From 16a4bfb9e9dfefbd28ee170fa3e259bc88d81eb5 Mon Sep 17 00:00:00 2001 From: Nitin Gupta Date: Tue, 1 Jun 2010 13:31:24 +0530 Subject: Staging: Rename ramzswap files to zram Related changes: - Modify revelant Kconfig and Makefile accordingly. - Change include filenames in code. - Remove dependency on CONFIG_SWAP in Kconfig as zram usage is no longer limited to swap disks. Signed-off-by: Nitin Gupta Acked-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig index d5b827c..cdd3ea3 100644 --- a/drivers/staging/Kconfig +++ b/drivers/staging/Kconfig @@ -119,7 +119,7 @@ source "drivers/staging/sep/Kconfig" source "drivers/staging/iio/Kconfig" -source "drivers/staging/ramzswap/Kconfig" +source "drivers/staging/zram/Kconfig" source "drivers/staging/wlags49_h2/Kconfig" diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile index 2c14f89..beceaff 100644 --- a/drivers/staging/Makefile +++ b/drivers/staging/Makefile @@ -40,7 +40,7 @@ obj-$(CONFIG_RAR_REGISTER) += rar_register/ obj-$(CONFIG_MRST_RAR_HANDLER) += memrar/ obj-$(CONFIG_DX_SEP) += sep/ obj-$(CONFIG_IIO) += iio/ -obj-$(CONFIG_RAMZSWAP) += ramzswap/ +obj-$(CONFIG_ZRAM) += zram/ obj-$(CONFIG_WLAGS49_H2) += wlags49_h2/ obj-$(CONFIG_WLAGS49_H25) += wlags49_h25/ obj-$(CONFIG_BATMAN_ADV) += batman-adv/ diff --git a/drivers/staging/ramzswap/Kconfig b/drivers/staging/ramzswap/Kconfig deleted file mode 100644 index 127b3c6..0000000 --- a/drivers/staging/ramzswap/Kconfig +++ /dev/null @@ -1,21 +0,0 @@ -config RAMZSWAP - tristate "Compressed in-memory swap device (ramzswap)" - depends on SWAP - select LZO_COMPRESS - select LZO_DECOMPRESS - default n - help - Creates virtual block devices which can (only) be used as swap - disks. Pages swapped to these disks are compressed and stored in - memory itself. - - See ramzswap.txt for more information. - Project home: http://compcache.googlecode.com/ - -config RAMZSWAP_STATS - bool "Enable ramzswap stats" - depends on RAMZSWAP - default y - help - Enable statistics collection for ramzswap. This adds only a minimal - overhead. In unsure, say Y. diff --git a/drivers/staging/ramzswap/Makefile b/drivers/staging/ramzswap/Makefile deleted file mode 100644 index 507d7dc..0000000 --- a/drivers/staging/ramzswap/Makefile +++ /dev/null @@ -1,3 +0,0 @@ -ramzswap-objs := ramzswap_drv.o xvmalloc.o - -obj-$(CONFIG_RAMZSWAP) += ramzswap.o diff --git a/drivers/staging/ramzswap/ramzswap.txt b/drivers/staging/ramzswap/ramzswap.txt deleted file mode 100644 index 9694acf..0000000 --- a/drivers/staging/ramzswap/ramzswap.txt +++ /dev/null @@ -1,51 +0,0 @@ -ramzswap: Compressed RAM based swap device -------------------------------------------- - -Project home: http://compcache.googlecode.com/ - -* Introduction - -The ramzswap module creates RAM based block devices which can (only) be used as -swap disks. Pages swapped to these devices are compressed and stored in memory -itself. See project home for use cases, performance numbers and a lot more. - -Individual ramzswap devices are configured and initialized using rzscontrol -userspace utility as shown in examples below. See rzscontrol man page for more -details. - -* Usage - -Following shows a typical sequence of steps for using ramzswap. - -1) Load Modules: - modprobe ramzswap num_devices=4 - This creates 4 (uninitialized) devices: /dev/ramzswap{0,1,2,3} - (num_devices parameter is optional. Default: 1) - -2) Initialize: - Use rzscontrol utility to configure and initialize individual - ramzswap devices. Example: - rzscontrol /dev/ramzswap2 --init # uses default value of disksize_kb - - *See rzscontrol man page for more details and examples* - -3) Activate: - swapon /dev/ramzswap2 # or any other initialized ramzswap device - -4) Stats: - rzscontrol /dev/ramzswap2 --stats - -5) Deactivate: - swapoff /dev/ramzswap2 - -6) Reset: - rzscontrol /dev/ramzswap2 --reset - (This frees all the memory allocated for this device). - - -Please report any problems at: - - Mailing list: linux-mm-cc at laptop dot org - - Issue tracker: http://code.google.com/p/compcache/issues/list - -Nitin Gupta -ngupta@vflare.org diff --git a/drivers/staging/ramzswap/ramzswap_drv.c b/drivers/staging/ramzswap/ramzswap_drv.c deleted file mode 100644 index 7b5cc61..0000000 --- a/drivers/staging/ramzswap/ramzswap_drv.c +++ /dev/null @@ -1,805 +0,0 @@ -/* - * Compressed RAM based swap device - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - * - * Project home: http://compcache.googlecode.com - */ - -#define KMSG_COMPONENT "ramzswap" -#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "ramzswap_drv.h" - -/* Globals */ -static int ramzswap_major; -static struct ramzswap *devices; - -/* Module params (documentation at end) */ -static unsigned int num_devices; - -static int rzs_test_flag(struct ramzswap *rzs, u32 index, - enum rzs_pageflags flag) -{ - return rzs->table[index].flags & BIT(flag); -} - -static void rzs_set_flag(struct ramzswap *rzs, u32 index, - enum rzs_pageflags flag) -{ - rzs->table[index].flags |= BIT(flag); -} - -static void rzs_clear_flag(struct ramzswap *rzs, u32 index, - enum rzs_pageflags flag) -{ - rzs->table[index].flags &= ~BIT(flag); -} - -static int page_zero_filled(void *ptr) -{ - unsigned int pos; - unsigned long *page; - - page = (unsigned long *)ptr; - - for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { - if (page[pos]) - return 0; - } - - return 1; -} - -static void ramzswap_set_disksize(struct ramzswap *rzs, size_t totalram_bytes) -{ - if (!rzs->disksize) { - pr_info( - "disk size not provided. You can use disksize_kb module " - "param to specify size.\nUsing default: (%u%% of RAM).\n", - default_disksize_perc_ram - ); - rzs->disksize = default_disksize_perc_ram * - (totalram_bytes / 100); - } - - if (rzs->disksize > 2 * (totalram_bytes)) { - pr_info( - "There is little point creating a ramzswap of greater than " - "twice the size of memory since we expect a 2:1 compression " - "ratio. Note that ramzswap uses about 0.1%% of the size of " - "the swap device when not in use so a huge ramzswap is " - "wasteful.\n" - "\tMemory Size: %zu kB\n" - "\tSize you selected: %zu kB\n" - "Continuing anyway ...\n", - totalram_bytes >> 10, rzs->disksize - ); - } - - rzs->disksize &= PAGE_MASK; -} - -static void ramzswap_ioctl_get_stats(struct ramzswap *rzs, - struct ramzswap_ioctl_stats *s) -{ - s->disksize = rzs->disksize; - -#if defined(CONFIG_RAMZSWAP_STATS) - { - struct ramzswap_stats *rs = &rzs->stats; - size_t succ_writes, mem_used; - unsigned int good_compress_perc = 0, no_compress_perc = 0; - - mem_used = xv_get_total_size_bytes(rzs->mem_pool) - + (rs->pages_expand << PAGE_SHIFT); - succ_writes = rzs_stat64_read(rzs, &rs->num_writes) - - rzs_stat64_read(rzs, &rs->failed_writes); - - if (succ_writes && rs->pages_stored) { - good_compress_perc = rs->good_compress * 100 - / rs->pages_stored; - no_compress_perc = rs->pages_expand * 100 - / rs->pages_stored; - } - - s->num_reads = rzs_stat64_read(rzs, &rs->num_reads); - s->num_writes = rzs_stat64_read(rzs, &rs->num_writes); - s->failed_reads = rzs_stat64_read(rzs, &rs->failed_reads); - s->failed_writes = rzs_stat64_read(rzs, &rs->failed_writes); - s->invalid_io = rzs_stat64_read(rzs, &rs->invalid_io); - s->notify_free = rzs_stat64_read(rzs, &rs->notify_free); - s->pages_zero = rs->pages_zero; - - s->good_compress_pct = good_compress_perc; - s->pages_expand_pct = no_compress_perc; - - s->pages_stored = rs->pages_stored; - s->pages_used = mem_used >> PAGE_SHIFT; - s->orig_data_size = rs->pages_stored << PAGE_SHIFT; - s->compr_data_size = rs->compr_size; - s->mem_used_total = mem_used; - } -#endif /* CONFIG_RAMZSWAP_STATS */ -} - -static void ramzswap_free_page(struct ramzswap *rzs, size_t index) -{ - u32 clen; - void *obj; - - struct page *page = rzs->table[index].page; - u32 offset = rzs->table[index].offset; - - if (unlikely(!page)) { - /* - * No memory is allocated for zero filled pages. - * Simply clear zero page flag. - */ - if (rzs_test_flag(rzs, index, RZS_ZERO)) { - rzs_clear_flag(rzs, index, RZS_ZERO); - rzs_stat_dec(&rzs->stats.pages_zero); - } - return; - } - - if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) { - clen = PAGE_SIZE; - __free_page(page); - rzs_clear_flag(rzs, index, RZS_UNCOMPRESSED); - rzs_stat_dec(&rzs->stats.pages_expand); - goto out; - } - - obj = kmap_atomic(page, KM_USER0) + offset; - clen = xv_get_object_size(obj) - sizeof(struct zobj_header); - kunmap_atomic(obj, KM_USER0); - - xv_free(rzs->mem_pool, page, offset); - if (clen <= PAGE_SIZE / 2) - rzs_stat_dec(&rzs->stats.good_compress); - -out: - rzs->stats.compr_size -= clen; - rzs_stat_dec(&rzs->stats.pages_stored); - - rzs->table[index].page = NULL; - rzs->table[index].offset = 0; -} - -static void handle_zero_page(struct page *page) -{ - void *user_mem; - - user_mem = kmap_atomic(page, KM_USER0); - memset(user_mem, 0, PAGE_SIZE); - kunmap_atomic(user_mem, KM_USER0); - - flush_dcache_page(page); -} - -static void handle_uncompressed_page(struct ramzswap *rzs, - struct page *page, u32 index) -{ - unsigned char *user_mem, *cmem; - - user_mem = kmap_atomic(page, KM_USER0); - cmem = kmap_atomic(rzs->table[index].page, KM_USER1) + - rzs->table[index].offset; - - memcpy(user_mem, cmem, PAGE_SIZE); - kunmap_atomic(user_mem, KM_USER0); - kunmap_atomic(cmem, KM_USER1); - - flush_dcache_page(page); -} - -static int ramzswap_read(struct ramzswap *rzs, struct bio *bio) -{ - - int i; - u32 index; - struct bio_vec *bvec; - - rzs_stat64_inc(rzs, &rzs->stats.num_reads); - - index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; - bio_for_each_segment(bvec, bio, i) { - int ret; - size_t clen; - struct page *page; - struct zobj_header *zheader; - unsigned char *user_mem, *cmem; - - page = bvec->bv_page; - - if (rzs_test_flag(rzs, index, RZS_ZERO)) { - handle_zero_page(page); - continue; - } - - /* Requested page is not present in compressed area */ - if (unlikely(!rzs->table[index].page)) { - pr_debug("Read before write: sector=%lu, size=%u", - (ulong)(bio->bi_sector), bio->bi_size); - /* Do nothing */ - continue; - } - - /* Page is stored uncompressed since it's incompressible */ - if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) { - handle_uncompressed_page(rzs, page, index); - continue; - } - - user_mem = kmap_atomic(page, KM_USER0); - clen = PAGE_SIZE; - - cmem = kmap_atomic(rzs->table[index].page, KM_USER1) + - rzs->table[index].offset; - - ret = lzo1x_decompress_safe( - cmem + sizeof(*zheader), - xv_get_object_size(cmem) - sizeof(*zheader), - user_mem, &clen); - - kunmap_atomic(user_mem, KM_USER0); - kunmap_atomic(cmem, KM_USER1); - - /* Should NEVER happen. Return bio error if it does. */ - if (unlikely(ret != LZO_E_OK)) { - pr_err("Decompression failed! err=%d, page=%u\n", - ret, index); - rzs_stat64_inc(rzs, &rzs->stats.failed_reads); - goto out; - } - - flush_dcache_page(page); - index++; - } - - set_bit(BIO_UPTODATE, &bio->bi_flags); - bio_endio(bio, 0); - return 0; - -out: - bio_io_error(bio); - return 0; -} - -static int ramzswap_write(struct ramzswap *rzs, struct bio *bio) -{ - int i; - u32 index; - struct bio_vec *bvec; - - rzs_stat64_inc(rzs, &rzs->stats.num_writes); - - index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; - - bio_for_each_segment(bvec, bio, i) { - int ret; - u32 offset; - size_t clen; - struct zobj_header *zheader; - struct page *page, *page_store; - unsigned char *user_mem, *cmem, *src; - - page = bvec->bv_page; - src = rzs->compress_buffer; - - /* - * System overwrites unused sectors. Free memory associated - * with this sector now. - */ - if (rzs->table[index].page || - rzs_test_flag(rzs, index, RZS_ZERO)) - ramzswap_free_page(rzs, index); - - mutex_lock(&rzs->lock); - - user_mem = kmap_atomic(page, KM_USER0); - if (page_zero_filled(user_mem)) { - kunmap_atomic(user_mem, KM_USER0); - mutex_unlock(&rzs->lock); - rzs_stat_inc(&rzs->stats.pages_zero); - rzs_set_flag(rzs, index, RZS_ZERO); - continue; - } - - ret = lzo1x_1_compress(user_mem, PAGE_SIZE, src, &clen, - rzs->compress_workmem); - - kunmap_atomic(user_mem, KM_USER0); - - if (unlikely(ret != LZO_E_OK)) { - mutex_unlock(&rzs->lock); - pr_err("Compression failed! err=%d\n", ret); - rzs_stat64_inc(rzs, &rzs->stats.failed_writes); - goto out; - } - - /* - * Page is incompressible. Store it as-is (uncompressed) - * since we do not want to return too many swap write - * errors which has side effect of hanging the system. - */ - if (unlikely(clen > max_zpage_size)) { - clen = PAGE_SIZE; - page_store = alloc_page(GFP_NOIO | __GFP_HIGHMEM); - if (unlikely(!page_store)) { - mutex_unlock(&rzs->lock); - pr_info("Error allocating memory for " - "incompressible page: %u\n", index); - rzs_stat64_inc(rzs, &rzs->stats.failed_writes); - goto out; - } - - offset = 0; - rzs_set_flag(rzs, index, RZS_UNCOMPRESSED); - rzs_stat_inc(&rzs->stats.pages_expand); - rzs->table[index].page = page_store; - src = kmap_atomic(page, KM_USER0); - goto memstore; - } - - if (xv_malloc(rzs->mem_pool, clen + sizeof(*zheader), - &rzs->table[index].page, &offset, - GFP_NOIO | __GFP_HIGHMEM)) { - mutex_unlock(&rzs->lock); - pr_info("Error allocating memory for compressed " - "page: %u, size=%zu\n", index, clen); - rzs_stat64_inc(rzs, &rzs->stats.failed_writes); - goto out; - } - -memstore: - rzs->table[index].offset = offset; - - cmem = kmap_atomic(rzs->table[index].page, KM_USER1) + - rzs->table[index].offset; - -#if 0 - /* Back-reference needed for memory defragmentation */ - if (!rzs_test_flag(rzs, index, RZS_UNCOMPRESSED)) { - zheader = (struct zobj_header *)cmem; - zheader->table_idx = index; - cmem += sizeof(*zheader); - } -#endif - - memcpy(cmem, src, clen); - - kunmap_atomic(cmem, KM_USER1); - if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) - kunmap_atomic(src, KM_USER0); - - /* Update stats */ - rzs->stats.compr_size += clen; - rzs_stat_inc(&rzs->stats.pages_stored); - if (clen <= PAGE_SIZE / 2) - rzs_stat_inc(&rzs->stats.good_compress); - - mutex_unlock(&rzs->lock); - index++; - } - - set_bit(BIO_UPTODATE, &bio->bi_flags); - bio_endio(bio, 0); - return 0; - -out: - bio_io_error(bio); - return 0; -} - -/* - * Check if request is within bounds and page aligned. - */ -static inline int valid_io_request(struct ramzswap *rzs, struct bio *bio) -{ - if (unlikely( - (bio->bi_sector >= (rzs->disksize >> SECTOR_SHIFT)) || - (bio->bi_sector & (SECTORS_PER_PAGE - 1)) || - (bio->bi_size & (PAGE_SIZE - 1)))) { - - return 0; - } - - /* I/O request is valid */ - return 1; -} - -/* - * Handler function for all ramzswap I/O requests. - */ -static int ramzswap_make_request(struct request_queue *queue, struct bio *bio) -{ - int ret = 0; - struct ramzswap *rzs = queue->queuedata; - - if (unlikely(!rzs->init_done)) { - bio_io_error(bio); - return 0; - } - - if (!valid_io_request(rzs, bio)) { - rzs_stat64_inc(rzs, &rzs->stats.invalid_io); - bio_io_error(bio); - return 0; - } - - switch (bio_data_dir(bio)) { - case READ: - ret = ramzswap_read(rzs, bio); - break; - - case WRITE: - ret = ramzswap_write(rzs, bio); - break; - } - - return ret; -} - -static void reset_device(struct ramzswap *rzs) -{ - size_t index; - - /* Do not accept any new I/O request */ - rzs->init_done = 0; - - /* Free various per-device buffers */ - kfree(rzs->compress_workmem); - free_pages((unsigned long)rzs->compress_buffer, 1); - - rzs->compress_workmem = NULL; - rzs->compress_buffer = NULL; - - /* Free all pages that are still in this ramzswap device */ - for (index = 0; index < rzs->disksize >> PAGE_SHIFT; index++) { - struct page *page; - u16 offset; - - page = rzs->table[index].page; - offset = rzs->table[index].offset; - - if (!page) - continue; - - if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) - __free_page(page); - else - xv_free(rzs->mem_pool, page, offset); - } - - vfree(rzs->table); - rzs->table = NULL; - - xv_destroy_pool(rzs->mem_pool); - rzs->mem_pool = NULL; - - /* Reset stats */ - memset(&rzs->stats, 0, sizeof(rzs->stats)); - - rzs->disksize = 0; -} - -static int ramzswap_ioctl_init_device(struct ramzswap *rzs) -{ - int ret; - size_t num_pages; - - if (rzs->init_done) { - pr_info("Device already initialized!\n"); - return -EBUSY; - } - - ramzswap_set_disksize(rzs, totalram_pages << PAGE_SHIFT); - - rzs->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); - if (!rzs->compress_workmem) { - pr_err("Error allocating compressor working memory!\n"); - ret = -ENOMEM; - goto fail; - } - - rzs->compress_buffer = (void *)__get_free_pages(__GFP_ZERO, 1); - if (!rzs->compress_buffer) { - pr_err("Error allocating compressor buffer space\n"); - ret = -ENOMEM; - goto fail; - } - - num_pages = rzs->disksize >> PAGE_SHIFT; - rzs->table = vmalloc(num_pages * sizeof(*rzs->table)); - if (!rzs->table) { - pr_err("Error allocating ramzswap address table\n"); - /* To prevent accessing table entries during cleanup */ - rzs->disksize = 0; - ret = -ENOMEM; - goto fail; - } - memset(rzs->table, 0, num_pages * sizeof(*rzs->table)); - - set_capacity(rzs->disk, rzs->disksize >> SECTOR_SHIFT); - - /* ramzswap devices sort of resembles non-rotational disks */ - queue_flag_set_unlocked(QUEUE_FLAG_NONROT, rzs->disk->queue); - - rzs->mem_pool = xv_create_pool(); - if (!rzs->mem_pool) { - pr_err("Error creating memory pool\n"); - ret = -ENOMEM; - goto fail; - } - - rzs->init_done = 1; - - pr_debug("Initialization done!\n"); - return 0; - -fail: - reset_device(rzs); - - pr_err("Initialization failed: err=%d\n", ret); - return ret; -} - -static int ramzswap_ioctl_reset_device(struct ramzswap *rzs) -{ - if (rzs->init_done) - reset_device(rzs); - - return 0; -} - -static int ramzswap_ioctl(struct block_device *bdev, fmode_t mode, - unsigned int cmd, unsigned long arg) -{ - int ret = 0; - size_t disksize_kb; - - struct ramzswap *rzs = bdev->bd_disk->private_data; - - switch (cmd) { - case RZSIO_SET_DISKSIZE_KB: - if (rzs->init_done) { - ret = -EBUSY; - goto out; - } - if (copy_from_user(&disksize_kb, (void *)arg, - _IOC_SIZE(cmd))) { - ret = -EFAULT; - goto out; - } - rzs->disksize = disksize_kb << 10; - pr_info("Disk size set to %zu kB\n", disksize_kb); - break; - - case RZSIO_GET_STATS: - { - struct ramzswap_ioctl_stats *stats; - if (!rzs->init_done) { - ret = -ENOTTY; - goto out; - } - stats = kzalloc(sizeof(*stats), GFP_KERNEL); - if (!stats) { - ret = -ENOMEM; - goto out; - } - ramzswap_ioctl_get_stats(rzs, stats); - if (copy_to_user((void *)arg, stats, sizeof(*stats))) { - kfree(stats); - ret = -EFAULT; - goto out; - } - kfree(stats); - break; - } - case RZSIO_INIT: - ret = ramzswap_ioctl_init_device(rzs); - break; - - case RZSIO_RESET: - /* Do not reset an active device! */ - if (bdev->bd_holders) { - ret = -EBUSY; - goto out; - } - - /* Make sure all pending I/O is finished */ - if (bdev) - fsync_bdev(bdev); - - ret = ramzswap_ioctl_reset_device(rzs); - break; - - default: - pr_info("Invalid ioctl %u\n", cmd); - ret = -ENOTTY; - } - -out: - return ret; -} - -void ramzswap_slot_free_notify(struct block_device *bdev, unsigned long index) -{ - struct ramzswap *rzs; - - rzs = bdev->bd_disk->private_data; - ramzswap_free_page(rzs, index); - rzs_stat64_inc(rzs, &rzs->stats.notify_free); -} - -static const struct block_device_operations ramzswap_devops = { - .ioctl = ramzswap_ioctl, - .swap_slot_free_notify = ramzswap_slot_free_notify, - .owner = THIS_MODULE -}; - -static int create_device(struct ramzswap *rzs, int device_id) -{ - int ret = 0; - - mutex_init(&rzs->lock); - spin_lock_init(&rzs->stat64_lock); - - rzs->queue = blk_alloc_queue(GFP_KERNEL); - if (!rzs->queue) { - pr_err("Error allocating disk queue for device %d\n", - device_id); - ret = -ENOMEM; - goto out; - } - - blk_queue_make_request(rzs->queue, ramzswap_make_request); - rzs->queue->queuedata = rzs; - - /* gendisk structure */ - rzs->disk = alloc_disk(1); - if (!rzs->disk) { - blk_cleanup_queue(rzs->queue); - pr_warning("Error allocating disk structure for device %d\n", - device_id); - ret = -ENOMEM; - goto out; - } - - rzs->disk->major = ramzswap_major; - rzs->disk->first_minor = device_id; - rzs->disk->fops = &ramzswap_devops; - rzs->disk->queue = rzs->queue; - rzs->disk->private_data = rzs; - snprintf(rzs->disk->disk_name, 16, "ramzswap%d", device_id); - - /* Actual capacity set using RZSIO_SET_DISKSIZE_KB ioctl */ - set_capacity(rzs->disk, 0); - - /* - * To ensure that we always get PAGE_SIZE aligned - * and n*PAGE_SIZED sized I/O requests. - */ - blk_queue_physical_block_size(rzs->disk->queue, PAGE_SIZE); - blk_queue_logical_block_size(rzs->disk->queue, PAGE_SIZE); - blk_queue_io_min(rzs->disk->queue, PAGE_SIZE); - blk_queue_io_opt(rzs->disk->queue, PAGE_SIZE); - - add_disk(rzs->disk); - - rzs->init_done = 0; - -out: - return ret; -} - -static void destroy_device(struct ramzswap *rzs) -{ - if (rzs->disk) { - del_gendisk(rzs->disk); - put_disk(rzs->disk); - } - - if (rzs->queue) - blk_cleanup_queue(rzs->queue); -} - -static int __init ramzswap_init(void) -{ - int ret, dev_id; - - if (num_devices > max_num_devices) { - pr_warning("Invalid value for num_devices: %u\n", - num_devices); - ret = -EINVAL; - goto out; - } - - ramzswap_major = register_blkdev(0, "ramzswap"); - if (ramzswap_major <= 0) { - pr_warning("Unable to get major number\n"); - ret = -EBUSY; - goto out; - } - - if (!num_devices) { - pr_info("num_devices not specified. Using default: 1\n"); - num_devices = 1; - } - - /* Allocate the device array and initialize each one */ - pr_info("Creating %u devices ...\n", num_devices); - devices = kzalloc(num_devices * sizeof(struct ramzswap), GFP_KERNEL); - if (!devices) { - ret = -ENOMEM; - goto unregister; - } - - for (dev_id = 0; dev_id < num_devices; dev_id++) { - ret = create_device(&devices[dev_id], dev_id); - if (ret) - goto free_devices; - } - - return 0; - -free_devices: - while (dev_id) - destroy_device(&devices[--dev_id]); -unregister: - unregister_blkdev(ramzswap_major, "ramzswap"); -out: - return ret; -} - -static void __exit ramzswap_exit(void) -{ - int i; - struct ramzswap *rzs; - - for (i = 0; i < num_devices; i++) { - rzs = &devices[i]; - - destroy_device(rzs); - if (rzs->init_done) - reset_device(rzs); - } - - unregister_blkdev(ramzswap_major, "ramzswap"); - - kfree(devices); - pr_debug("Cleanup done!\n"); -} - -module_param(num_devices, uint, 0); -MODULE_PARM_DESC(num_devices, "Number of ramzswap devices"); - -module_init(ramzswap_init); -module_exit(ramzswap_exit); - -MODULE_LICENSE("Dual BSD/GPL"); -MODULE_AUTHOR("Nitin Gupta "); -MODULE_DESCRIPTION("Compressed RAM Based Swap Device"); diff --git a/drivers/staging/ramzswap/ramzswap_drv.h b/drivers/staging/ramzswap/ramzswap_drv.h deleted file mode 100644 index ad91726..0000000 --- a/drivers/staging/ramzswap/ramzswap_drv.h +++ /dev/null @@ -1,168 +0,0 @@ -/* - * Compressed RAM based swap device - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - * - * Project home: http://compcache.googlecode.com - */ - -#ifndef _RAMZSWAP_DRV_H_ -#define _RAMZSWAP_DRV_H_ - -#include -#include - -#include "ramzswap_ioctl.h" -#include "xvmalloc.h" - -/* - * Some arbitrary value. This is just to catch - * invalid value for num_devices module parameter. - */ -static const unsigned max_num_devices = 32; - -/* - * Stored at beginning of each compressed object. - * - * It stores back-reference to table entry which points to this - * object. This is required to support memory defragmentation. - */ -struct zobj_header { -#if 0 - u32 table_idx; -#endif -}; - -/*-- Configurable parameters */ - -/* Default ramzswap disk size: 25% of total RAM */ -static const unsigned default_disksize_perc_ram = 25; - -/* - * Pages that compress to size greater than this are stored - * uncompressed in memory. - */ -static const unsigned max_zpage_size = PAGE_SIZE / 4 * 3; - -/* - * NOTE: max_zpage_size must be less than or equal to: - * XV_MAX_ALLOC_SIZE - sizeof(struct zobj_header) - * otherwise, xv_malloc() would always return failure. - */ - -/*-- End of configurable params */ - -#define SECTOR_SHIFT 9 -#define SECTOR_SIZE (1 << SECTOR_SHIFT) -#define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) -#define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) - -/* Flags for ramzswap pages (table[page_no].flags) */ -enum rzs_pageflags { - /* Page is stored uncompressed */ - RZS_UNCOMPRESSED, - - /* Page consists entirely of zeros */ - RZS_ZERO, - - __NR_RZS_PAGEFLAGS, -}; - -/*-- Data structures */ - -/* - * Allocated for each swap slot, indexed by page no. - * These table entries must fit exactly in a page. - */ -struct table { - struct page *page; - u16 offset; - u8 count; /* object ref count (not yet used) */ - u8 flags; -} __attribute__((aligned(4))); - -struct ramzswap_stats { - /* basic stats */ - size_t compr_size; /* compressed size of pages stored - - * needed to enforce memlimit */ - /* more stats */ -#if defined(CONFIG_RAMZSWAP_STATS) - u64 num_reads; /* failed + successful */ - u64 num_writes; /* --do-- */ - u64 failed_reads; /* should NEVER! happen */ - u64 failed_writes; /* can happen when memory is too low */ - u64 invalid_io; /* non-swap I/O requests */ - u64 notify_free; /* no. of swap slot free notifications */ - u32 pages_zero; /* no. of zero filled pages */ - u32 pages_stored; /* no. of pages currently stored */ - u32 good_compress; /* % of pages with compression ratio<=50% */ - u32 pages_expand; /* % of incompressible pages */ -#endif -}; - -struct ramzswap { - struct xv_pool *mem_pool; - void *compress_workmem; - void *compress_buffer; - struct table *table; - spinlock_t stat64_lock; /* protect 64-bit stats */ - struct mutex lock; /* protect compression buffers against - * concurrent writes */ - struct request_queue *queue; - struct gendisk *disk; - int init_done; - /* - * This is limit on amount of *uncompressed* worth of data - * we can hold. When backing swap device is provided, it is - * set equal to device size. - */ - size_t disksize; /* bytes */ - - struct ramzswap_stats stats; -}; - -/*-- */ - -/* Debugging and Stats */ -#if defined(CONFIG_RAMZSWAP_STATS) -static void rzs_stat_inc(u32 *v) -{ - *v = *v + 1; -} - -static void rzs_stat_dec(u32 *v) -{ - *v = *v - 1; -} - -static void rzs_stat64_inc(struct ramzswap *rzs, u64 *v) -{ - spin_lock(&rzs->stat64_lock); - *v = *v + 1; - spin_unlock(&rzs->stat64_lock); -} - -static u64 rzs_stat64_read(struct ramzswap *rzs, u64 *v) -{ - u64 val; - - spin_lock(&rzs->stat64_lock); - val = *v; - spin_unlock(&rzs->stat64_lock); - - return val; -} -#else -#define rzs_stat_inc(v) -#define rzs_stat_dec(v) -#define rzs_stat64_inc(r, v) -#define rzs_stat64_read(r, v) -#endif /* CONFIG_RAMZSWAP_STATS */ - -#endif diff --git a/drivers/staging/ramzswap/ramzswap_ioctl.h b/drivers/staging/ramzswap/ramzswap_ioctl.h deleted file mode 100644 index db94bcb..0000000 --- a/drivers/staging/ramzswap/ramzswap_ioctl.h +++ /dev/null @@ -1,42 +0,0 @@ -/* - * Compressed RAM based swap device - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - * - * Project home: http://compcache.googlecode.com - */ - -#ifndef _RAMZSWAP_IOCTL_H_ -#define _RAMZSWAP_IOCTL_H_ - -struct ramzswap_ioctl_stats { - u64 disksize; /* user specified or equal to backing swap - * size (if present) */ - u64 num_reads; /* failed + successful */ - u64 num_writes; /* --do-- */ - u64 failed_reads; /* should NEVER! happen */ - u64 failed_writes; /* can happen when memory is too low */ - u64 invalid_io; /* non-swap I/O requests */ - u64 notify_free; /* no. of swap slot free notifications */ - u32 pages_zero; /* no. of zero filled pages */ - u32 good_compress_pct; /* no. of pages with compression ratio<=50% */ - u32 pages_expand_pct; /* no. of incompressible pages */ - u32 pages_stored; - u32 pages_used; - u64 orig_data_size; - u64 compr_data_size; - u64 mem_used_total; -} __attribute__ ((packed, aligned(4))); - -#define RZSIO_SET_DISKSIZE_KB _IOW('z', 0, size_t) -#define RZSIO_GET_STATS _IOR('z', 1, struct ramzswap_ioctl_stats) -#define RZSIO_INIT _IO('z', 2) -#define RZSIO_RESET _IO('z', 3) - -#endif diff --git a/drivers/staging/ramzswap/xvmalloc.c b/drivers/staging/ramzswap/xvmalloc.c deleted file mode 100644 index 3fdbb8a..0000000 --- a/drivers/staging/ramzswap/xvmalloc.c +++ /dev/null @@ -1,507 +0,0 @@ -/* - * xvmalloc memory allocator - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - */ - -#include -#include -#include -#include -#include -#include - -#include "xvmalloc.h" -#include "xvmalloc_int.h" - -static void stat_inc(u64 *value) -{ - *value = *value + 1; -} - -static void stat_dec(u64 *value) -{ - *value = *value - 1; -} - -static int test_flag(struct block_header *block, enum blockflags flag) -{ - return block->prev & BIT(flag); -} - -static void set_flag(struct block_header *block, enum blockflags flag) -{ - block->prev |= BIT(flag); -} - -static void clear_flag(struct block_header *block, enum blockflags flag) -{ - block->prev &= ~BIT(flag); -} - -/* - * Given pair, provide a derefrencable pointer. - * This is called from xv_malloc/xv_free path, so it - * needs to be fast. - */ -static void *get_ptr_atomic(struct page *page, u16 offset, enum km_type type) -{ - unsigned char *base; - - base = kmap_atomic(page, type); - return base + offset; -} - -static void put_ptr_atomic(void *ptr, enum km_type type) -{ - kunmap_atomic(ptr, type); -} - -static u32 get_blockprev(struct block_header *block) -{ - return block->prev & PREV_MASK; -} - -static void set_blockprev(struct block_header *block, u16 new_offset) -{ - block->prev = new_offset | (block->prev & FLAGS_MASK); -} - -static struct block_header *BLOCK_NEXT(struct block_header *block) -{ - return (struct block_header *) - ((char *)block + block->size + XV_ALIGN); -} - -/* - * Get index of free list containing blocks of maximum size - * which is less than or equal to given size. - */ -static u32 get_index_for_insert(u32 size) -{ - if (unlikely(size > XV_MAX_ALLOC_SIZE)) - size = XV_MAX_ALLOC_SIZE; - size &= ~FL_DELTA_MASK; - return (size - XV_MIN_ALLOC_SIZE) >> FL_DELTA_SHIFT; -} - -/* - * Get index of free list having blocks of size greater than - * or equal to requested size. - */ -static u32 get_index(u32 size) -{ - if (unlikely(size < XV_MIN_ALLOC_SIZE)) - size = XV_MIN_ALLOC_SIZE; - size = ALIGN(size, FL_DELTA); - return (size - XV_MIN_ALLOC_SIZE) >> FL_DELTA_SHIFT; -} - -/** - * find_block - find block of at least given size - * @pool: memory pool to search from - * @size: size of block required - * @page: page containing required block - * @offset: offset within the page where block is located. - * - * Searches two level bitmap to locate block of at least - * the given size. If such a block is found, it provides - * to identify this block and returns index - * in freelist where we found this block. - * Otherwise, returns 0 and params are not touched. - */ -static u32 find_block(struct xv_pool *pool, u32 size, - struct page **page, u32 *offset) -{ - ulong flbitmap, slbitmap; - u32 flindex, slindex, slbitstart; - - /* There are no free blocks in this pool */ - if (!pool->flbitmap) - return 0; - - /* Get freelist index correspoding to this size */ - slindex = get_index(size); - slbitmap = pool->slbitmap[slindex / BITS_PER_LONG]; - slbitstart = slindex % BITS_PER_LONG; - - /* - * If freelist is not empty at this index, we found the - * block - head of this list. This is approximate best-fit match. - */ - if (test_bit(slbitstart, &slbitmap)) { - *page = pool->freelist[slindex].page; - *offset = pool->freelist[slindex].offset; - return slindex; - } - - /* - * No best-fit found. Search a bit further in bitmap for a free block. - * Second level bitmap consists of series of 32-bit chunks. Search - * further in the chunk where we expected a best-fit, starting from - * index location found above. - */ - slbitstart++; - slbitmap >>= slbitstart; - - /* Skip this search if we were already at end of this bitmap chunk */ - if ((slbitstart != BITS_PER_LONG) && slbitmap) { - slindex += __ffs(slbitmap) + 1; - *page = pool->freelist[slindex].page; - *offset = pool->freelist[slindex].offset; - return slindex; - } - - /* Now do a full two-level bitmap search to find next nearest fit */ - flindex = slindex / BITS_PER_LONG; - - flbitmap = (pool->flbitmap) >> (flindex + 1); - if (!flbitmap) - return 0; - - flindex += __ffs(flbitmap) + 1; - slbitmap = pool->slbitmap[flindex]; - slindex = (flindex * BITS_PER_LONG) + __ffs(slbitmap); - *page = pool->freelist[slindex].page; - *offset = pool->freelist[slindex].offset; - - return slindex; -} - -/* - * Insert block at in freelist of given pool. - * freelist used depends on block size. - */ -static void insert_block(struct xv_pool *pool, struct page *page, u32 offset, - struct block_header *block) -{ - u32 flindex, slindex; - struct block_header *nextblock; - - slindex = get_index_for_insert(block->size); - flindex = slindex / BITS_PER_LONG; - - block->link.prev_page = 0; - block->link.prev_offset = 0; - block->link.next_page = pool->freelist[slindex].page; - block->link.next_offset = pool->freelist[slindex].offset; - pool->freelist[slindex].page = page; - pool->freelist[slindex].offset = offset; - - if (block->link.next_page) { - nextblock = get_ptr_atomic(block->link.next_page, - block->link.next_offset, KM_USER1); - nextblock->link.prev_page = page; - nextblock->link.prev_offset = offset; - put_ptr_atomic(nextblock, KM_USER1); - } - - __set_bit(slindex % BITS_PER_LONG, &pool->slbitmap[flindex]); - __set_bit(flindex, &pool->flbitmap); -} - -/* - * Remove block from head of freelist. Index 'slindex' identifies the freelist. - */ -static void remove_block_head(struct xv_pool *pool, - struct block_header *block, u32 slindex) -{ - struct block_header *tmpblock; - u32 flindex = slindex / BITS_PER_LONG; - - pool->freelist[slindex].page = block->link.next_page; - pool->freelist[slindex].offset = block->link.next_offset; - block->link.prev_page = 0; - block->link.prev_offset = 0; - - if (!pool->freelist[slindex].page) { - __clear_bit(slindex % BITS_PER_LONG, &pool->slbitmap[flindex]); - if (!pool->slbitmap[flindex]) - __clear_bit(flindex, &pool->flbitmap); - } else { - /* - * DEBUG ONLY: We need not reinitialize freelist head previous - * pointer to 0 - we never depend on its value. But just for - * sanity, lets do it. - */ - tmpblock = get_ptr_atomic(pool->freelist[slindex].page, - pool->freelist[slindex].offset, KM_USER1); - tmpblock->link.prev_page = 0; - tmpblock->link.prev_offset = 0; - put_ptr_atomic(tmpblock, KM_USER1); - } -} - -/* - * Remove block from freelist. Index 'slindex' identifies the freelist. - */ -static void remove_block(struct xv_pool *pool, struct page *page, u32 offset, - struct block_header *block, u32 slindex) -{ - u32 flindex; - struct block_header *tmpblock; - - if (pool->freelist[slindex].page == page - && pool->freelist[slindex].offset == offset) { - remove_block_head(pool, block, slindex); - return; - } - - flindex = slindex / BITS_PER_LONG; - - if (block->link.prev_page) { - tmpblock = get_ptr_atomic(block->link.prev_page, - block->link.prev_offset, KM_USER1); - tmpblock->link.next_page = block->link.next_page; - tmpblock->link.next_offset = block->link.next_offset; - put_ptr_atomic(tmpblock, KM_USER1); - } - - if (block->link.next_page) { - tmpblock = get_ptr_atomic(block->link.next_page, - block->link.next_offset, KM_USER1); - tmpblock->link.prev_page = block->link.prev_page; - tmpblock->link.prev_offset = block->link.prev_offset; - put_ptr_atomic(tmpblock, KM_USER1); - } -} - -/* - * Allocate a page and add it to freelist of given pool. - */ -static int grow_pool(struct xv_pool *pool, gfp_t flags) -{ - struct page *page; - struct block_header *block; - - page = alloc_page(flags); - if (unlikely(!page)) - return -ENOMEM; - - stat_inc(&pool->total_pages); - - spin_lock(&pool->lock); - block = get_ptr_atomic(page, 0, KM_USER0); - - block->size = PAGE_SIZE - XV_ALIGN; - set_flag(block, BLOCK_FREE); - clear_flag(block, PREV_FREE); - set_blockprev(block, 0); - - insert_block(pool, page, 0, block); - - put_ptr_atomic(block, KM_USER0); - spin_unlock(&pool->lock); - - return 0; -} - -/* - * Create a memory pool. Allocates freelist, bitmaps and other - * per-pool metadata. - */ -struct xv_pool *xv_create_pool(void) -{ - u32 ovhd_size; - struct xv_pool *pool; - - ovhd_size = roundup(sizeof(*pool), PAGE_SIZE); - pool = kzalloc(ovhd_size, GFP_KERNEL); - if (!pool) - return NULL; - - spin_lock_init(&pool->lock); - - return pool; -} - -void xv_destroy_pool(struct xv_pool *pool) -{ - kfree(pool); -} - -/** - * xv_malloc - Allocate block of given size from pool. - * @pool: pool to allocate from - * @size: size of block to allocate - * @page: page no. that holds the object - * @offset: location of object within page - * - * On success, identifies block allocated - * and 0 is returned. On failure, is set to - * 0 and -ENOMEM is returned. - * - * Allocation requests with size > XV_MAX_ALLOC_SIZE will fail. - */ -int xv_malloc(struct xv_pool *pool, u32 size, struct page **page, - u32 *offset, gfp_t flags) -{ - int error; - u32 index, tmpsize, origsize, tmpoffset; - struct block_header *block, *tmpblock; - - *page = NULL; - *offset = 0; - origsize = size; - - if (unlikely(!size || size > XV_MAX_ALLOC_SIZE)) - return -ENOMEM; - - size = ALIGN(size, XV_ALIGN); - - spin_lock(&pool->lock); - - index = find_block(pool, size, page, offset); - - if (!*page) { - spin_unlock(&pool->lock); - if (flags & GFP_NOWAIT) - return -ENOMEM; - error = grow_pool(pool, flags); - if (unlikely(error)) - return error; - - spin_lock(&pool->lock); - index = find_block(pool, size, page, offset); - } - - if (!*page) { - spin_unlock(&pool->lock); - return -ENOMEM; - } - - block = get_ptr_atomic(*page, *offset, KM_USER0); - - remove_block_head(pool, block, index); - - /* Split the block if required */ - tmpoffset = *offset + size + XV_ALIGN; - tmpsize = block->size - size; - tmpblock = (struct block_header *)((char *)block + size + XV_ALIGN); - if (tmpsize) { - tmpblock->size = tmpsize - XV_ALIGN; - set_flag(tmpblock, BLOCK_FREE); - clear_flag(tmpblock, PREV_FREE); - - set_blockprev(tmpblock, *offset); - if (tmpblock->size >= XV_MIN_ALLOC_SIZE) - insert_block(pool, *page, tmpoffset, tmpblock); - - if (tmpoffset + XV_ALIGN + tmpblock->size != PAGE_SIZE) { - tmpblock = BLOCK_NEXT(tmpblock); - set_blockprev(tmpblock, tmpoffset); - } - } else { - /* This block is exact fit */ - if (tmpoffset != PAGE_SIZE) - clear_flag(tmpblock, PREV_FREE); - } - - block->size = origsize; - clear_flag(block, BLOCK_FREE); - - put_ptr_atomic(block, KM_USER0); - spin_unlock(&pool->lock); - - *offset += XV_ALIGN; - - return 0; -} - -/* - * Free block identified with - */ -void xv_free(struct xv_pool *pool, struct page *page, u32 offset) -{ - void *page_start; - struct block_header *block, *tmpblock; - - offset -= XV_ALIGN; - - spin_lock(&pool->lock); - - page_start = get_ptr_atomic(page, 0, KM_USER0); - block = (struct block_header *)((char *)page_start + offset); - - /* Catch double free bugs */ - BUG_ON(test_flag(block, BLOCK_FREE)); - - block->size = ALIGN(block->size, XV_ALIGN); - - tmpblock = BLOCK_NEXT(block); - if (offset + block->size + XV_ALIGN == PAGE_SIZE) - tmpblock = NULL; - - /* Merge next block if its free */ - if (tmpblock && test_flag(tmpblock, BLOCK_FREE)) { - /* - * Blocks smaller than XV_MIN_ALLOC_SIZE - * are not inserted in any free list. - */ - if (tmpblock->size >= XV_MIN_ALLOC_SIZE) { - remove_block(pool, page, - offset + block->size + XV_ALIGN, tmpblock, - get_index_for_insert(tmpblock->size)); - } - block->size += tmpblock->size + XV_ALIGN; - } - - /* Merge previous block if its free */ - if (test_flag(block, PREV_FREE)) { - tmpblock = (struct block_header *)((char *)(page_start) + - get_blockprev(block)); - offset = offset - tmpblock->size - XV_ALIGN; - - if (tmpblock->size >= XV_MIN_ALLOC_SIZE) - remove_block(pool, page, offset, tmpblock, - get_index_for_insert(tmpblock->size)); - - tmpblock->size += block->size + XV_ALIGN; - block = tmpblock; - } - - /* No used objects in this page. Free it. */ - if (block->size == PAGE_SIZE - XV_ALIGN) { - put_ptr_atomic(page_start, KM_USER0); - spin_unlock(&pool->lock); - - __free_page(page); - stat_dec(&pool->total_pages); - return; - } - - set_flag(block, BLOCK_FREE); - if (block->size >= XV_MIN_ALLOC_SIZE) - insert_block(pool, page, offset, block); - - if (offset + block->size + XV_ALIGN != PAGE_SIZE) { - tmpblock = BLOCK_NEXT(block); - set_flag(tmpblock, PREV_FREE); - set_blockprev(tmpblock, offset); - } - - put_ptr_atomic(page_start, KM_USER0); - spin_unlock(&pool->lock); -} - -u32 xv_get_object_size(void *obj) -{ - struct block_header *blk; - - blk = (struct block_header *)((char *)(obj) - XV_ALIGN); - return blk->size; -} - -/* - * Returns total memory used by allocator (userdata + metadata) - */ -u64 xv_get_total_size_bytes(struct xv_pool *pool) -{ - return pool->total_pages << PAGE_SHIFT; -} diff --git a/drivers/staging/ramzswap/xvmalloc.h b/drivers/staging/ramzswap/xvmalloc.h deleted file mode 100644 index 5b1a81a..0000000 --- a/drivers/staging/ramzswap/xvmalloc.h +++ /dev/null @@ -1,30 +0,0 @@ -/* - * xvmalloc memory allocator - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - */ - -#ifndef _XV_MALLOC_H_ -#define _XV_MALLOC_H_ - -#include - -struct xv_pool; - -struct xv_pool *xv_create_pool(void); -void xv_destroy_pool(struct xv_pool *pool); - -int xv_malloc(struct xv_pool *pool, u32 size, struct page **page, - u32 *offset, gfp_t flags); -void xv_free(struct xv_pool *pool, struct page *page, u32 offset); - -u32 xv_get_object_size(void *obj); -u64 xv_get_total_size_bytes(struct xv_pool *pool); - -#endif diff --git a/drivers/staging/ramzswap/xvmalloc_int.h b/drivers/staging/ramzswap/xvmalloc_int.h deleted file mode 100644 index e23ed5c..0000000 --- a/drivers/staging/ramzswap/xvmalloc_int.h +++ /dev/null @@ -1,86 +0,0 @@ -/* - * xvmalloc memory allocator - * - * Copyright (C) 2008, 2009, 2010 Nitin Gupta - * - * This code is released using a dual license strategy: BSD/GPL - * You can choose the licence that better fits your requirements. - * - * Released under the terms of 3-clause BSD License - * Released under the terms of GNU General Public License Version 2.0 - */ - -#ifndef _XV_MALLOC_INT_H_ -#define _XV_MALLOC_INT_H_ - -#include -#include - -/* User configurable params */ - -/* Must be power of two */ -#define XV_ALIGN_SHIFT 2 -#define XV_ALIGN (1 << XV_ALIGN_SHIFT) -#define XV_ALIGN_MASK (XV_ALIGN - 1) - -/* This must be greater than sizeof(link_free) */ -#define XV_MIN_ALLOC_SIZE 32 -#define XV_MAX_ALLOC_SIZE (PAGE_SIZE - XV_ALIGN) - -/* Free lists are separated by FL_DELTA bytes */ -#define FL_DELTA_SHIFT 3 -#define FL_DELTA (1 << FL_DELTA_SHIFT) -#define FL_DELTA_MASK (FL_DELTA - 1) -#define NUM_FREE_LISTS ((XV_MAX_ALLOC_SIZE - XV_MIN_ALLOC_SIZE) \ - / FL_DELTA + 1) - -#define MAX_FLI DIV_ROUND_UP(NUM_FREE_LISTS, BITS_PER_LONG) - -/* End of user params */ - -enum blockflags { - BLOCK_FREE, - PREV_FREE, - __NR_BLOCKFLAGS, -}; - -#define FLAGS_MASK XV_ALIGN_MASK -#define PREV_MASK (~FLAGS_MASK) - -struct freelist_entry { - struct page *page; - u16 offset; - u16 pad; -}; - -struct link_free { - struct page *prev_page; - struct page *next_page; - u16 prev_offset; - u16 next_offset; -}; - -struct block_header { - union { - /* This common header must be XV_ALIGN bytes */ - u8 common[XV_ALIGN]; - struct { - u16 size; - u16 prev; - }; - }; - struct link_free link; -}; - -struct xv_pool { - ulong flbitmap; - ulong slbitmap[MAX_FLI]; - spinlock_t lock; - - struct freelist_entry freelist[NUM_FREE_LISTS]; - - /* stats */ - u64 total_pages; -}; - -#endif diff --git a/drivers/staging/zram/Kconfig b/drivers/staging/zram/Kconfig new file mode 100644 index 0000000..5bcfe16 --- /dev/null +++ b/drivers/staging/zram/Kconfig @@ -0,0 +1,28 @@ +config ZRAM + tristate "Compressed RAM block device support" + select LZO_COMPRESS + select LZO_DECOMPRESS + default n + help + Creates virtual block devices called /dev/zramX (X = 0, 1, ...). + Pages written to these disks are compressed and stored in memory + itself. These disks allow very fast I/O and compression provides + good amounts of memory savings. + + It has several use cases, for example: /tmp storage, use as swap + disks and maybe many more. + + See zram.txt for more information. + Project home: http://compcache.googlecode.com/ + +config ZRAM_STATS + bool "Enable statistics for compressed RAM disks" + depends on ZRAM + default y + help + Enable statistics collection for compressed RAM devices. Statistics + are exported through ioctl interface, so you have to use zramconfig + program to get them. This adds only a minimal overhead. + + If unsure, say Y. + diff --git a/drivers/staging/zram/Makefile b/drivers/staging/zram/Makefile new file mode 100644 index 0000000..b2c087a --- /dev/null +++ b/drivers/staging/zram/Makefile @@ -0,0 +1,3 @@ +zram-objs := zram_drv.o xvmalloc.o + +obj-$(CONFIG_ZRAM) += zram.o diff --git a/drivers/staging/zram/xvmalloc.c b/drivers/staging/zram/xvmalloc.c new file mode 100644 index 0000000..3fdbb8a --- /dev/null +++ b/drivers/staging/zram/xvmalloc.c @@ -0,0 +1,507 @@ +/* + * xvmalloc memory allocator + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + */ + +#include +#include +#include +#include +#include +#include + +#include "xvmalloc.h" +#include "xvmalloc_int.h" + +static void stat_inc(u64 *value) +{ + *value = *value + 1; +} + +static void stat_dec(u64 *value) +{ + *value = *value - 1; +} + +static int test_flag(struct block_header *block, enum blockflags flag) +{ + return block->prev & BIT(flag); +} + +static void set_flag(struct block_header *block, enum blockflags flag) +{ + block->prev |= BIT(flag); +} + +static void clear_flag(struct block_header *block, enum blockflags flag) +{ + block->prev &= ~BIT(flag); +} + +/* + * Given pair, provide a derefrencable pointer. + * This is called from xv_malloc/xv_free path, so it + * needs to be fast. + */ +static void *get_ptr_atomic(struct page *page, u16 offset, enum km_type type) +{ + unsigned char *base; + + base = kmap_atomic(page, type); + return base + offset; +} + +static void put_ptr_atomic(void *ptr, enum km_type type) +{ + kunmap_atomic(ptr, type); +} + +static u32 get_blockprev(struct block_header *block) +{ + return block->prev & PREV_MASK; +} + +static void set_blockprev(struct block_header *block, u16 new_offset) +{ + block->prev = new_offset | (block->prev & FLAGS_MASK); +} + +static struct block_header *BLOCK_NEXT(struct block_header *block) +{ + return (struct block_header *) + ((char *)block + block->size + XV_ALIGN); +} + +/* + * Get index of free list containing blocks of maximum size + * which is less than or equal to given size. + */ +static u32 get_index_for_insert(u32 size) +{ + if (unlikely(size > XV_MAX_ALLOC_SIZE)) + size = XV_MAX_ALLOC_SIZE; + size &= ~FL_DELTA_MASK; + return (size - XV_MIN_ALLOC_SIZE) >> FL_DELTA_SHIFT; +} + +/* + * Get index of free list having blocks of size greater than + * or equal to requested size. + */ +static u32 get_index(u32 size) +{ + if (unlikely(size < XV_MIN_ALLOC_SIZE)) + size = XV_MIN_ALLOC_SIZE; + size = ALIGN(size, FL_DELTA); + return (size - XV_MIN_ALLOC_SIZE) >> FL_DELTA_SHIFT; +} + +/** + * find_block - find block of at least given size + * @pool: memory pool to search from + * @size: size of block required + * @page: page containing required block + * @offset: offset within the page where block is located. + * + * Searches two level bitmap to locate block of at least + * the given size. If such a block is found, it provides + * to identify this block and returns index + * in freelist where we found this block. + * Otherwise, returns 0 and params are not touched. + */ +static u32 find_block(struct xv_pool *pool, u32 size, + struct page **page, u32 *offset) +{ + ulong flbitmap, slbitmap; + u32 flindex, slindex, slbitstart; + + /* There are no free blocks in this pool */ + if (!pool->flbitmap) + return 0; + + /* Get freelist index correspoding to this size */ + slindex = get_index(size); + slbitmap = pool->slbitmap[slindex / BITS_PER_LONG]; + slbitstart = slindex % BITS_PER_LONG; + + /* + * If freelist is not empty at this index, we found the + * block - head of this list. This is approximate best-fit match. + */ + if (test_bit(slbitstart, &slbitmap)) { + *page = pool->freelist[slindex].page; + *offset = pool->freelist[slindex].offset; + return slindex; + } + + /* + * No best-fit found. Search a bit further in bitmap for a free block. + * Second level bitmap consists of series of 32-bit chunks. Search + * further in the chunk where we expected a best-fit, starting from + * index location found above. + */ + slbitstart++; + slbitmap >>= slbitstart; + + /* Skip this search if we were already at end of this bitmap chunk */ + if ((slbitstart != BITS_PER_LONG) && slbitmap) { + slindex += __ffs(slbitmap) + 1; + *page = pool->freelist[slindex].page; + *offset = pool->freelist[slindex].offset; + return slindex; + } + + /* Now do a full two-level bitmap search to find next nearest fit */ + flindex = slindex / BITS_PER_LONG; + + flbitmap = (pool->flbitmap) >> (flindex + 1); + if (!flbitmap) + return 0; + + flindex += __ffs(flbitmap) + 1; + slbitmap = pool->slbitmap[flindex]; + slindex = (flindex * BITS_PER_LONG) + __ffs(slbitmap); + *page = pool->freelist[slindex].page; + *offset = pool->freelist[slindex].offset; + + return slindex; +} + +/* + * Insert block at in freelist of given pool. + * freelist used depends on block size. + */ +static void insert_block(struct xv_pool *pool, struct page *page, u32 offset, + struct block_header *block) +{ + u32 flindex, slindex; + struct block_header *nextblock; + + slindex = get_index_for_insert(block->size); + flindex = slindex / BITS_PER_LONG; + + block->link.prev_page = 0; + block->link.prev_offset = 0; + block->link.next_page = pool->freelist[slindex].page; + block->link.next_offset = pool->freelist[slindex].offset; + pool->freelist[slindex].page = page; + pool->freelist[slindex].offset = offset; + + if (block->link.next_page) { + nextblock = get_ptr_atomic(block->link.next_page, + block->link.next_offset, KM_USER1); + nextblock->link.prev_page = page; + nextblock->link.prev_offset = offset; + put_ptr_atomic(nextblock, KM_USER1); + } + + __set_bit(slindex % BITS_PER_LONG, &pool->slbitmap[flindex]); + __set_bit(flindex, &pool->flbitmap); +} + +/* + * Remove block from head of freelist. Index 'slindex' identifies the freelist. + */ +static void remove_block_head(struct xv_pool *pool, + struct block_header *block, u32 slindex) +{ + struct block_header *tmpblock; + u32 flindex = slindex / BITS_PER_LONG; + + pool->freelist[slindex].page = block->link.next_page; + pool->freelist[slindex].offset = block->link.next_offset; + block->link.prev_page = 0; + block->link.prev_offset = 0; + + if (!pool->freelist[slindex].page) { + __clear_bit(slindex % BITS_PER_LONG, &pool->slbitmap[flindex]); + if (!pool->slbitmap[flindex]) + __clear_bit(flindex, &pool->flbitmap); + } else { + /* + * DEBUG ONLY: We need not reinitialize freelist head previous + * pointer to 0 - we never depend on its value. But just for + * sanity, lets do it. + */ + tmpblock = get_ptr_atomic(pool->freelist[slindex].page, + pool->freelist[slindex].offset, KM_USER1); + tmpblock->link.prev_page = 0; + tmpblock->link.prev_offset = 0; + put_ptr_atomic(tmpblock, KM_USER1); + } +} + +/* + * Remove block from freelist. Index 'slindex' identifies the freelist. + */ +static void remove_block(struct xv_pool *pool, struct page *page, u32 offset, + struct block_header *block, u32 slindex) +{ + u32 flindex; + struct block_header *tmpblock; + + if (pool->freelist[slindex].page == page + && pool->freelist[slindex].offset == offset) { + remove_block_head(pool, block, slindex); + return; + } + + flindex = slindex / BITS_PER_LONG; + + if (block->link.prev_page) { + tmpblock = get_ptr_atomic(block->link.prev_page, + block->link.prev_offset, KM_USER1); + tmpblock->link.next_page = block->link.next_page; + tmpblock->link.next_offset = block->link.next_offset; + put_ptr_atomic(tmpblock, KM_USER1); + } + + if (block->link.next_page) { + tmpblock = get_ptr_atomic(block->link.next_page, + block->link.next_offset, KM_USER1); + tmpblock->link.prev_page = block->link.prev_page; + tmpblock->link.prev_offset = block->link.prev_offset; + put_ptr_atomic(tmpblock, KM_USER1); + } +} + +/* + * Allocate a page and add it to freelist of given pool. + */ +static int grow_pool(struct xv_pool *pool, gfp_t flags) +{ + struct page *page; + struct block_header *block; + + page = alloc_page(flags); + if (unlikely(!page)) + return -ENOMEM; + + stat_inc(&pool->total_pages); + + spin_lock(&pool->lock); + block = get_ptr_atomic(page, 0, KM_USER0); + + block->size = PAGE_SIZE - XV_ALIGN; + set_flag(block, BLOCK_FREE); + clear_flag(block, PREV_FREE); + set_blockprev(block, 0); + + insert_block(pool, page, 0, block); + + put_ptr_atomic(block, KM_USER0); + spin_unlock(&pool->lock); + + return 0; +} + +/* + * Create a memory pool. Allocates freelist, bitmaps and other + * per-pool metadata. + */ +struct xv_pool *xv_create_pool(void) +{ + u32 ovhd_size; + struct xv_pool *pool; + + ovhd_size = roundup(sizeof(*pool), PAGE_SIZE); + pool = kzalloc(ovhd_size, GFP_KERNEL); + if (!pool) + return NULL; + + spin_lock_init(&pool->lock); + + return pool; +} + +void xv_destroy_pool(struct xv_pool *pool) +{ + kfree(pool); +} + +/** + * xv_malloc - Allocate block of given size from pool. + * @pool: pool to allocate from + * @size: size of block to allocate + * @page: page no. that holds the object + * @offset: location of object within page + * + * On success, identifies block allocated + * and 0 is returned. On failure, is set to + * 0 and -ENOMEM is returned. + * + * Allocation requests with size > XV_MAX_ALLOC_SIZE will fail. + */ +int xv_malloc(struct xv_pool *pool, u32 size, struct page **page, + u32 *offset, gfp_t flags) +{ + int error; + u32 index, tmpsize, origsize, tmpoffset; + struct block_header *block, *tmpblock; + + *page = NULL; + *offset = 0; + origsize = size; + + if (unlikely(!size || size > XV_MAX_ALLOC_SIZE)) + return -ENOMEM; + + size = ALIGN(size, XV_ALIGN); + + spin_lock(&pool->lock); + + index = find_block(pool, size, page, offset); + + if (!*page) { + spin_unlock(&pool->lock); + if (flags & GFP_NOWAIT) + return -ENOMEM; + error = grow_pool(pool, flags); + if (unlikely(error)) + return error; + + spin_lock(&pool->lock); + index = find_block(pool, size, page, offset); + } + + if (!*page) { + spin_unlock(&pool->lock); + return -ENOMEM; + } + + block = get_ptr_atomic(*page, *offset, KM_USER0); + + remove_block_head(pool, block, index); + + /* Split the block if required */ + tmpoffset = *offset + size + XV_ALIGN; + tmpsize = block->size - size; + tmpblock = (struct block_header *)((char *)block + size + XV_ALIGN); + if (tmpsize) { + tmpblock->size = tmpsize - XV_ALIGN; + set_flag(tmpblock, BLOCK_FREE); + clear_flag(tmpblock, PREV_FREE); + + set_blockprev(tmpblock, *offset); + if (tmpblock->size >= XV_MIN_ALLOC_SIZE) + insert_block(pool, *page, tmpoffset, tmpblock); + + if (tmpoffset + XV_ALIGN + tmpblock->size != PAGE_SIZE) { + tmpblock = BLOCK_NEXT(tmpblock); + set_blockprev(tmpblock, tmpoffset); + } + } else { + /* This block is exact fit */ + if (tmpoffset != PAGE_SIZE) + clear_flag(tmpblock, PREV_FREE); + } + + block->size = origsize; + clear_flag(block, BLOCK_FREE); + + put_ptr_atomic(block, KM_USER0); + spin_unlock(&pool->lock); + + *offset += XV_ALIGN; + + return 0; +} + +/* + * Free block identified with + */ +void xv_free(struct xv_pool *pool, struct page *page, u32 offset) +{ + void *page_start; + struct block_header *block, *tmpblock; + + offset -= XV_ALIGN; + + spin_lock(&pool->lock); + + page_start = get_ptr_atomic(page, 0, KM_USER0); + block = (struct block_header *)((char *)page_start + offset); + + /* Catch double free bugs */ + BUG_ON(test_flag(block, BLOCK_FREE)); + + block->size = ALIGN(block->size, XV_ALIGN); + + tmpblock = BLOCK_NEXT(block); + if (offset + block->size + XV_ALIGN == PAGE_SIZE) + tmpblock = NULL; + + /* Merge next block if its free */ + if (tmpblock && test_flag(tmpblock, BLOCK_FREE)) { + /* + * Blocks smaller than XV_MIN_ALLOC_SIZE + * are not inserted in any free list. + */ + if (tmpblock->size >= XV_MIN_ALLOC_SIZE) { + remove_block(pool, page, + offset + block->size + XV_ALIGN, tmpblock, + get_index_for_insert(tmpblock->size)); + } + block->size += tmpblock->size + XV_ALIGN; + } + + /* Merge previous block if its free */ + if (test_flag(block, PREV_FREE)) { + tmpblock = (struct block_header *)((char *)(page_start) + + get_blockprev(block)); + offset = offset - tmpblock->size - XV_ALIGN; + + if (tmpblock->size >= XV_MIN_ALLOC_SIZE) + remove_block(pool, page, offset, tmpblock, + get_index_for_insert(tmpblock->size)); + + tmpblock->size += block->size + XV_ALIGN; + block = tmpblock; + } + + /* No used objects in this page. Free it. */ + if (block->size == PAGE_SIZE - XV_ALIGN) { + put_ptr_atomic(page_start, KM_USER0); + spin_unlock(&pool->lock); + + __free_page(page); + stat_dec(&pool->total_pages); + return; + } + + set_flag(block, BLOCK_FREE); + if (block->size >= XV_MIN_ALLOC_SIZE) + insert_block(pool, page, offset, block); + + if (offset + block->size + XV_ALIGN != PAGE_SIZE) { + tmpblock = BLOCK_NEXT(block); + set_flag(tmpblock, PREV_FREE); + set_blockprev(tmpblock, offset); + } + + put_ptr_atomic(page_start, KM_USER0); + spin_unlock(&pool->lock); +} + +u32 xv_get_object_size(void *obj) +{ + struct block_header *blk; + + blk = (struct block_header *)((char *)(obj) - XV_ALIGN); + return blk->size; +} + +/* + * Returns total memory used by allocator (userdata + metadata) + */ +u64 xv_get_total_size_bytes(struct xv_pool *pool) +{ + return pool->total_pages << PAGE_SHIFT; +} diff --git a/drivers/staging/zram/xvmalloc.h b/drivers/staging/zram/xvmalloc.h new file mode 100644 index 0000000..5b1a81a --- /dev/null +++ b/drivers/staging/zram/xvmalloc.h @@ -0,0 +1,30 @@ +/* + * xvmalloc memory allocator + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + */ + +#ifndef _XV_MALLOC_H_ +#define _XV_MALLOC_H_ + +#include + +struct xv_pool; + +struct xv_pool *xv_create_pool(void); +void xv_destroy_pool(struct xv_pool *pool); + +int xv_malloc(struct xv_pool *pool, u32 size, struct page **page, + u32 *offset, gfp_t flags); +void xv_free(struct xv_pool *pool, struct page *page, u32 offset); + +u32 xv_get_object_size(void *obj); +u64 xv_get_total_size_bytes(struct xv_pool *pool); + +#endif diff --git a/drivers/staging/zram/xvmalloc_int.h b/drivers/staging/zram/xvmalloc_int.h new file mode 100644 index 0000000..e23ed5c --- /dev/null +++ b/drivers/staging/zram/xvmalloc_int.h @@ -0,0 +1,86 @@ +/* + * xvmalloc memory allocator + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + */ + +#ifndef _XV_MALLOC_INT_H_ +#define _XV_MALLOC_INT_H_ + +#include +#include + +/* User configurable params */ + +/* Must be power of two */ +#define XV_ALIGN_SHIFT 2 +#define XV_ALIGN (1 << XV_ALIGN_SHIFT) +#define XV_ALIGN_MASK (XV_ALIGN - 1) + +/* This must be greater than sizeof(link_free) */ +#define XV_MIN_ALLOC_SIZE 32 +#define XV_MAX_ALLOC_SIZE (PAGE_SIZE - XV_ALIGN) + +/* Free lists are separated by FL_DELTA bytes */ +#define FL_DELTA_SHIFT 3 +#define FL_DELTA (1 << FL_DELTA_SHIFT) +#define FL_DELTA_MASK (FL_DELTA - 1) +#define NUM_FREE_LISTS ((XV_MAX_ALLOC_SIZE - XV_MIN_ALLOC_SIZE) \ + / FL_DELTA + 1) + +#define MAX_FLI DIV_ROUND_UP(NUM_FREE_LISTS, BITS_PER_LONG) + +/* End of user params */ + +enum blockflags { + BLOCK_FREE, + PREV_FREE, + __NR_BLOCKFLAGS, +}; + +#define FLAGS_MASK XV_ALIGN_MASK +#define PREV_MASK (~FLAGS_MASK) + +struct freelist_entry { + struct page *page; + u16 offset; + u16 pad; +}; + +struct link_free { + struct page *prev_page; + struct page *next_page; + u16 prev_offset; + u16 next_offset; +}; + +struct block_header { + union { + /* This common header must be XV_ALIGN bytes */ + u8 common[XV_ALIGN]; + struct { + u16 size; + u16 prev; + }; + }; + struct link_free link; +}; + +struct xv_pool { + ulong flbitmap; + ulong slbitmap[MAX_FLI]; + spinlock_t lock; + + struct freelist_entry freelist[NUM_FREE_LISTS]; + + /* stats */ + u64 total_pages; +}; + +#endif diff --git a/drivers/staging/zram/zram.txt b/drivers/staging/zram/zram.txt new file mode 100644 index 0000000..9694acf --- /dev/null +++ b/drivers/staging/zram/zram.txt @@ -0,0 +1,51 @@ +ramzswap: Compressed RAM based swap device +------------------------------------------- + +Project home: http://compcache.googlecode.com/ + +* Introduction + +The ramzswap module creates RAM based block devices which can (only) be used as +swap disks. Pages swapped to these devices are compressed and stored in memory +itself. See project home for use cases, performance numbers and a lot more. + +Individual ramzswap devices are configured and initialized using rzscontrol +userspace utility as shown in examples below. See rzscontrol man page for more +details. + +* Usage + +Following shows a typical sequence of steps for using ramzswap. + +1) Load Modules: + modprobe ramzswap num_devices=4 + This creates 4 (uninitialized) devices: /dev/ramzswap{0,1,2,3} + (num_devices parameter is optional. Default: 1) + +2) Initialize: + Use rzscontrol utility to configure and initialize individual + ramzswap devices. Example: + rzscontrol /dev/ramzswap2 --init # uses default value of disksize_kb + + *See rzscontrol man page for more details and examples* + +3) Activate: + swapon /dev/ramzswap2 # or any other initialized ramzswap device + +4) Stats: + rzscontrol /dev/ramzswap2 --stats + +5) Deactivate: + swapoff /dev/ramzswap2 + +6) Reset: + rzscontrol /dev/ramzswap2 --reset + (This frees all the memory allocated for this device). + + +Please report any problems at: + - Mailing list: linux-mm-cc at laptop dot org + - Issue tracker: http://code.google.com/p/compcache/issues/list + +Nitin Gupta +ngupta@vflare.org diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c new file mode 100644 index 0000000..e9b064c --- /dev/null +++ b/drivers/staging/zram/zram_drv.c @@ -0,0 +1,805 @@ +/* + * Compressed RAM based swap device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com + */ + +#define KMSG_COMPONENT "ramzswap" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "zram_drv.h" + +/* Globals */ +static int ramzswap_major; +static struct ramzswap *devices; + +/* Module params (documentation at end) */ +static unsigned int num_devices; + +static int rzs_test_flag(struct ramzswap *rzs, u32 index, + enum rzs_pageflags flag) +{ + return rzs->table[index].flags & BIT(flag); +} + +static void rzs_set_flag(struct ramzswap *rzs, u32 index, + enum rzs_pageflags flag) +{ + rzs->table[index].flags |= BIT(flag); +} + +static void rzs_clear_flag(struct ramzswap *rzs, u32 index, + enum rzs_pageflags flag) +{ + rzs->table[index].flags &= ~BIT(flag); +} + +static int page_zero_filled(void *ptr) +{ + unsigned int pos; + unsigned long *page; + + page = (unsigned long *)ptr; + + for (pos = 0; pos != PAGE_SIZE / sizeof(*page); pos++) { + if (page[pos]) + return 0; + } + + return 1; +} + +static void ramzswap_set_disksize(struct ramzswap *rzs, size_t totalram_bytes) +{ + if (!rzs->disksize) { + pr_info( + "disk size not provided. You can use disksize_kb module " + "param to specify size.\nUsing default: (%u%% of RAM).\n", + default_disksize_perc_ram + ); + rzs->disksize = default_disksize_perc_ram * + (totalram_bytes / 100); + } + + if (rzs->disksize > 2 * (totalram_bytes)) { + pr_info( + "There is little point creating a ramzswap of greater than " + "twice the size of memory since we expect a 2:1 compression " + "ratio. Note that ramzswap uses about 0.1%% of the size of " + "the swap device when not in use so a huge ramzswap is " + "wasteful.\n" + "\tMemory Size: %zu kB\n" + "\tSize you selected: %zu kB\n" + "Continuing anyway ...\n", + totalram_bytes >> 10, rzs->disksize + ); + } + + rzs->disksize &= PAGE_MASK; +} + +static void ramzswap_ioctl_get_stats(struct ramzswap *rzs, + struct ramzswap_ioctl_stats *s) +{ + s->disksize = rzs->disksize; + +#if defined(CONFIG_RAMZSWAP_STATS) + { + struct ramzswap_stats *rs = &rzs->stats; + size_t succ_writes, mem_used; + unsigned int good_compress_perc = 0, no_compress_perc = 0; + + mem_used = xv_get_total_size_bytes(rzs->mem_pool) + + (rs->pages_expand << PAGE_SHIFT); + succ_writes = rzs_stat64_read(rzs, &rs->num_writes) - + rzs_stat64_read(rzs, &rs->failed_writes); + + if (succ_writes && rs->pages_stored) { + good_compress_perc = rs->good_compress * 100 + / rs->pages_stored; + no_compress_perc = rs->pages_expand * 100 + / rs->pages_stored; + } + + s->num_reads = rzs_stat64_read(rzs, &rs->num_reads); + s->num_writes = rzs_stat64_read(rzs, &rs->num_writes); + s->failed_reads = rzs_stat64_read(rzs, &rs->failed_reads); + s->failed_writes = rzs_stat64_read(rzs, &rs->failed_writes); + s->invalid_io = rzs_stat64_read(rzs, &rs->invalid_io); + s->notify_free = rzs_stat64_read(rzs, &rs->notify_free); + s->pages_zero = rs->pages_zero; + + s->good_compress_pct = good_compress_perc; + s->pages_expand_pct = no_compress_perc; + + s->pages_stored = rs->pages_stored; + s->pages_used = mem_used >> PAGE_SHIFT; + s->orig_data_size = rs->pages_stored << PAGE_SHIFT; + s->compr_data_size = rs->compr_size; + s->mem_used_total = mem_used; + } +#endif /* CONFIG_RAMZSWAP_STATS */ +} + +static void ramzswap_free_page(struct ramzswap *rzs, size_t index) +{ + u32 clen; + void *obj; + + struct page *page = rzs->table[index].page; + u32 offset = rzs->table[index].offset; + + if (unlikely(!page)) { + /* + * No memory is allocated for zero filled pages. + * Simply clear zero page flag. + */ + if (rzs_test_flag(rzs, index, RZS_ZERO)) { + rzs_clear_flag(rzs, index, RZS_ZERO); + rzs_stat_dec(&rzs->stats.pages_zero); + } + return; + } + + if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) { + clen = PAGE_SIZE; + __free_page(page); + rzs_clear_flag(rzs, index, RZS_UNCOMPRESSED); + rzs_stat_dec(&rzs->stats.pages_expand); + goto out; + } + + obj = kmap_atomic(page, KM_USER0) + offset; + clen = xv_get_object_size(obj) - sizeof(struct zobj_header); + kunmap_atomic(obj, KM_USER0); + + xv_free(rzs->mem_pool, page, offset); + if (clen <= PAGE_SIZE / 2) + rzs_stat_dec(&rzs->stats.good_compress); + +out: + rzs->stats.compr_size -= clen; + rzs_stat_dec(&rzs->stats.pages_stored); + + rzs->table[index].page = NULL; + rzs->table[index].offset = 0; +} + +static void handle_zero_page(struct page *page) +{ + void *user_mem; + + user_mem = kmap_atomic(page, KM_USER0); + memset(user_mem, 0, PAGE_SIZE); + kunmap_atomic(user_mem, KM_USER0); + + flush_dcache_page(page); +} + +static void handle_uncompressed_page(struct ramzswap *rzs, + struct page *page, u32 index) +{ + unsigned char *user_mem, *cmem; + + user_mem = kmap_atomic(page, KM_USER0); + cmem = kmap_atomic(rzs->table[index].page, KM_USER1) + + rzs->table[index].offset; + + memcpy(user_mem, cmem, PAGE_SIZE); + kunmap_atomic(user_mem, KM_USER0); + kunmap_atomic(cmem, KM_USER1); + + flush_dcache_page(page); +} + +static int ramzswap_read(struct ramzswap *rzs, struct bio *bio) +{ + + int i; + u32 index; + struct bio_vec *bvec; + + rzs_stat64_inc(rzs, &rzs->stats.num_reads); + + index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; + bio_for_each_segment(bvec, bio, i) { + int ret; + size_t clen; + struct page *page; + struct zobj_header *zheader; + unsigned char *user_mem, *cmem; + + page = bvec->bv_page; + + if (rzs_test_flag(rzs, index, RZS_ZERO)) { + handle_zero_page(page); + continue; + } + + /* Requested page is not present in compressed area */ + if (unlikely(!rzs->table[index].page)) { + pr_debug("Read before write: sector=%lu, size=%u", + (ulong)(bio->bi_sector), bio->bi_size); + /* Do nothing */ + continue; + } + + /* Page is stored uncompressed since it's incompressible */ + if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) { + handle_uncompressed_page(rzs, page, index); + continue; + } + + user_mem = kmap_atomic(page, KM_USER0); + clen = PAGE_SIZE; + + cmem = kmap_atomic(rzs->table[index].page, KM_USER1) + + rzs->table[index].offset; + + ret = lzo1x_decompress_safe( + cmem + sizeof(*zheader), + xv_get_object_size(cmem) - sizeof(*zheader), + user_mem, &clen); + + kunmap_atomic(user_mem, KM_USER0); + kunmap_atomic(cmem, KM_USER1); + + /* Should NEVER happen. Return bio error if it does. */ + if (unlikely(ret != LZO_E_OK)) { + pr_err("Decompression failed! err=%d, page=%u\n", + ret, index); + rzs_stat64_inc(rzs, &rzs->stats.failed_reads); + goto out; + } + + flush_dcache_page(page); + index++; + } + + set_bit(BIO_UPTODATE, &bio->bi_flags); + bio_endio(bio, 0); + return 0; + +out: + bio_io_error(bio); + return 0; +} + +static int ramzswap_write(struct ramzswap *rzs, struct bio *bio) +{ + int i; + u32 index; + struct bio_vec *bvec; + + rzs_stat64_inc(rzs, &rzs->stats.num_writes); + + index = bio->bi_sector >> SECTORS_PER_PAGE_SHIFT; + + bio_for_each_segment(bvec, bio, i) { + int ret; + u32 offset; + size_t clen; + struct zobj_header *zheader; + struct page *page, *page_store; + unsigned char *user_mem, *cmem, *src; + + page = bvec->bv_page; + src = rzs->compress_buffer; + + /* + * System overwrites unused sectors. Free memory associated + * with this sector now. + */ + if (rzs->table[index].page || + rzs_test_flag(rzs, index, RZS_ZERO)) + ramzswap_free_page(rzs, index); + + mutex_lock(&rzs->lock); + + user_mem = kmap_atomic(page, KM_USER0); + if (page_zero_filled(user_mem)) { + kunmap_atomic(user_mem, KM_USER0); + mutex_unlock(&rzs->lock); + rzs_stat_inc(&rzs->stats.pages_zero); + rzs_set_flag(rzs, index, RZS_ZERO); + continue; + } + + ret = lzo1x_1_compress(user_mem, PAGE_SIZE, src, &clen, + rzs->compress_workmem); + + kunmap_atomic(user_mem, KM_USER0); + + if (unlikely(ret != LZO_E_OK)) { + mutex_unlock(&rzs->lock); + pr_err("Compression failed! err=%d\n", ret); + rzs_stat64_inc(rzs, &rzs->stats.failed_writes); + goto out; + } + + /* + * Page is incompressible. Store it as-is (uncompressed) + * since we do not want to return too many swap write + * errors which has side effect of hanging the system. + */ + if (unlikely(clen > max_zpage_size)) { + clen = PAGE_SIZE; + page_store = alloc_page(GFP_NOIO | __GFP_HIGHMEM); + if (unlikely(!page_store)) { + mutex_unlock(&rzs->lock); + pr_info("Error allocating memory for " + "incompressible page: %u\n", index); + rzs_stat64_inc(rzs, &rzs->stats.failed_writes); + goto out; + } + + offset = 0; + rzs_set_flag(rzs, index, RZS_UNCOMPRESSED); + rzs_stat_inc(&rzs->stats.pages_expand); + rzs->table[index].page = page_store; + src = kmap_atomic(page, KM_USER0); + goto memstore; + } + + if (xv_malloc(rzs->mem_pool, clen + sizeof(*zheader), + &rzs->table[index].page, &offset, + GFP_NOIO | __GFP_HIGHMEM)) { + mutex_unlock(&rzs->lock); + pr_info("Error allocating memory for compressed " + "page: %u, size=%zu\n", index, clen); + rzs_stat64_inc(rzs, &rzs->stats.failed_writes); + goto out; + } + +memstore: + rzs->table[index].offset = offset; + + cmem = kmap_atomic(rzs->table[index].page, KM_USER1) + + rzs->table[index].offset; + +#if 0 + /* Back-reference needed for memory defragmentation */ + if (!rzs_test_flag(rzs, index, RZS_UNCOMPRESSED)) { + zheader = (struct zobj_header *)cmem; + zheader->table_idx = index; + cmem += sizeof(*zheader); + } +#endif + + memcpy(cmem, src, clen); + + kunmap_atomic(cmem, KM_USER1); + if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) + kunmap_atomic(src, KM_USER0); + + /* Update stats */ + rzs->stats.compr_size += clen; + rzs_stat_inc(&rzs->stats.pages_stored); + if (clen <= PAGE_SIZE / 2) + rzs_stat_inc(&rzs->stats.good_compress); + + mutex_unlock(&rzs->lock); + index++; + } + + set_bit(BIO_UPTODATE, &bio->bi_flags); + bio_endio(bio, 0); + return 0; + +out: + bio_io_error(bio); + return 0; +} + +/* + * Check if request is within bounds and page aligned. + */ +static inline int valid_io_request(struct ramzswap *rzs, struct bio *bio) +{ + if (unlikely( + (bio->bi_sector >= (rzs->disksize >> SECTOR_SHIFT)) || + (bio->bi_sector & (SECTORS_PER_PAGE - 1)) || + (bio->bi_size & (PAGE_SIZE - 1)))) { + + return 0; + } + + /* I/O request is valid */ + return 1; +} + +/* + * Handler function for all ramzswap I/O requests. + */ +static int ramzswap_make_request(struct request_queue *queue, struct bio *bio) +{ + int ret = 0; + struct ramzswap *rzs = queue->queuedata; + + if (unlikely(!rzs->init_done)) { + bio_io_error(bio); + return 0; + } + + if (!valid_io_request(rzs, bio)) { + rzs_stat64_inc(rzs, &rzs->stats.invalid_io); + bio_io_error(bio); + return 0; + } + + switch (bio_data_dir(bio)) { + case READ: + ret = ramzswap_read(rzs, bio); + break; + + case WRITE: + ret = ramzswap_write(rzs, bio); + break; + } + + return ret; +} + +static void reset_device(struct ramzswap *rzs) +{ + size_t index; + + /* Do not accept any new I/O request */ + rzs->init_done = 0; + + /* Free various per-device buffers */ + kfree(rzs->compress_workmem); + free_pages((unsigned long)rzs->compress_buffer, 1); + + rzs->compress_workmem = NULL; + rzs->compress_buffer = NULL; + + /* Free all pages that are still in this ramzswap device */ + for (index = 0; index < rzs->disksize >> PAGE_SHIFT; index++) { + struct page *page; + u16 offset; + + page = rzs->table[index].page; + offset = rzs->table[index].offset; + + if (!page) + continue; + + if (unlikely(rzs_test_flag(rzs, index, RZS_UNCOMPRESSED))) + __free_page(page); + else + xv_free(rzs->mem_pool, page, offset); + } + + vfree(rzs->table); + rzs->table = NULL; + + xv_destroy_pool(rzs->mem_pool); + rzs->mem_pool = NULL; + + /* Reset stats */ + memset(&rzs->stats, 0, sizeof(rzs->stats)); + + rzs->disksize = 0; +} + +static int ramzswap_ioctl_init_device(struct ramzswap *rzs) +{ + int ret; + size_t num_pages; + + if (rzs->init_done) { + pr_info("Device already initialized!\n"); + return -EBUSY; + } + + ramzswap_set_disksize(rzs, totalram_pages << PAGE_SHIFT); + + rzs->compress_workmem = kzalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL); + if (!rzs->compress_workmem) { + pr_err("Error allocating compressor working memory!\n"); + ret = -ENOMEM; + goto fail; + } + + rzs->compress_buffer = (void *)__get_free_pages(__GFP_ZERO, 1); + if (!rzs->compress_buffer) { + pr_err("Error allocating compressor buffer space\n"); + ret = -ENOMEM; + goto fail; + } + + num_pages = rzs->disksize >> PAGE_SHIFT; + rzs->table = vmalloc(num_pages * sizeof(*rzs->table)); + if (!rzs->table) { + pr_err("Error allocating ramzswap address table\n"); + /* To prevent accessing table entries during cleanup */ + rzs->disksize = 0; + ret = -ENOMEM; + goto fail; + } + memset(rzs->table, 0, num_pages * sizeof(*rzs->table)); + + set_capacity(rzs->disk, rzs->disksize >> SECTOR_SHIFT); + + /* ramzswap devices sort of resembles non-rotational disks */ + queue_flag_set_unlocked(QUEUE_FLAG_NONROT, rzs->disk->queue); + + rzs->mem_pool = xv_create_pool(); + if (!rzs->mem_pool) { + pr_err("Error creating memory pool\n"); + ret = -ENOMEM; + goto fail; + } + + rzs->init_done = 1; + + pr_debug("Initialization done!\n"); + return 0; + +fail: + reset_device(rzs); + + pr_err("Initialization failed: err=%d\n", ret); + return ret; +} + +static int ramzswap_ioctl_reset_device(struct ramzswap *rzs) +{ + if (rzs->init_done) + reset_device(rzs); + + return 0; +} + +static int ramzswap_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) +{ + int ret = 0; + size_t disksize_kb; + + struct ramzswap *rzs = bdev->bd_disk->private_data; + + switch (cmd) { + case RZSIO_SET_DISKSIZE_KB: + if (rzs->init_done) { + ret = -EBUSY; + goto out; + } + if (copy_from_user(&disksize_kb, (void *)arg, + _IOC_SIZE(cmd))) { + ret = -EFAULT; + goto out; + } + rzs->disksize = disksize_kb << 10; + pr_info("Disk size set to %zu kB\n", disksize_kb); + break; + + case RZSIO_GET_STATS: + { + struct ramzswap_ioctl_stats *stats; + if (!rzs->init_done) { + ret = -ENOTTY; + goto out; + } + stats = kzalloc(sizeof(*stats), GFP_KERNEL); + if (!stats) { + ret = -ENOMEM; + goto out; + } + ramzswap_ioctl_get_stats(rzs, stats); + if (copy_to_user((void *)arg, stats, sizeof(*stats))) { + kfree(stats); + ret = -EFAULT; + goto out; + } + kfree(stats); + break; + } + case RZSIO_INIT: + ret = ramzswap_ioctl_init_device(rzs); + break; + + case RZSIO_RESET: + /* Do not reset an active device! */ + if (bdev->bd_holders) { + ret = -EBUSY; + goto out; + } + + /* Make sure all pending I/O is finished */ + if (bdev) + fsync_bdev(bdev); + + ret = ramzswap_ioctl_reset_device(rzs); + break; + + default: + pr_info("Invalid ioctl %u\n", cmd); + ret = -ENOTTY; + } + +out: + return ret; +} + +void ramzswap_slot_free_notify(struct block_device *bdev, unsigned long index) +{ + struct ramzswap *rzs; + + rzs = bdev->bd_disk->private_data; + ramzswap_free_page(rzs, index); + rzs_stat64_inc(rzs, &rzs->stats.notify_free); +} + +static const struct block_device_operations ramzswap_devops = { + .ioctl = ramzswap_ioctl, + .swap_slot_free_notify = ramzswap_slot_free_notify, + .owner = THIS_MODULE +}; + +static int create_device(struct ramzswap *rzs, int device_id) +{ + int ret = 0; + + mutex_init(&rzs->lock); + spin_lock_init(&rzs->stat64_lock); + + rzs->queue = blk_alloc_queue(GFP_KERNEL); + if (!rzs->queue) { + pr_err("Error allocating disk queue for device %d\n", + device_id); + ret = -ENOMEM; + goto out; + } + + blk_queue_make_request(rzs->queue, ramzswap_make_request); + rzs->queue->queuedata = rzs; + + /* gendisk structure */ + rzs->disk = alloc_disk(1); + if (!rzs->disk) { + blk_cleanup_queue(rzs->queue); + pr_warning("Error allocating disk structure for device %d\n", + device_id); + ret = -ENOMEM; + goto out; + } + + rzs->disk->major = ramzswap_major; + rzs->disk->first_minor = device_id; + rzs->disk->fops = &ramzswap_devops; + rzs->disk->queue = rzs->queue; + rzs->disk->private_data = rzs; + snprintf(rzs->disk->disk_name, 16, "ramzswap%d", device_id); + + /* Actual capacity set using RZSIO_SET_DISKSIZE_KB ioctl */ + set_capacity(rzs->disk, 0); + + /* + * To ensure that we always get PAGE_SIZE aligned + * and n*PAGE_SIZED sized I/O requests. + */ + blk_queue_physical_block_size(rzs->disk->queue, PAGE_SIZE); + blk_queue_logical_block_size(rzs->disk->queue, PAGE_SIZE); + blk_queue_io_min(rzs->disk->queue, PAGE_SIZE); + blk_queue_io_opt(rzs->disk->queue, PAGE_SIZE); + + add_disk(rzs->disk); + + rzs->init_done = 0; + +out: + return ret; +} + +static void destroy_device(struct ramzswap *rzs) +{ + if (rzs->disk) { + del_gendisk(rzs->disk); + put_disk(rzs->disk); + } + + if (rzs->queue) + blk_cleanup_queue(rzs->queue); +} + +static int __init ramzswap_init(void) +{ + int ret, dev_id; + + if (num_devices > max_num_devices) { + pr_warning("Invalid value for num_devices: %u\n", + num_devices); + ret = -EINVAL; + goto out; + } + + ramzswap_major = register_blkdev(0, "ramzswap"); + if (ramzswap_major <= 0) { + pr_warning("Unable to get major number\n"); + ret = -EBUSY; + goto out; + } + + if (!num_devices) { + pr_info("num_devices not specified. Using default: 1\n"); + num_devices = 1; + } + + /* Allocate the device array and initialize each one */ + pr_info("Creating %u devices ...\n", num_devices); + devices = kzalloc(num_devices * sizeof(struct ramzswap), GFP_KERNEL); + if (!devices) { + ret = -ENOMEM; + goto unregister; + } + + for (dev_id = 0; dev_id < num_devices; dev_id++) { + ret = create_device(&devices[dev_id], dev_id); + if (ret) + goto free_devices; + } + + return 0; + +free_devices: + while (dev_id) + destroy_device(&devices[--dev_id]); +unregister: + unregister_blkdev(ramzswap_major, "ramzswap"); +out: + return ret; +} + +static void __exit ramzswap_exit(void) +{ + int i; + struct ramzswap *rzs; + + for (i = 0; i < num_devices; i++) { + rzs = &devices[i]; + + destroy_device(rzs); + if (rzs->init_done) + reset_device(rzs); + } + + unregister_blkdev(ramzswap_major, "ramzswap"); + + kfree(devices); + pr_debug("Cleanup done!\n"); +} + +module_param(num_devices, uint, 0); +MODULE_PARM_DESC(num_devices, "Number of ramzswap devices"); + +module_init(ramzswap_init); +module_exit(ramzswap_exit); + +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_AUTHOR("Nitin Gupta "); +MODULE_DESCRIPTION("Compressed RAM Based Swap Device"); diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h new file mode 100644 index 0000000..4d2e48a --- /dev/null +++ b/drivers/staging/zram/zram_drv.h @@ -0,0 +1,168 @@ +/* + * Compressed RAM based swap device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com + */ + +#ifndef _RAMZSWAP_DRV_H_ +#define _RAMZSWAP_DRV_H_ + +#include +#include + +#include "zram_ioctl.h" +#include "xvmalloc.h" + +/* + * Some arbitrary value. This is just to catch + * invalid value for num_devices module parameter. + */ +static const unsigned max_num_devices = 32; + +/* + * Stored at beginning of each compressed object. + * + * It stores back-reference to table entry which points to this + * object. This is required to support memory defragmentation. + */ +struct zobj_header { +#if 0 + u32 table_idx; +#endif +}; + +/*-- Configurable parameters */ + +/* Default ramzswap disk size: 25% of total RAM */ +static const unsigned default_disksize_perc_ram = 25; + +/* + * Pages that compress to size greater than this are stored + * uncompressed in memory. + */ +static const unsigned max_zpage_size = PAGE_SIZE / 4 * 3; + +/* + * NOTE: max_zpage_size must be less than or equal to: + * XV_MAX_ALLOC_SIZE - sizeof(struct zobj_header) + * otherwise, xv_malloc() would always return failure. + */ + +/*-- End of configurable params */ + +#define SECTOR_SHIFT 9 +#define SECTOR_SIZE (1 << SECTOR_SHIFT) +#define SECTORS_PER_PAGE_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) +#define SECTORS_PER_PAGE (1 << SECTORS_PER_PAGE_SHIFT) + +/* Flags for ramzswap pages (table[page_no].flags) */ +enum rzs_pageflags { + /* Page is stored uncompressed */ + RZS_UNCOMPRESSED, + + /* Page consists entirely of zeros */ + RZS_ZERO, + + __NR_RZS_PAGEFLAGS, +}; + +/*-- Data structures */ + +/* + * Allocated for each swap slot, indexed by page no. + * These table entries must fit exactly in a page. + */ +struct table { + struct page *page; + u16 offset; + u8 count; /* object ref count (not yet used) */ + u8 flags; +} __attribute__((aligned(4))); + +struct ramzswap_stats { + /* basic stats */ + size_t compr_size; /* compressed size of pages stored - + * needed to enforce memlimit */ + /* more stats */ +#if defined(CONFIG_RAMZSWAP_STATS) + u64 num_reads; /* failed + successful */ + u64 num_writes; /* --do-- */ + u64 failed_reads; /* should NEVER! happen */ + u64 failed_writes; /* can happen when memory is too low */ + u64 invalid_io; /* non-swap I/O requests */ + u64 notify_free; /* no. of swap slot free notifications */ + u32 pages_zero; /* no. of zero filled pages */ + u32 pages_stored; /* no. of pages currently stored */ + u32 good_compress; /* % of pages with compression ratio<=50% */ + u32 pages_expand; /* % of incompressible pages */ +#endif +}; + +struct ramzswap { + struct xv_pool *mem_pool; + void *compress_workmem; + void *compress_buffer; + struct table *table; + spinlock_t stat64_lock; /* protect 64-bit stats */ + struct mutex lock; /* protect compression buffers against + * concurrent writes */ + struct request_queue *queue; + struct gendisk *disk; + int init_done; + /* + * This is limit on amount of *uncompressed* worth of data + * we can hold. When backing swap device is provided, it is + * set equal to device size. + */ + size_t disksize; /* bytes */ + + struct ramzswap_stats stats; +}; + +/*-- */ + +/* Debugging and Stats */ +#if defined(CONFIG_RAMZSWAP_STATS) +static void rzs_stat_inc(u32 *v) +{ + *v = *v + 1; +} + +static void rzs_stat_dec(u32 *v) +{ + *v = *v - 1; +} + +static void rzs_stat64_inc(struct ramzswap *rzs, u64 *v) +{ + spin_lock(&rzs->stat64_lock); + *v = *v + 1; + spin_unlock(&rzs->stat64_lock); +} + +static u64 rzs_stat64_read(struct ramzswap *rzs, u64 *v) +{ + u64 val; + + spin_lock(&rzs->stat64_lock); + val = *v; + spin_unlock(&rzs->stat64_lock); + + return val; +} +#else +#define rzs_stat_inc(v) +#define rzs_stat_dec(v) +#define rzs_stat64_inc(r, v) +#define rzs_stat64_read(r, v) +#endif /* CONFIG_RAMZSWAP_STATS */ + +#endif diff --git a/drivers/staging/zram/zram_ioctl.h b/drivers/staging/zram/zram_ioctl.h new file mode 100644 index 0000000..db94bcb --- /dev/null +++ b/drivers/staging/zram/zram_ioctl.h @@ -0,0 +1,42 @@ +/* + * Compressed RAM based swap device + * + * Copyright (C) 2008, 2009, 2010 Nitin Gupta + * + * This code is released using a dual license strategy: BSD/GPL + * You can choose the licence that better fits your requirements. + * + * Released under the terms of 3-clause BSD License + * Released under the terms of GNU General Public License Version 2.0 + * + * Project home: http://compcache.googlecode.com + */ + +#ifndef _RAMZSWAP_IOCTL_H_ +#define _RAMZSWAP_IOCTL_H_ + +struct ramzswap_ioctl_stats { + u64 disksize; /* user specified or equal to backing swap + * size (if present) */ + u64 num_reads; /* failed + successful */ + u64 num_writes; /* --do-- */ + u64 failed_reads; /* should NEVER! happen */ + u64 failed_writes; /* can happen when memory is too low */ + u64 invalid_io; /* non-swap I/O requests */ + u64 notify_free; /* no. of swap slot free notifications */ + u32 pages_zero; /* no. of zero filled pages */ + u32 good_compress_pct; /* no. of pages with compression ratio<=50% */ + u32 pages_expand_pct; /* no. of incompressible pages */ + u32 pages_stored; + u32 pages_used; + u64 orig_data_size; + u64 compr_data_size; + u64 mem_used_total; +} __attribute__ ((packed, aligned(4))); + +#define RZSIO_SET_DISKSIZE_KB _IOW('z', 0, size_t) +#define RZSIO_GET_STATS _IOR('z', 1, struct ramzswap_ioctl_stats) +#define RZSIO_INIT _IO('z', 2) +#define RZSIO_RESET _IO('z', 3) + +#endif -- cgit v0.10.2