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2013-09-16Merge branch 'timers/core' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer code update from Thomas Gleixner: - armada SoC clocksource overhaul with a trivial merge conflict - Minor improvements to various SoC clocksource drivers * 'timers/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource: armada-370-xp: Add detailed clock requirements in devicetree binding clocksource: armada-370-xp: Get reference fixed-clock by name clocksource: armada-370-xp: Replace WARN_ON with BUG_ON clocksource: armada-370-xp: Fix device-tree binding clocksource: armada-370-xp: Introduce new compatibles clocksource: armada-370-xp: Use CLOCKSOURCE_OF_DECLARE clocksource: armada-370-xp: Simplify TIMER_CTRL register access clocksource: armada-370-xp: Use BIT() ARM: timer-sp: Set dynamic irq affinity ARM: nomadik: add dynamic irq flag to the timer clocksource: sh_cmt: 32-bit control register support clocksource: em_sti: Convert to devm_* managed helpers
2013-09-15Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds
Pull misc SCSI driver updates from James Bottomley: "This patch set is a set of driver updates (megaraid_sas, fnic, lpfc, ufs, hpsa) we also have a couple of bug fixes (sd out of bounds and ibmvfc error handling) and the first round of esas2r checker fixes and finally the much anticipated big endian additions for megaraid_sas" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (47 commits) [SCSI] fnic: fnic Driver Tuneables Exposed through CLI [SCSI] fnic: Kernel panic while running sh/nosh with max lun cfg [SCSI] fnic: Hitting BUG_ON(io_req->abts_done) in fnic_rport_exch_reset [SCSI] fnic: Remove QUEUE_FULL handling code [SCSI] fnic: On system with >1.1TB RAM, VIC fails multipath after boot up [SCSI] fnic: FC stat param seconds_since_last_reset not getting updated [SCSI] sd: Fix potential out-of-bounds access [SCSI] lpfc 8.3.42: Update lpfc version to driver version 8.3.42 [SCSI] lpfc 8.3.42: Fixed issue of task management commands having a fixed timeout [SCSI] lpfc 8.3.42: Fixed inconsistent spin lock usage. [SCSI] lpfc 8.3.42: Fix driver's abort loop functionality to skip IOs already getting aborted [SCSI] lpfc 8.3.42: Fixed failure to allocate SCSI buffer on PPC64 platform for SLI4 devices [SCSI] lpfc 8.3.42: Fix WARN_ON when driver unloads [SCSI] lpfc 8.3.42: Avoided making pci bar ioremap call during dual-chute WQ/RQ pci bar selection [SCSI] lpfc 8.3.42: Fixed driver iocbq structure's iocb_flag field running out of space [SCSI] lpfc 8.3.42: Fix crash on driver load due to cpu affinity logic [SCSI] lpfc 8.3.42: Fixed logging format of setting driver sysfs attributes hard to interpret [SCSI] lpfc 8.3.42: Fixed back to back RSCNs discovery failure. [SCSI] lpfc 8.3.42: Fixed race condition between BSG I/O dispatch and timeout handling [SCSI] lpfc 8.3.42: Fixed function mode field defined too small for not recognizing dual-chute mode ...
2013-09-15Merge branch 'slab/next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux Pull SLAB update from Pekka Enberg: "Nothing terribly exciting here apart from Christoph's kmalloc unification patches that brings sl[aou]b implementations closer to each other" * 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: slab: Use correct GFP_DMA constant slub: remove verify_mem_not_deleted() mm/sl[aou]b: Move kmallocXXX functions to common code mm, slab_common: add 'unlikely' to size check of kmalloc_slab() mm/slub.c: beautify code for removing redundancy 'break' statement. slub: Remove unnecessary page NULL check slub: don't use cpu partial pages on UP mm/slub: beautify code for 80 column limitation and tab alignment mm/slub: remove 'per_cpu' which is useless variable
2013-09-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input update from Dmitry Torokhov: "The only change is David Hermann's new EVIOCREVOKE evdev ioctl that allows safely passing file descriptors to input devices to session processes and later being able to stop delivery of events through these fds so that inactive sessions will no longer receive user input that does not belong to them" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: evdev - add EVIOCREVOKE ioctl
2013-09-14Merge tag 'writeback-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux Pull writeback fix from Wu Fengguang: "A trivial writeback fix" * tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: Do not sort b_io list only because of block device inode
2013-09-13Merge git://git.kvack.org/~bcrl/aio-nextLinus Torvalds
Pull aio changes from Ben LaHaise: "First off, sorry for this pull request being late in the merge window. Al had raised a couple of concerns about 2 items in the series below. I addressed the first issue (the race introduced by Gu's use of mm_populate()), but he has not provided any further details on how he wants to rework the anon_inode.c changes (which were sent out months ago but have yet to be commented on). The bulk of the changes have been sitting in the -next tree for a few months, with all the issues raised being addressed" * git://git.kvack.org/~bcrl/aio-next: (22 commits) aio: rcu_read_lock protection for new rcu_dereference calls aio: fix race in ring buffer page lookup introduced by page migration support aio: fix rcu sparse warnings introduced by ioctx table lookup patch aio: remove unnecessary debugging from aio_free_ring() aio: table lookup: verify ctx pointer staging/lustre: kiocb->ki_left is removed aio: fix error handling and rcu usage in "convert the ioctx list to table lookup v3" aio: be defensive to ensure request batching is non-zero instead of BUG_ON() aio: convert the ioctx list to table lookup v3 aio: double aio_max_nr in calculations aio: Kill ki_dtor aio: Kill ki_users aio: Kill unneeded kiocb members aio: Kill aio_rw_vect_retry() aio: Don't use ctx->tail unnecessarily aio: io_cancel() no longer returns the io_event aio: percpu ioctx refcount aio: percpu reqs_available aio: reqs_active -> reqs_available aio: fix build when migration is disabled ...
2013-09-13Remove GENERIC_HARDIRQ config optionMartin Schwidefsky
After the last architecture switched to generic hard irqs the config options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code for !CONFIG_GENERIC_HARDIRQS can be removed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-09-12Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending Pull SCSI target updates from Nicholas Bellinger: "Lots of activity again this round for I/O performance optimizations (per-cpu IDA pre-allocation for vhost + iscsi/target), and the addition of new fabric independent features to target-core (COMPARE_AND_WRITE + EXTENDED_COPY). The main highlights include: - Support for iscsi-target login multiplexing across individual network portals - Generic Per-cpu IDA logic (kent + akpm + clameter) - Conversion of vhost to use per-cpu IDA pre-allocation for descriptors, SGLs and userspace page pointer list - Conversion of iscsi-target + iser-target to use per-cpu IDA pre-allocation for descriptors - Add support for generic COMPARE_AND_WRITE (AtomicTestandSet) emulation for virtual backend drivers - Add support for generic EXTENDED_COPY (CopyOffload) emulation for virtual backend drivers. - Add support for fast memory registration mode to iser-target (Vu) The patches to add COMPARE_AND_WRITE and EXTENDED_COPY support are of particular significance, which make us the first and only open source target to support the full set of VAAI primitives. Currently Linux clients are lacking upstream support to actually utilize these primitives. However, with server side support now in place for folks like MKP + ZAB working on the client, this logic once reserved for the highest end of storage arrays, can now be run in VMs on their laptops" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (50 commits) target/iscsi: Bump versions to v4.1.0 target: Update copyright ownership/year information to 2013 iscsi-target: Bump default TCP listen backlog to 256 target: Fix >= v3.9+ regression in PR APTPL + ALUA metadata write-out iscsi-target; Bump default CmdSN Depth to 64 iscsi-target: Remove unnecessary wait_for_completion in iscsi_get_thread_set iscsi-target: Add thread_set->ts_activate_sem + use common deallocate iscsi-target: Fix race with thread_pre_handler flush_signals + ISCSI_THREAD_SET_DIE target: remove unused including <linux/version.h> iser-target: introduce fast memory registration mode (FRWR) iser-target: generalize rdma memory registration and cleanup iser-target: move rdma wr processing to a shared function target: Enable global EXTENDED_COPY setup/release target: Add Third Party Copy (3PC) bit in INQUIRY response target: Enable EXTENDED_COPY setup in spc_parse_cdb target: Add support for EXTENDED_COPY copy offload emulation target: Avoid non-existent tg_pt_gp_mem in target_alua_state_check target: Add global device list for EXTENDED_COPY target: Make helpers non static for EXTENDED_COPY command setup target: Make spc_parse_naa_6h_vendor_specific non static ...
2013-09-12Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge more patches from Andrew Morton: "The rest of MM. Plus one misc cleanup" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits) mm/Kconfig: add MMU dependency for MIGRATION. kernel: replace strict_strto*() with kstrto*() mm, thp: count thp_fault_fallback anytime thp fault fails thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page() thp: do_huge_pmd_anonymous_page() cleanup thp: move maybe_pmd_mkwrite() out of mk_huge_pmd() mm: cleanup add_to_page_cache_locked() thp: account anon transparent huge pages into NR_ANON_PAGES truncate: drop 'oldsize' truncate_pagecache() parameter mm: make lru_add_drain_all() selective memcg: document cgroup dirty/writeback memory statistics memcg: add per cgroup writeback pages accounting memcg: check for proper lock held in mem_cgroup_update_page_stat memcg: remove MEMCG_NR_FILE_MAPPED memcg: reduce function dereference memcg: avoid overflow caused by PAGE_ALIGN memcg: rename RESOURCE_MAX to RES_COUNTER_MAX memcg: correct RESOURCE_MAX to ULLONG_MAX mm: memcg: do not trap chargers with full callstack on OOM mm: memcg: rework and document OOM waiting and wakeup ...
2013-09-12thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page()Kirill A. Shutemov
do_huge_pmd_anonymous_page() has copy-pasted piece of handle_mm_fault() to handle fallback path. Let's consolidate code back by introducing VM_FAULT_FALLBACK return code. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12truncate: drop 'oldsize' truncate_pagecache() parameterKirill A. Shutemov
truncate_pagecache() doesn't care about old size since commit cedabed49b39 ("vfs: Fix vmtruncate() regression"). Let's drop it. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm: make lru_add_drain_all() selectiveChris Metcalf
make lru_add_drain_all() only selectively interrupt the cpus that have per-cpu free pages that can be drained. This is important in nohz mode where calling mlockall(), for example, otherwise will interrupt every core unnecessarily. This is important on workloads where nohz cores are handling 10 Gb traffic in userspace. Those CPUs do not enter the kernel and place pages into LRU pagevecs and they really, really don't want to be interrupted, or they drop packets on the floor. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: add per cgroup writeback pages accountingSha Zhengju
Add memcg routines to count writeback pages, later dirty pages will also be accounted. After Kame's commit 89c06bd52fb9 ("memcg: use new logic for page stat accounting"), we can use 'struct page' flag to test page state instead of per page_cgroup flag. But memcg has a feature to move a page from a cgroup to another one and may have race between "move" and "page stat accounting". So in order to avoid the race we have designed a new lock: mem_cgroup_begin_update_page_stat() modify page information -->(a) mem_cgroup_update_page_stat() -->(b) mem_cgroup_end_update_page_stat() It requires both (a) and (b)(writeback pages accounting) to be pretected in mem_cgroup_{begin/end}_update_page_stat(). It's full no-op for !CONFIG_MEMCG, almost no-op if memcg is disabled (but compiled in), rcu read lock in the most cases (no task is moving), and spin_lock_irqsave on top in the slow path. There're two writeback interfaces to modify: test_{clear/set}_page_writeback(). And the lock order is: --> memcg->move_lock --> mapping->tree_lock Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Greg Thelen <gthelen@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: remove MEMCG_NR_FILE_MAPPEDSha Zhengju
While accounting memcg page stat, it's not worth to use MEMCG_NR_FILE_MAPPED as an extra layer of indirection because of the complexity and presumed performance overhead. We can use MEM_CGROUP_STAT_FILE_MAPPED directly. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Reviewed-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: rename RESOURCE_MAX to RES_COUNTER_MAXSha Zhengju
RESOURCE_MAX is far too general name, change it to RES_COUNTER_MAX. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Jeff Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: correct RESOURCE_MAX to ULLONG_MAXSha Zhengju
Current RESOURCE_MAX is ULONG_MAX, but the value we used to set resource limit is unsigned long long, so we can set bigger value than that which is strange. The XXX_MAX should be reasonable max value, bigger than that should be overflow. Notice that this change will affect user output of default *.limit_in_bytes: before change: $ cat /cgroup/memory/memory.limit_in_bytes 9223372036854775807 after change: $ cat /cgroup/memory/memory.limit_in_bytes 18446744073709551615 But it doesn't alter the API in term of input - we can still use "echo -1 > *.limit_in_bytes" to reset the numbers to "unlimited". Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Jeff Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm: memcg: do not trap chargers with full callstack on OOMJohannes Weiner
The memcg OOM handling is incredibly fragile and can deadlock. When a task fails to charge memory, it invokes the OOM killer and loops right there in the charge code until it succeeds. Comparably, any other task that enters the charge path at this point will go to a waitqueue right then and there and sleep until the OOM situation is resolved. The problem is that these tasks may hold filesystem locks and the mmap_sem; locks that the selected OOM victim may need to exit. For example, in one reported case, the task invoking the OOM killer was about to charge a page cache page during a write(), which holds the i_mutex. The OOM killer selected a task that was just entering truncate() and trying to acquire the i_mutex: OOM invoking task: mem_cgroup_handle_oom+0x241/0x3b0 mem_cgroup_cache_charge+0xbe/0xe0 add_to_page_cache_locked+0x4c/0x140 add_to_page_cache_lru+0x22/0x50 grab_cache_page_write_begin+0x8b/0xe0 ext3_write_begin+0x88/0x270 generic_file_buffered_write+0x116/0x290 __generic_file_aio_write+0x27c/0x480 generic_file_aio_write+0x76/0xf0 # takes ->i_mutex do_sync_write+0xea/0x130 vfs_write+0xf3/0x1f0 sys_write+0x51/0x90 system_call_fastpath+0x18/0x1d OOM kill victim: do_truncate+0x58/0xa0 # takes i_mutex do_last+0x250/0xa30 path_openat+0xd7/0x440 do_filp_open+0x49/0xa0 do_sys_open+0x106/0x240 sys_open+0x20/0x30 system_call_fastpath+0x18/0x1d The OOM handling task will retry the charge indefinitely while the OOM killed task is not releasing any resources. A similar scenario can happen when the kernel OOM killer for a memcg is disabled and a userspace task is in charge of resolving OOM situations. In this case, ALL tasks that enter the OOM path will be made to sleep on the OOM waitqueue and wait for userspace to free resources or increase the group's limit. But a userspace OOM handler is prone to deadlock itself on the locks held by the waiting tasks. For example one of the sleeping tasks may be stuck in a brk() call with the mmap_sem held for writing but the userspace handler, in order to pick an optimal victim, may need to read files from /proc/<pid>, which tries to acquire the same mmap_sem for reading and deadlocks. This patch changes the way tasks behave after detecting a memcg OOM and makes sure nobody loops or sleeps with locks held: 1. When OOMing in a user fault, invoke the OOM killer and restart the fault instead of looping on the charge attempt. This way, the OOM victim can not get stuck on locks the looping task may hold. 2. When OOMing in a user fault but somebody else is handling it (either the kernel OOM killer or a userspace handler), don't go to sleep in the charge context. Instead, remember the OOMing memcg in the task struct and then fully unwind the page fault stack with -ENOMEM. pagefault_out_of_memory() will then call back into the memcg code to check if the -ENOMEM came from the memcg, and then either put the task to sleep on the memcg's OOM waitqueue or just restart the fault. The OOM victim can no longer get stuck on any lock a sleeping task may hold. Debugged by Michal Hocko. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: azurIt <azurit@pobox.sk> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm: memcg: enable memcg OOM killer only for user faultsJohannes Weiner
System calls and kernel faults (uaccess, gup) can handle an out of memory situation gracefully and just return -ENOMEM. Enable the memcg OOM killer only for user faults, where it's really the only option available. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12arch: mm: pass userspace fault flag to generic fault handlerJohannes Weiner
Unlike global OOM handling, memory cgroup code will invoke the OOM killer in any OOM situation because it has no way of telling faults occuring in kernel context - which could be handled more gracefully - from user-triggered faults. Pass a flag that identifies faults originating in user space from the architecture-specific fault handlers to generic code so that memcg OOM handling can be improved. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: enhance memcg iterator to support predicatesMichal Hocko
The caller of the iterator might know that some nodes or even subtrees should be skipped but there is no way to tell iterators about that so the only choice left is to let iterators to visit each node and do the selection outside of the iterating code. This, however, doesn't scale well with hierarchies with many groups where only few groups are interesting. This patch adds mem_cgroup_iter_cond variant of the iterator with a callback which gets called for every visited node. There are three possible ways how the callback can influence the walk. Either the node is visited, it is skipped but the tree walk continues down the tree or the whole subtree of the current group is skipped. [hughd@google.com: fix memcg-less page reclaim] Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@openvz.org> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ying Han <yinghan@google.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12vmscan, memcg: do softlimit reclaim also for targeted reclaimMichal Hocko
Soft reclaim has been done only for the global reclaim (both background and direct). Since "memcg: integrate soft reclaim tighter with zone shrinking code" there is no reason for this limitation anymore as the soft limit reclaim doesn't use any special code paths and it is a part of the zone shrinking code which is used by both global and targeted reclaims. From the semantic point of view it is natural to consider soft limit before touching all groups in the hierarchy tree which is touching the hard limit because soft limit tells us where to push back when there is a memory pressure. It is not important whether the pressure comes from the limit or imbalanced zones. This patch simply enables soft reclaim unconditionally in mem_cgroup_should_soft_reclaim so it is enabled for both global and targeted reclaim paths. mem_cgroup_soft_reclaim_eligible needs to learn about the root of the reclaim to know where to stop checking soft limit state of parents up the hierarchy. Say we have A (over soft limit) \ B (below s.l., hit the hard limit) / \ C D (below s.l.) B is the source of the outside memory pressure now for D but we shouldn't soft reclaim it because it is behaving well under B subtree and we can still reclaim from C (pressumably it is over the limit). mem_cgroup_soft_reclaim_eligible should therefore stop climbing up the hierarchy at B (root of the memory pressure). Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Glauber Costa <glommer@openvz.org> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg, vmscan: integrate soft reclaim tighter with zone shrinking codeMichal Hocko
This patchset is sitting out of tree for quite some time without any objections. I would be really happy if it made it into 3.12. I do not want to push it too hard but I think this work is basically ready and waiting more doesn't help. The basic idea is quite simple. Pull soft reclaim into shrink_zone in the first step and get rid of the previous soft reclaim infrastructure. shrink_zone is done in two passes now. First it tries to do the soft limit reclaim and it falls back to reclaim-all mode if no group is over the limit or no pages have been scanned. The second pass happens at the same priority so the only time we waste is the memcg tree walk which has been updated in the third step to have only negligible overhead. As a bonus we will get rid of a _lot_ of code by this and soft reclaim will not stand out like before when it wasn't integrated into the zone shrinking code and it reclaimed at priority 0 (the testing results show that some workloads suffers from such an aggressive reclaim). The clean up is in a separate patch because I felt it would be easier to review that way. The second step is soft limit reclaim integration into targeted reclaim. It should be rather straight forward. Soft limit has been used only for the global reclaim so far but it makes sense for any kind of pressure coming from up-the-hierarchy, including targeted reclaim. The third step (patches 4-8) addresses the tree walk overhead by enhancing memcg iterators to enable skipping whole subtrees and tracking number of over soft limit children at each level of the hierarchy. This information is updated same way the old soft limit tree was updated (from memcg_check_events) so we shouldn't see an additional overhead. In fact mem_cgroup_update_soft_limit is much simpler than tree manipulation done previously. __shrink_zone uses mem_cgroup_soft_reclaim_eligible as a predicate for mem_cgroup_iter so the decision whether a particular group should be visited is done at the iterator level which allows us to decide to skip the whole subtree as well (if there is no child in excess). This reduces the tree walk overhead considerably. * TEST 1 ======== My primary test case was a parallel kernel build with 2 groups (make is running with -j8 with a distribution .config in a separate cgroup without any hard limit) on a 32 CPU machine booted with 1GB memory and both builds run taskset to Node 0 cpus. I was mostly interested in 2 setups. Default - no soft limit set and - and 0 soft limit set to both groups. The first one should tell us whether the rework regresses the default behavior while the second one should show us improvements in an extreme case where both workloads are always over the soft limit. /usr/bin/time -v has been used to collect the statistics and each configuration had 3 runs after fresh boot without any other load on the system. base is mmotm-2013-07-18-16-40 rework all 8 patches applied on top of base * No-limit User no-limit/base: min: 651.92 max: 672.65 avg: 664.33 std: 8.01 runs: 6 no-limit/rework: min: 657.34 [100.8%] max: 668.39 [99.4%] avg: 663.13 [99.8%] std: 3.61 runs: 6 System no-limit/base: min: 69.33 max: 71.39 avg: 70.32 std: 0.79 runs: 6 no-limit/rework: min: 69.12 [99.7%] max: 71.05 [99.5%] avg: 70.04 [99.6%] std: 0.59 runs: 6 Elapsed no-limit/base: min: 398.27 max: 422.36 avg: 408.85 std: 7.74 runs: 6 no-limit/rework: min: 386.36 [97.0%] max: 438.40 [103.8%] avg: 416.34 [101.8%] std: 18.85 runs: 6 The results are within noise. Elapsed time has a bigger variance but the average looks good. * 0-limit User 0-limit/base: min: 573.76 max: 605.63 avg: 585.73 std: 12.21 runs: 6 0-limit/rework: min: 645.77 [112.6%] max: 666.25 [110.0%] avg: 656.97 [112.2%] std: 7.77 runs: 6 System 0-limit/base: min: 69.57 max: 71.13 avg: 70.29 std: 0.54 runs: 6 0-limit/rework: min: 68.68 [98.7%] max: 71.40 [100.4%] avg: 69.91 [99.5%] std: 0.87 runs: 6 Elapsed 0-limit/base: min: 1306.14 max: 1550.17 avg: 1430.35 std: 90.86 runs: 6 0-limit/rework: min: 404.06 [30.9%] max: 465.94 [30.1%] avg: 434.81 [30.4%] std: 22.68 runs: 6 The improvement is really huge here (even bigger than with my previous testing and I suspect that this highly depends on the storage). Page fault statistics tell us at least part of the story: Minor 0-limit/base: min: 37180461.00 max: 37319986.00 avg: 37247470.00 std: 54772.71 runs: 6 0-limit/rework: min: 36751685.00 [98.8%] max: 36805379.00 [98.6%] avg: 36774506.33 [98.7%] std: 17109.03 runs: 6 Major 0-limit/base: min: 170604.00 max: 221141.00 avg: 196081.83 std: 18217.01 runs: 6 0-limit/rework: min: 2864.00 [1.7%] max: 10029.00 [4.5%] avg: 5627.33 [2.9%] std: 2252.71 runs: 6 Same as with my previous testing Minor faults are more or less within noise but Major fault count is way bellow the base kernel. While this looks as a nice win it is fair to say that 0-limit configuration is quite artificial. So I was playing with 0-no-limit loads as well. * TEST 2 ======== The following results are from 2 groups configuration on a 16GB machine (single NUMA node). - A running stream IO (dd if=/dev/zero of=local.file bs=1024) with 2*TotalMem with 0 soft limit. - B running a mem_eater which consumes TotalMem-1G without any limit. The mem_eater consumes the memory in 100 chunks with 1s nap after each mmap+poppulate so that both loads have chance to fight for the memory. The expected result is that B shouldn't be reclaimed and A shouldn't see a big dropdown in elapsed time. User base: min: 2.68 max: 2.89 avg: 2.76 std: 0.09 runs: 3 rework: min: 3.27 [122.0%] max: 3.74 [129.4%] avg: 3.44 [124.6%] std: 0.21 runs: 3 System base: min: 86.26 max: 88.29 avg: 87.28 std: 0.83 runs: 3 rework: min: 81.05 [94.0%] max: 84.96 [96.2%] avg: 83.14 [95.3%] std: 1.61 runs: 3 Elapsed base: min: 317.28 max: 332.39 avg: 325.84 std: 6.33 runs: 3 rework: min: 281.53 [88.7%] max: 298.16 [89.7%] avg: 290.99 [89.3%] std: 6.98 runs: 3 System time improved slightly as well as Elapsed. My previous testing has shown worse numbers but this again seem to depend on the storage speed. My theory is that the writeback doesn't catch up and prio-0 soft reclaim falls into wait on writeback page too often in the base kernel. The patched kernel doesn't do that because the soft reclaim is done from the kswapd/direct reclaim context. This can be seen on the following graph nicely. The A's group usage_in_bytes regurarly drops really low very often. All 3 runs http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/stream.png resp. a detail of the single run http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/stream-one-run.png mem_eater seems to be doing better as well. It gets to the full allocation size faster as can be seen on the following graph: http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/mem_eater-one-run.png /proc/meminfo collected during the test also shows that rework kernel hasn't swapped that much (well almost not at all): base: max: 123900 K avg: 56388.29 K rework: max: 300 K avg: 128.68 K kswapd and direct reclaim statistics are of no use unfortunatelly because soft reclaim is not accounted properly as the counters are hidden by global_reclaim() checks in the base kernel. * TEST 3 ======== Another test was the same configuration as TEST2 except the stream IO was replaced by a single kbuild (16 parallel jobs bound to Node0 cpus same as in TEST1) and mem_eater allocated TotalMem-200M so kbuild had only 200MB left. Kbuild did better with the rework kernel here as well: User base: min: 860.28 max: 872.86 avg: 868.03 std: 5.54 runs: 3 rework: min: 880.81 [102.4%] max: 887.45 [101.7%] avg: 883.56 [101.8%] std: 2.83 runs: 3 System base: min: 84.35 max: 85.06 avg: 84.79 std: 0.31 runs: 3 rework: min: 85.62 [101.5%] max: 86.09 [101.2%] avg: 85.79 [101.2%] std: 0.21 runs: 3 Elapsed base: min: 135.36 max: 243.30 avg: 182.47 std: 45.12 runs: 3 rework: min: 110.46 [81.6%] max: 116.20 [47.8%] avg: 114.15 [62.6%] std: 2.61 runs: 3 Minor base: min: 36635476.00 max: 36673365.00 avg: 36654812.00 std: 15478.03 runs: 3 rework: min: 36639301.00 [100.0%] max: 36695541.00 [100.1%] avg: 36665511.00 [100.0%] std: 23118.23 runs: 3 Major base: min: 14708.00 max: 53328.00 avg: 31379.00 std: 16202.24 runs: 3 rework: min: 302.00 [2.1%] max: 414.00 [0.8%] avg: 366.33 [1.2%] std: 47.22 runs: 3 Again we can see a significant improvement in Elapsed (it also seems to be more stable), there is a huge dropdown for the Major page faults and much more swapping: base: max: 583736 K avg: 112547.43 K rework: max: 4012 K avg: 124.36 K Graphs from all three runs show the variability of the kbuild quite nicely. It even seems that it took longer after every run with the base kernel which would be quite surprising as the source tree for the build is removed and caches are dropped after each run so the build operates on a freshly extracted sources everytime. http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/kbuild-mem_eater.png My other testing shows that this is just a matter of timing and other runs behave differently the std for Elapsed time is similar ~50. Example of other three runs: http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/kbuild-mem_eater2.png So to wrap this up. The series is still doing good and improves the soft limit. The testing results for bunch of cgroups with both stream IO and kbuild loads can be found in "memcg: track children in soft limit excess to improve soft limit". This patch: Memcg soft reclaim has been traditionally triggered from the global reclaim paths before calling shrink_zone. mem_cgroup_soft_limit_reclaim then picked up a group which exceeds the soft limit the most and reclaimed it with 0 priority to reclaim at least SWAP_CLUSTER_MAX pages. The infrastructure requires per-node-zone trees which hold over-limit groups and keep them up-to-date (via memcg_check_events) which is not cost free. Although this overhead hasn't turned out to be a bottle neck the implementation is suboptimal because mem_cgroup_update_tree has no idea which zones consumed memory over the limit so we could easily end up having a group on a node-zone tree having only few pages from that node-zone. This patch doesn't try to fix node-zone trees management because it seems that integrating soft reclaim into zone shrinking sounds much easier and more appropriate for several reasons. First of all 0 priority reclaim was a crude hack which might lead to big stalls if the group's LRUs are big and hard to reclaim (e.g. a lot of dirty/writeback pages). Soft reclaim should be applicable also to the targeted reclaim which is awkward right now without additional hacks. Last but not least the whole infrastructure eats quite some code. After this patch shrink_zone is done in 2 passes. First it tries to do the soft reclaim if appropriate (only for global reclaim for now to keep compatible with the original state) and fall back to ignoring soft limit if no group is eligible to soft reclaim or nothing has been scanned during the first pass. Only groups which are over their soft limit or any of their parents up the hierarchy is over the limit are considered eligible during the first pass. Soft limit tree which is not necessary anymore will be removed in the follow up patch to make this patch smaller and easier to review. Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Glauber Costa <glommer@openvz.org> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ying Han <yinghan@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile 4 from Al Viro: "list_lru pile, mostly" This came out of Andrew's pile, Al ended up doing the merge work so that Andrew didn't have to. Additionally, a few fixes. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (42 commits) super: fix for destroy lrus list_lru: dynamically adjust node arrays shrinker: Kill old ->shrink API. shrinker: convert remaining shrinkers to count/scan API staging/lustre/libcfs: cleanup linux-mem.h staging/lustre/ptlrpc: convert to new shrinker API staging/lustre/obdclass: convert lu_object shrinker to count/scan API staging/lustre/ldlm: convert to shrinkers to count/scan API hugepage: convert huge zero page shrinker to new shrinker API i915: bail out earlier when shrinker cannot acquire mutex drivers: convert shrinkers to new count/scan API fs: convert fs shrinkers to new scan/count API xfs: fix dquot isolation hang xfs-convert-dquot-cache-lru-to-list_lru-fix xfs: convert dquot cache lru to list_lru xfs: rework buffer dispose list tracking xfs-convert-buftarg-lru-to-generic-code-fix xfs: convert buftarg LRU to generic code fs: convert inode and dentry shrinking to be node aware vmscan: per-node deferred work ...
2013-09-12Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds Pull led updates from Bryan Wu: "Sorry for the late pull request, since I'm just back from vacation. LED subsystem updates for 3.12: - pca9633 driver DT supporting and pca9634 chip supporting - restore legacy device attributes for lp5521 - other fixing and updates" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds: (28 commits) leds: wm831x-status: Request a REG resource leds: trigger: ledtrig-backlight: Fix invalid memory access in fb_event notification callback leds-pca963x: Fix device tree parsing leds-pca9633: Rename to leds-pca963x leds-pca9633: Add mutex to the ledout register leds-pca9633: Unique naming of the LEDs leds-pca9633: Add support for PCA9634 leds: lp5562: use LP55xx common macros for device attributes Documentation: leds-lp5521,lp5523: update device attribute information leds: lp5523: remove unnecessary writing commands leds: lp5523: restore legacy device attributes leds: lp5523: LED MUX configuration on initializing leds: lp5523: make separate API for loading engine leds: lp5521: remove unnecessary writing commands leds: lp5521: restore legacy device attributes leds: lp55xx: add common macros for device attributes leds: lp55xx: add common data structure for program Documentation: leds: Fix a typo leds: ss4200: Fix incorrect placement of __initdata leds: clevo-mail: Fix incorrect placement of __initdata ...
2013-09-12Merge tag 'iommu-updates-v3.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull IOMMU Updates from Joerg Roedel: "This round the updates contain: - A new driver for the Freescale PAMU IOMMU from Varun Sethi. This driver has cooked for a while and required changes to the IOMMU-API and infrastructure that were already merged before. - Updates for the ARM-SMMU driver from Will Deacon - Various fixes, the most important one is probably a fix from Alex Williamson for a memory leak in the VT-d page-table freeing code In summary not all that much. The biggest part in the diffstat is the new PAMU driver" * tag 'iommu-updates-v3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: intel-iommu: Fix leaks in pagetable freeing iommu/amd: Fix resource leak in iommu_init_device() iommu/amd: Clean up unnecessary MSI/MSI-X capability find iommu/arm-smmu: Simplify VMID and ASID allocation iommu/arm-smmu: Don't use VMIDs for stage-1 translations iommu/arm-smmu: Tighten up global fault reporting iommu/arm-smmu: Remove broken big-endian check iommu/fsl: Remove unnecessary 'fsl-pamu' prefixes iommu/fsl: Fix whitespace problems noticed by git-am iommu/fsl: Freescale PAMU driver and iommu implementation. iommu/fsl: Add additional iommu attributes required by the PAMU driver. powerpc: Add iommu domain pointer to device archdata iommu/exynos: Remove dead code (set_prefbuf)
2013-09-12Merge tag 'pm+acpi-fixes-3.12-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management fixes from Rafael Wysocki: "All of these commits are fixes that have emerged recently and some of them fix bugs introduced during this merge window. Specifics: 1) ACPI-based PCI hotplug (ACPIPHP) fixes related to spurious events After the recent ACPIPHP changes we've seen some interesting breakage on a system that triggers device check notifications during boot for non-existing devices. Although those notifications are really spurious, we should be able to deal with them nevertheless and that shouldn't introduce too much overhead. Four commits to make that work properly. 2) Memory hotplug and hibernation mutual exclusion rework This was maent to be a cleanup, but it happens to fix a classical ABBA deadlock between system suspend/hibernation and ACPI memory hotplug which is possible if they are started roughly at the same time. Three commits rework memory hotplug so that it doesn't acquire pm_mutex and make hibernation use device_hotplug_lock which prevents it from racing with memory hotplug. 3) ACPI Intel LPSS (Low-Power Subsystem) driver crash fix The ACPI LPSS driver crashes during boot on Apple Macbook Air with Haswell that has slightly unusual BIOS configuration in which one of the LPSS device's _CRS method doesn't return all of the information expected by the driver. Fix from Mika Westerberg, for stable. 4) ACPICA fix related to Store->ArgX operation AML interpreter fix for obscure breakage that causes AML to be executed incorrectly on some machines (observed in practice). From Bob Moore. 5) ACPI core fix for PCI ACPI device objects lookup There still are cases in which there is more than one ACPI device object matching a given PCI device and we don't choose the one that the BIOS expects us to choose, so this makes the lookup take more criteria into account in those cases. 6) Fix to prevent cpuidle from crashing in some rare cases If the result of cpuidle_get_driver() is NULL, which can happen on some systems, cpuidle_driver_ref() will crash trying to use that pointer and the Daniel Fu's fix prevents that from happening. 7) cpufreq fixes related to CPU hotplug Stephen Boyd reported a number of concurrency problems with cpufreq related to CPU hotplug which are addressed by a series of fixes from Srivatsa S Bhat and Viresh Kumar. 8) cpufreq fix for time conversion in time_in_state attribute Time conversion carried out by cpufreq when user space attempts to read /sys/devices/system/cpu/cpu*/cpufreq/stats/time_in_state won't work correcty if cputime_t doesn't map directly to jiffies. Fix from Andreas Schwab. 9) Revert of a troublesome cpufreq commit Commit 7c30ed5 (cpufreq: make sure frequency transitions are serialized) was intended to address some known concurrency problems in cpufreq related to the ordering of transitions, but unfortunately it introduced several problems of its own, so I decided to revert it now and address the original problems later in a more robust way. 10) Intel Haswell CPU models for intel_pstate from Nell Hardcastle. 11) cpufreq fixes related to system suspend/resume The recent cpufreq changes that made it preserve CPU sysfs attributes over suspend/resume cycles introduced a possible NULL pointer dereference that caused it to crash during the second attempt to suspend. Three commits from Srivatsa S Bhat fix that problem and a couple of related issues. 12) cpufreq locking fix cpufreq_policy_restore() should acquire the lock for reading, but it acquires it for writing. Fix from Lan Tianyu" * tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits) cpufreq: Acquire the lock in cpufreq_policy_restore() for reading cpufreq: Prevent problems in update_policy_cpu() if last_cpu == new_cpu cpufreq: Restructure if/else block to avoid unintended behavior cpufreq: Fix crash in cpufreq-stats during suspend/resume intel_pstate: Add Haswell CPU models Revert "cpufreq: make sure frequency transitions are serialized" cpufreq: Use signed type for 'ret' variable, to store negative error values cpufreq: Remove temporary fix for race between CPU hotplug and sysfs-writes cpufreq: Synchronize the cpufreq store_*() routines with CPU hotplug cpufreq: Invoke __cpufreq_remove_dev_finish() after releasing cpu_hotplug.lock cpufreq: Split __cpufreq_remove_dev() into two parts cpufreq: Fix wrong time unit conversion cpufreq: serialize calls to __cpufreq_governor() cpufreq: don't allow governor limits to be changed when it is disabled ACPI / bind: Prefer device objects with _STA to those without it ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks ACPI / hotplug / PCI: Use _OST to notify firmware about notify status ACPI / hotplug / PCI: Avoid doing too much for spurious notifies ACPICA: Fix for a Store->ArgX when ArgX contains a reference to a field. ACPI / hotplug / PCI: Don't trim devices before scanning the namespace ...
2013-09-12vfs: move get_fs_root_and_pwd() to single callerLinus Torvalds
Let's not pollute the include files with inline functions that are only used in a single place. Especially not if we decide we might want to change the semantics of said function to make it more efficient.. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "This is against 3.11-rc7, but was pulled and tested against your tree as of yesterday. We do have two small incrementals queued up, but I wanted to get this bunch out the door before I hop on an airplane. This is a fairly large batch of fixes, performance improvements, and cleanups from the usual Btrfs suspects. We've included Stefan Behren's work to index subvolume UUIDs, which is targeted at speeding up send/receive with many subvolumes or snapshots in place. It closes a long standing performance issue that was built in to the disk format. Mark Fasheh's offline dedup work is also here. In this case offline means the FS is mounted and active, but the dedup work is not done inline during file IO. This is a building block where utilities are able to ask the FS to dedup a series of extents. The kernel takes care of verifying the data involved really is the same. Today this involves reading both extents, but we'll continue to evolve the patches" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (118 commits) Btrfs: optimize key searches in btrfs_search_slot Btrfs: don't use an async starter for most of our workers Btrfs: only update disk_i_size as we remove extents Btrfs: fix deadlock in uuid scan kthread Btrfs: stop refusing the relocation of chunk 0 Btrfs: fix memory leak of uuid_root in free_fs_info btrfs: reuse kbasename helper btrfs: return btrfs error code for dev excl ops err Btrfs: allow partial ordered extent completion Btrfs: convert all bug_ons in free-space-cache.c Btrfs: add support for asserts Btrfs: adjust the fs_devices->missing count on unmount Btrf: cleanup: don't check for root_refs == 0 twice Btrfs: fix for patch "cleanup: don't check the same thing twice" Btrfs: get rid of one BUG() in write_all_supers() Btrfs: allocate prelim_ref with a slab allocater Btrfs: pass gfp_t to __add_prelim_ref() to avoid always using GFP_ATOMIC Btrfs: fix race conditions in BTRFS_IOC_FS_INFO ioctl Btrfs: fix race between removing a dev and writing sbs Btrfs: remove ourselves from the cluster list under lock ...
2013-09-12seqlock: Add a new locking reader typeWaiman Long
The sequence lock (seqlock) was originally designed for the cases where the readers do not need to block the writers by making the readers retry the read operation when the data change. Since then, the use cases have been expanded to include situations where a thread does not need to change the data (effectively a reader) at all but have to take the writer lock because it can't tolerate changes to the protected structure. Some examples are the d_path() function and the getcwd() syscall in fs/dcache.c where the functions take the writer lock on rename_lock even though they don't need to change anything in the protected data structure at all. This is inefficient as a reader is now blocking other sequence number reading readers from moving forward by pretending to be a writer. This patch tries to eliminate this inefficiency by introducing a new type of locking reader to the seqlock locking mechanism. This new locking reader will try to take an exclusive lock preventing other writers and locking readers from going forward. However, it won't affect the progress of the other sequence number reading readers as the sequence number won't be changed. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12Merge tag 'sound-3.12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound fixes from Takashi Iwai: "A few last-minute fixes for 3.12-rc1. All patches are driver specific. - HD-audio fixes: MacBook 6,1/6,2 speaker fix, ASUS TX300 dock speaker fix, Toshiba Satellite irq fix, Haswell HDMI audio cleanups) - ASoC fixes: atmel irq fix, fsl DT fix, mc13783 spi fix, kirkwood compatible string change, etc" * tag 'sound-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ASoC: mc13783: add spi errata fix ASoC: rsnd: fixup flag name of rsnd_scu_platform_info ALSA: hda - Add CS4208 codec support for MacBook 6,1 and 6,2 ALSA: hda - Add Toshiba Satellite C870 to MSI blacklist ASoC: fsl_spdif: Select regmap-mmio ALSA: hda - unmute pin amplifier in infoframe setup for Haswell ALSA: hda - define is_haswell() to check if a display audio codec is Haswell ALSA: hda - Add dock speaker support for ASUS TX300 ASoC: kirkwood: change the compatible string of the kirkwood-i2s driver ASoC: atmel: disable error interrupt ASoC: fsl: imx-audmux: Do not call imx_audmux_parse_dt_defaults() on non-dt kernel
2013-09-12Merge branches 'arm/exynos', 'ppc/pamu', 'arm/smmu', 'x86/amd' and ↵Joerg Roedel
'iommu/fixes' into next
2013-09-12Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux Pull thermal management updates from Zhang Rui: "We have a lot of SOC changes and a few thermal core fixes this time. The biggest change is about exynos thermal driver restructure. The patch set adds TMU (Thermal management Unit) driver support for exynos5440 platform. There are 3 instances of the TMU controllers so necessary cleanup/re-structure is done to handle multiple thermal zone. The next biggest change is the introduction of the imx thermal driver. It adds the imx thermal support using Temperature Monitor (TEMPMON) block found on some Freescale i.MX SoCs. The driver uses syscon regmap interface to access TEMPMON control registers and calibration data, and supports cpufreq as the cooling device. Highlights: - restructure exynos thermal driver. - introduce new imx thermal driver. - fix a bug in thermal core, which powers on the fans unexpectedly after resume from suspend" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux: (46 commits) drivers: thermal: add check when unregistering cpu cooling thermal: thermal_core: allow binding with limits on bind_params drivers: thermal: make usage of CONFIG_THERMAL_HWMON optional drivers: thermal: parent virtual hwmon with thermal zone thermal: hwmon: move hwmon support to single file thermal: exynos: Clean up non-DT remnants thermal: exynos: Fix potential NULL pointer dereference thermal: exynos: Fix typos in Kconfig thermal: ti-soc-thermal: Ensure to compute thermal trend thermal: ti-soc-thermal: Set the bandgap mask counter delay value thermal: ti-soc-thermal: Initialize counter_delay field for TI DRA752 sensors thermal: step_wise: return instance->target by default thermal: step_wise: cdev only needs update on a new target state Thermal/cpu_cooling: Return directly for the cpu out of allowed_cpus in the cpufreq_thermal_notifier() thermal: exynos_tmu: fix wrong error check for mapped memory thermal: imx: implement thermal alarm interrupt handling thermal: imx: dynamic passive and SoC specific critical trip points Documentation: thermal: Explain the exynos thermal driver model ARM: dts: thermal: exynos: Add documentation for Exynos SoC thermal bindings thermal: exynos: Support for TMU regulator defined at device tree ...
2013-09-12Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull CIFS fixes from Steve French: "CIFS update including case insensitive file name matching improvements for UTF-8 to Unicode, various small cifs fixes, SMB2/SMB3 leasing improvements, support for following SMB2 symlinks, SMB3 packet signing improvements" * 'for-next' of git://git.samba.org/sfrench/cifs-2.6: (25 commits) CIFS: Respect epoch value from create lease context v2 CIFS: Add create lease v2 context for SMB3 CIFS: Move parsing lease buffer to ops struct CIFS: Move creating lease buffer to ops struct CIFS: Store lease state itself rather than a mapped oplock value CIFS: Replace clientCanCache* bools with an integer [CIFS] quiet sparse compile warning cifs: Start using per session key for smb2/3 for signature generation cifs: Add a variable specific to NTLMSSP for key exchange. cifs: Process post session setup code in respective dialect functions. CIFS: convert to use le32_add_cpu() CIFS: Fix missing lease break CIFS: Fix a memory leak when a lease break comes cifs: add winucase_convert.pl to Documentation/ directory cifs: convert case-insensitive dentry ops to use new case conversion routines cifs: add new case-insensitive conversion routines that are based on wchar_t's [CIFS] Add Scott to list of cifs contributors cifs: Move and expand MAX_SERVER_SIZE definition cifs: Expand max share name length to 256 cifs: Move string length definitions to uapi ...
2013-09-11Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge first patch-bomb from Andrew Morton: - Some pidns/fork/exec tweaks - OCFS2 updates - Most of MM - there remain quite a few memcg parts which depend on pending core cgroups changes. Which might have been already merged - I'll check tomorrow... - Various misc stuff all over the place - A few block bits which I never got around to sending to Jens - relatively minor things. - MAINTAINERS maintenance - A small number of lib/ updates - checkpatch updates - epoll - firmware/dmi-scan - Some kprobes work for S390 - drivers/rtc updates - hfsplus feature work - vmcore feature work - rbtree upgrades - AOE updates - pktcdvd cleanups - PPS - memstick - w1 - New "inittmpfs" feature, which does the obvious - More IPC work from Davidlohr. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (303 commits) lz4: fix compression/decompression signedness mismatch ipc: drop ipc_lock_check ipc, shm: drop shm_lock_check ipc: drop ipc_lock_by_ptr ipc, shm: guard against non-existant vma in shmdt(2) ipc: document general ipc locking scheme ipc,msg: drop msg_unlock ipc: rename ids->rw_mutex ipc,shm: shorten critical region for shmat ipc,shm: cleanup do_shmat pasta ipc,shm: shorten critical region for shmctl ipc,shm: make shmctl_nolock lockless ipc,shm: introduce shmctl_nolock ipc: drop ipcctl_pre_down ipc,shm: shorten critical region in shmctl_down ipc,shm: introduce lockless functions to obtain the ipc object initmpfs: use initramfs if rootfstype= or root= specified initmpfs: make rootfs use tmpfs when CONFIG_TMPFS enabled initmpfs: move rootfs code from fs/ramfs/ to init/ initmpfs: move bdi setup from init_rootfs to init_ramfs ...
2013-09-11lz4: fix compression/decompression signedness mismatchSergey Senozhatsky
LZ4 compression and decompression functions require different in signedness input/output parameters: unsigned char for compression and signed char for decompression. Change decompression API to require "(const) unsigned char *". Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Kyungsik Lee <kyungsik.lee@lge.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Yann Collet <yann.collet.73@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11ipc: rename ids->rw_mutexDavidlohr Bueso
Since in some situations the lock can be shared for readers, we shouldn't be calling it a mutex, rename it to rwsem. Signed-off-by: Davidlohr Bueso <davidlohr.bueso@hp.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11initmpfs: move rootfs code from fs/ramfs/ to init/Rob Landley
When the rootfs code was a wrapper around ramfs, having them in the same file made sense. Now that it can wrap another filesystem type, move it in with the init code instead. This also allows a subsequent patch to access rootfstype= command line arg. Signed-off-by: Rob Landley <rob@landley.net> Cc: Jeff Layton <jlayton@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Stephen Warren <swarren@nvidia.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jim Cromie <jim.cromie@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11lib/radix-tree.c: make radix_tree_node_alloc() work correctly within interruptJan Kara
With users of radix_tree_preload() run from interrupt (block/blk-ioc.c is one such possible user), the following race can happen: radix_tree_preload() ... radix_tree_insert() radix_tree_node_alloc() if (rtp->nr) { ret = rtp->nodes[rtp->nr - 1]; <interrupt> ... radix_tree_preload() ... radix_tree_insert() radix_tree_node_alloc() if (rtp->nr) { ret = rtp->nodes[rtp->nr - 1]; And we give out one radix tree node twice. That clearly results in radix tree corruption with different results (usually OOPS) depending on which two users of radix tree race. We fix the problem by making radix_tree_node_alloc() always allocate fresh radix tree nodes when in interrupt. Using preloading when in interrupt doesn't make sense since all the allocations have to be atomic anyway and we cannot steal nodes from process-context users because some users rely on radix_tree_insert() succeeding after radix_tree_preload(). in_interrupt() check is somewhat ugly but we cannot simply key off passed gfp_mask as that is acquired from root_gfp_mask() and thus the same for all preload users. Another part of the fix is to avoid node preallocation in radix_tree_preload() when passed gfp_mask doesn't allow waiting. Again, preallocation in such case doesn't make sense and when preallocation would happen in interrupt we could possibly leak some allocated nodes. However, some users of radix_tree_preload() require following radix_tree_insert() to succeed. To avoid unexpected effects for these users, radix_tree_preload() only warns if passed gfp mask doesn't allow waiting and we provide a new function radix_tree_maybe_preload() for those users which get different gfp mask from different call sites and which are prepared to handle radix_tree_insert() failure. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11rbtree: add rbtree_postorder_for_each_entry_safe() helperCody P Schafer
Because deletion (of the entire tree) is a relatively common use of the rbtree_postorder iteration, and because doing it safely means fiddling with temporary storage, provide a helper to simplify postorder rbtree iteration. Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Reviewed-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: David Woodhouse <David.Woodhouse@intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11rbtree: add postorder iteration functionsCody P Schafer
Postorder iteration yields all of a node's children prior to yielding the node itself, and this particular implementation also avoids examining the leaf links in a node after that node has been yielded. In what I expect will be its most common usage, postorder iteration allows the deletion of every node in an rbtree without modifying the rbtree nodes (no _requirement_ that they be nulled) while avoiding referencing child nodes after they have been "deleted" (most commonly, freed). I have only updated zswap to use this functionality at this point, but numerous bits of code (most notably in the filesystem drivers) use a hand rolled postorder iteration that NULLs child links as it traverses the tree. Each of those instances could be replaced with this common implementation. 1 & 2 add rbtree postorder iteration functions. 3 adds testing of the iteration to the rbtree runtime tests 4 allows building the rbtree runtime tests as builtins 5 updates zswap. This patch: Add postorder iteration functions for rbtree. These are useful for safely freeing an entire rbtree without modifying the tree at all. Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Reviewed-by: Seth Jennings <sjenning@linux.vnet.ibm.com> Cc: David Woodhouse <David.Woodhouse@intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11vmcore: introduce remap_oldmem_pfn_range()Michael Holzheu
For zfcpdump we can't map the HSA storage because it is only available via a read interface. Therefore, for the new vmcore mmap feature we have introduce a new mechanism to create mappings on demand. This patch introduces a new architecture function remap_oldmem_pfn_range() that should be used to create mappings with remap_pfn_range() for oldmem areas that can be directly mapped. For zfcpdump this is everything besides of the HSA memory. For the areas that are not mapped by remap_oldmem_pfn_range() a generic vmcore a new generic vmcore fault handler mmap_vmcore_fault() is called. This handler works as follows: * Get already available or new page from page cache (find_or_create_page) * Check if /proc/vmcore page is filled with data (PageUptodate) * If yes: Return that page * If no: Fill page using __vmcore_read(), set PageUptodate, and return page Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Jan Willeke <willeke@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11vmcore: introduce ELF header in new memory featureMichael Holzheu
For s390 we want to use /proc/vmcore for our SCSI stand-alone dump (zfcpdump). We have support where the first HSA_SIZE bytes are saved into a hypervisor owned memory area (HSA) before the kdump kernel is booted. When the kdump kernel starts, it is restricted to use only HSA_SIZE bytes. The advantages of this mechanism are: * No crashkernel memory has to be defined in the old kernel. * Early boot problems (before kexec_load has been done) can be dumped * Non-Linux systems can be dumped. We modify the s390 copy_oldmem_page() function to read from the HSA memory if memory below HSA_SIZE bytes is requested. Since we cannot use the kexec tool to load the kernel in this scenario, we have to build the ELF header in the 2nd (kdump/new) kernel. So with the following patch set we would like to introduce the new function that the ELF header for /proc/vmcore can be created in the 2nd kernel memory. The following steps are done during zfcpdump execution: 1. Production system crashes 2. User boots a SCSI disk that has been prepared with the zfcpdump tool 3. Hypervisor saves CPU state of boot CPU and HSA_SIZE bytes of memory into HSA 4. Boot loader loads kernel into low memory area 5. Kernel boots and uses only HSA_SIZE bytes of memory 6. Kernel saves registers of non-boot CPUs 7. Kernel does memory detection for dump memory map 8. Kernel creates ELF header for /proc/vmcore 9. /proc/vmcore uses this header for initialization 10. The zfcpdump user space reads /proc/vmcore to write dump to SCSI disk - copy_oldmem_page() copies from HSA for memory below HSA_SIZE - copy_oldmem_page() copies from real memory for memory above HSA_SIZE Currently for s390 we create the ELF core header in the 2nd kernel with a small trick. We relocate the addresses in the ELF header in a way that for the /proc/vmcore code it seems to be in the 1st kernel (old) memory and the read_from_oldmem() returns the correct data. This allows the /proc/vmcore code to use the ELF header in the 2nd kernel. This patch: Exchange the old mechanism with the new and much cleaner function call override feature that now offcially allows to create the ELF core header in the 2nd kernel. To use the new feature the following function have to be defined by the architecture backend code to read from new memory: * elfcorehdr_alloc: Allocate ELF header * elfcorehdr_free: Free the memory of the ELF header * elfcorehdr_read: Read from ELF header * elfcorehdr_read_notes: Read from ELF notes Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Jan Willeke <willeke@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11exec: kill "int depth" in search_binary_handler()Oleg Nesterov
Nobody except search_binary_handler() should touch ->recursion_depth, "int depth" buys nothing but complicates the code, kill it. Probably we should also kill "fn" and the !NULL check, ->load_binary should be always defined. And it can not go away after read_unlock() or this code is buggy anyway. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Zach Levis <zml@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11kprobes: allow to specify custom allocator for insn cachesHeiko Carstens
The current two insn slot caches both use module_alloc/module_free to allocate and free insn slot cache pages. For s390 this is not sufficient since there is the need to allocate insn slots that are either within the vmalloc module area or within dma memory. Therefore add a mechanism which allows to specify an own allocator for an own insn slot cache. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11kprobes: unify insn cachesHeiko Carstens
The current kpropes insn caches allocate memory areas for insn slots with module_alloc(). The assumption is that the kernel image and module area are both within the same +/- 2GB memory area. This however is not true for s390 where the kernel image resides within the first 2GB (DMA memory area), but the module area is far away in the vmalloc area, usually somewhere close below the 4TB area. For new pc relative instructions s390 needs insn slots that are within +/- 2GB of each area. That way we can patch displacements of pc-relative instructions within the insn slots just like x86 and powerpc. The module area works already with the normal insn slot allocator, however there is currently no way to get insn slots that are within the first 2GB on s390 (aka DMA area). Therefore this patch set modifies the kprobes insn slot cache code in order to allow to specify a custom allocator for the insn slot cache pages. In addition architecure can now have private insn slot caches withhout the need to modify common code. Patch 1 unifies and simplifies the current insn and optinsn caches implementation. This is a preparation which allows to add more insn caches in a simple way. Patch 2 adds the possibility to specify a custom allocator. Patch 3 makes s390 use the new insn slot mechanisms and adds support for pc-relative instructions with long displacements. This patch (of 3): The two insn caches (insn, and optinsn) each have an own mutex and alloc/free functions (get_[opt]insn_slot() / free_[opt]insn_slot()). Since there is the need for yet another insn cache which satifies dma allocations on s390, unify and simplify the current implementation: - Move the per insn cache mutex into struct kprobe_insn_cache. - Move the alloc/free functions to kprobe.h so they are simply wrappers for the generic __get_insn_slot/__free_insn_slot functions. The implementation is done with a DEFINE_INSN_CACHE_OPS() macro which provides the alloc/free functions for each cache if needed. - move the struct kprobe_insn_cache to kprobe.h which allows to generate architecture specific insn slot caches outside of the core kprobes code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11syscalls.h: add forward declarations for inplace syscall wrappersSergei Trofimovich
Unclutter -Wmissing-prototypes warning types (enabled at make W=1) linux/include/linux/syscalls.h:190:18: warning: no previous prototype for 'SyS_semctl' [-Wmissing-prototypes] asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ ^ linux/include/linux/syscalls.h:183:2: note: in expansion of macro '__SYSCALL_DEFINEx' __SYSCALL_DEFINEx(x, sname, __VA_ARGS__) ^ by adding forward declarations right before definitions. Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11smp.h: move !SMP version of on_each_cpu() out-of-lineDavid Daney
All of the other non-trivial !SMP versions of functions in smp.h are out-of-line in up.c. Move on_each_cpu() there as well. This allows us to get rid of the #include <linux/irqflags.h>. The drawback is that this makes both the x86_64 and i386 defconfig !SMP kernels about 200 bytes larger each. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11smp: quit unconditionally enabling irq in on_each_cpu_mask and on_each_cpu_condDavid Daney
As in commit f21afc25f9ed ("smp.h: Use local_irq_{save,restore}() in !SMP version of on_each_cpu()"), we don't want to enable irqs if they are not already enabled. There are currently no known problematical callers of these functions, but since it is a known failure pattern, we preemptively fix them. Since they are not trivial functions, make them non-inline by moving them to up.c. This also makes it so we don't have to fix #include dependancies for preempt_{disable,enable}. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm/hwpoison: don't need to hold compound lock for hugetlbfs pageWanpeng Li
compound lock is introduced by commit e9da73d67("thp: compound_lock."), it is used to serialize put_page against __split_huge_page_refcount(). In addition, transparent hugepages will be splitted in hwpoison handler and just one subpage will be poisoned. There is unnecessary to hold compound lock for hugetlbfs page. This patch replace compound_trans_order by compond_order in the place where the page is hugetlbfs page. Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11mm/page-writeback.c: add strictlimit featureMaxim Patlasov
The feature prevents mistrusted filesystems (ie: FUSE mounts created by unprivileged users) to grow a large number of dirty pages before throttling. For such filesystems balance_dirty_pages always check bdi counters against bdi limits. I.e. even if global "nr_dirty" is under "freerun", it's not allowed to skip bdi checks. The only use case for now is fuse: it sets bdi max_ratio to 1% by default and system administrators are supposed to expect that this limit won't be exceeded. The feature is on if a BDI is marked by BDI_CAP_STRICTLIMIT flag. A filesystem may set the flag when it initializes its BDI. The problematic scenario comes from the fact that nobody pays attention to the NR_WRITEBACK_TEMP counter (i.e. number of pages under fuse writeback). The implementation of fuse writeback releases original page (by calling end_page_writeback) almost immediately. A fuse request queued for real processing bears a copy of original page. Hence, if userspace fuse daemon doesn't finalize write requests in timely manner, an aggressive mmap writer can pollute virtually all memory by those temporary fuse page copies. They are carefully accounted in NR_WRITEBACK_TEMP, but nobody cares. To make further explanations shorter, let me use "NR_WRITEBACK_TEMP problem" as a shortcut for "a possibility of uncontrolled grow of amount of RAM consumed by temporary pages allocated by kernel fuse to process writeback". The problem was very easy to reproduce. There is a trivial example filesystem implementation in fuse userspace distribution: fusexmp_fh.c. I added "sleep(1);" to the write methods, then recompiled and mounted it. Then created a huge file on the mount point and run a simple program which mmap-ed the file to a memory region, then wrote a data to the region. An hour later I observed almost all RAM consumed by fuse writeback. Since then some unrelated changes in kernel fuse made it more difficult to reproduce, but it is still possible now. Putting this theoretical happens-in-the-lab thing aside, there is another thing that really hurts real world (FUSE) users. This is write-through page cache policy FUSE currently uses. I.e. handling write(2), kernel fuse populates page cache and flushes user data to the server synchronously. This is excessively suboptimal. Pavel Emelyanov's patches ("writeback cache policy") solve the problem, but they also make resolving NR_WRITEBACK_TEMP problem absolutely necessary. Otherwise, simply copying a huge file to a fuse mount would result in memory starvation. Miklos, the maintainer of FUSE, believes strictlimit feature the way to go. And eventually putting FUSE topics aside, there is one more use-case for strictlimit feature. Using a slow USB stick (mass storage) in a machine with huge amount of RAM installed is a well-known pain. Let's make simple computations. Assuming 64GB of RAM installed, existing implementation of balance_dirty_pages will start throttling only after 9.6GB of RAM becomes dirty (freerun == 15% of total RAM). So, the command "cp 9GB_file /media/my-usb-storage/" may return in a few seconds, but subsequent "umount /media/my-usb-storage/" will take more than two hours if effective throughput of the storage is, to say, 1MB/sec. After inclusion of strictlimit feature, it will be trivial to add a knob (e.g. /sys/devices/virtual/bdi/x:y/strictlimit) to enable it on demand. Manually or via udev rule. May be I'm wrong, but it seems to be quite a natural desire to limit the amount of dirty memory for some devices we are not fully trust (in the sense of sustainable throughput). [akpm@linux-foundation.org: fix warning in page-writeback.c] Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com> Cc: Jan Kara <jack@suse.cz> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>