("noselfshrink", ramster_nofrontswap_selfshrink_setup); - -static void selfshrink_process(struct work_struct *work) -{ - if (frontswap_selfshrinking && frontswap_enabled) { - frontswap_selfshrink(); - schedule_delayed_work(&selfshrink_worker, - selfshrink_interval * HZ); - } -} - -static int ramster_enabled; - -static int __init ramster_selfshrink_init(void) -{ - frontswap_selfshrinking = ramster_enabled && use_frontswap_selfshrink; - if (frontswap_selfshrinking) - pr_info("ramster: Initializing frontswap " - "selfshrinking driver.\n"); - else - return -ENODEV; - - schedule_delayed_work(&selfshrink_worker, selfshrink_interval * HZ); - - return 0; -} - -subsys_initcall(ramster_selfshrink_init); -#endif - -/* - * zcache initialization - * NOTE FOR NOW ramster MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR - * NOTHING HAPPENS! - */ - -static int ramster_enabled; - -static int __init enable_ramster(char *s) -{ - ramster_enabled = 1; - return 1; -} -__setup("ramster", enable_ramster); - -/* allow independent dynamic disabling of cleancache and frontswap */ - -static int use_cleancache = 1; - -static int __init no_cleancache(char *s) -{ - pr_info("INIT no_cleancache called\n"); - use_cleancache = 0; - return 1; -} - -/* - * FIXME: need to guarantee this gets checked before zcache_init is called - * What is the correct way to achieve this? - */ -early_param("nocleancache", no_cleancache); - -static int use_frontswap = 1; - -static int __init no_frontswap(char *s) -{ - pr_info("INIT no_frontswap called\n"); - use_frontswap = 0; - return 1; -} - -__setup("nofrontswap", no_frontswap); - -static int __init zcache_init(void) -{ - int ret = 0; - -#ifdef CONFIG_SYSFS - ret = sysfs_create_group(mm_kobj, &zcache_attr_group); - ret = sysfs_create_group(mm_kobj, &ramster_attr_group); - if (ret) { - pr_err("ramster: can't create sysfs\n"); - goto out; - } -#endif /* CONFIG_SYSFS */ -#if defined(CONFIG_CLEANCACHE) || defined(CONFIG_FRONTSWAP) - if (ramster_enabled) { - unsigned int cpu; - - (void)r2net_register_handlers(); - tmem_register_hostops(&zcache_hostops); - tmem_register_pamops(&zcache_pamops); - ret = register_cpu_notifier(&zcache_cpu_notifier_block); - if (ret) { - pr_err("ramster: can't register cpu notifier\n"); - goto out; - } - for_each_online_cpu(cpu) { - void *pcpu = (void *)(long)cpu; - zcache_cpu_notifier(&zcache_cpu_notifier_block, - CPU_UP_PREPARE, pcpu); - } - } - zcache_objnode_cache = kmem_cache_create("zcache_objnode", - sizeof(struct tmem_objnode), 0, 0, NULL); - zcache_obj_cache = kmem_cache_create("zcache_obj", - sizeof(struct tmem_obj), 0, 0, NULL); - ramster_flnode_cache = kmem_cache_create("ramster_flnode", - sizeof(struct flushlist_node), 0, 0, NULL); -#endif -#ifdef CONFIG_CLEANCACHE - pr_info("INIT ramster_enabled=%d use_cleancache=%d\n", - ramster_enabled, use_cleancache); - if (ramster_enabled && use_cleancache) { - struct cleancache_ops old_ops; - - zbud_init(); - register_shrinker(&zcache_shrinker); - old_ops = zcache_cleancache_register_ops(); - pr_info("ramster: cleancache enabled using kernel " - "transcendent memory and compression buddies\n"); - if (old_ops.init_fs != NULL) - pr_warning("ramster: cleancache_ops overridden"); - } -#endif -#ifdef CONFIG_FRONTSWAP - pr_info("INIT ramster_enabled=%d use_frontswap=%d\n", - ramster_enabled, use_frontswap); - if (ramster_enabled && use_frontswap) { - struct frontswap_ops old_ops; - - zcache_new_client(LOCAL_CLIENT); - old_ops = zcache_frontswap_register_ops(); - pr_info("ramster: frontswap enabled using kernel " - "transcendent memory and xvmalloc\n"); - if (old_ops.init != NULL) - pr_warning("ramster: frontswap_ops overridden"); - } - if (ramster_enabled && (use_frontswap || use_cleancache)) - ramster_remotify_init(); -#endif -out: - return ret; -} - -module_init(zcache_init) |