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* f2fs: avoid write_checkpoint if f2fs is mounted readonlyJaegeuk Kim2015-02-11
| | | | | | | Do not change any partition when f2fs is changed to readonly mode. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: support norecovery mount optionJaegeuk Kim2015-02-11
| | | | | | | | | | | | This patch adds a mount option, norecovery, which is mostly same as disable_roll_forward. The only difference is that norecovery should be activated with read-only mount option. This can be used when user wants to check whether f2fs is mountable or not without any recovery process. (e.g., xfstests/200) Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: fix not to drop mount options when retrying fill_superJaegeuk Kim2015-02-11
| | | | | | | | | If wrong mount option was requested, f2fs tries to fill_super again. But, during the next trial, f2fs has no valid mount options, since parse_options deleted all the separators in the original string. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: merge flags in struct f2fs_sb_infoChao Yu2015-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, there are several variables with Boolean type as below: struct f2fs_sb_info { ... int s_dirty; bool need_fsck; bool s_closing; ... bool por_doing; ... } For this there are some issues: 1. there are some space of f2fs_sb_info is wasted due to aligning after Boolean type variables by compiler. 2. if we continuously add new flag into f2fs_sb_info, structure will be messed up. So in this patch, we try to: 1. switch s_dirty to Boolean type variable since it has two status 0/1. 2. merge s_dirty/need_fsck/s_closing/por_doing variables into s_flag. 3. introduce an enum type which can indicate different states of sbi. 4. use new introduced universal interfaces is_sbi_flag_set/{set,clear}_sbi_flag to operate flags for sbi. After that, above issues will be fixed. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: clean up {in,de}create_sleep_timeChao Yu2015-02-11
| | | | | | | | Use pointer parameter @wait to pass result in {in,de}create_sleep_time for cleanup. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: make truncate_inline_date staticChao Yu2015-02-11
| | | | | | | | 1. make truncate_inline_date static; 2. remove parameter @from of truncate_inline_date as callers only pass zero. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: fix a bug of inheriting default ACL from parentKinglong Mee2015-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduced by a6dda0e63e97122ce9e0ba04367e37cca28315fa "f2fs: use generic posix ACL infrastructure". When testing default acl, gets in recent kernel (3.19.0-rc5), user::rwx group::r-x other::r-x default:user::rwx default:group::r-x default:group:root:rwx default:mask::rwx default:other::r-x ]# getfacl testdir/ user::rwx group::rwx // missing an acl "group:root:rwx" inherited from parent other::r-x default:user::rwx default:group::r-x default:group:root:rwx default:mask::rwx default:other::r-x Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: use f2fs_radix_tree_insert to clean codesChao Yu2015-02-11
| | | | | | | No modification in functionality, just clean codes with f2fs_radix_tree_insert. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: add F2FS_IOC_GETVERSION supportChao Yu2015-02-11
| | | | | | | | In this patch we add the FS_IOC_GETVERSION ioctl for getting i_generation from inode, after that, users can list file's generation number by using "lsattr -v". Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: leave comment for code readabilityJaegeuk Kim2015-02-11
| | | | | | | | During the recovery, any xattr blocks should not be found, since they are written into cold log, not the warm node chain. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: fix to release count of meta page in ->invalidatepageChao Yu2015-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We will encounter deadloop in below scenario: 1. increase page count for F2FS_DIRTY_META type in following path: ->recover_fsync_data ->recover_data ->do_recover_data ->recover_data_page ->change_curseg ->write_sum_page ->set_page_dirty 2. fail in recover_data() 3. invalidate meta pages in truncate_inode_pages_final without decreasing page count. 4. deadloop when sync_meta_pages as page count will always be non-zero. message: NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [<c1129a37>] pagevec_lookup_tag+0x27/0x30 [<f0e774c7>] sync_meta_pages+0x87/0x160 [f2fs] [<f0e86dd9>] recover_fsync_data+0xeb9/0xf10 [f2fs] [<f0e75398>] f2fs_fill_super+0x888/0x980 [f2fs] [<c11733ca>] mount_bdev+0x16a/0x1a0 [<f0e7180f>] f2fs_mount+0x1f/0x30 [f2fs] [<c1173da6>] mount_fs+0x36/0x170 [<c118b6f5>] vfs_kern_mount+0x55/0xe0 [<c118d63f>] do_mount+0x1df/0x9f0 [<c118e110>] SyS_mount+0x70/0xb0 [<c15a0c48>] sysenter_do_call+0x12/0x12 To avoid page count leak, let's add ->invalidatepage and ->releasepage in f2fs_meta_aops as f2fs_node_aops to release meta page count correctly. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: do checkpoint when umount flag is not setJaegeuk Kim2015-02-11
| | | | | | | | If the previous checkpoint was done without CP_UMOUNT flag, it needs to do checkpoint with CP_UMOUNT for the next fast boot. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: trigger correct checkpoint during umountJaegeuk Kim2015-02-11
| | | | | | | | | | | | This patch fixes to trigger checkpoint with umount flag when kill_sb was called. In kill_sb, f2fs_sync_fs was finally called, but at this time, f2fs can't do checkpoint with CP_UMOUNT. After then, f2fs_put_super is not doing checkpoint, since it is not dirty. So, this patch adds a flag to indicate f2fs_sync_fs is called during umount. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: update memory footprint informationJaegeuk Kim2015-02-11
| | | | | | This patch adds missing memory usages, and splits them in detail. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: fix wrong memory footprint statistics in debugfsChao Yu2015-02-11
| | | | | | | | Our value of memory footprint statistics showed in debugfs is not calculated correctly. Fix it in this patch. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: avoid infinite loop on cp_errorJaegeuk Kim2015-02-11
| | | | | | | If cp_error is set, we should avoid all the infinite loop. In f2fs_sync_file, there is a hole, and this patch fixes that. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: pids_lock can be statickbuild test robot2015-01-09
| | | | | | | fs/f2fs/trace.c:19:12: sparse: symbol 'pids_lock' was not declared. Should it be static? Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: add f2fs_destroy_trace_ios to free radix treeJaegeuk Kim2015-01-09
| | | | | | This patch removes radix tree after finishing tracing IOs. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: add spin_lock to cover radix operations in IO tracerJaegeuk Kim2015-01-09
| | | | | | This patch adds spin_lock to cover radix tree operations in IO tracer. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: add nat/sit entries into statusJaegeuk Kim2015-01-09
| | | | | | This patch adds NAT/SIT entry informations. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: free radix_tree_nodes used by nat_set entriesJaegeuk Kim2015-01-09
| | | | | | | In the normal case, the radix_tree_nodes are freed successfully. But, when cp_error was detected, we should destroy them forcefully. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: fix wrong unlock_page callJaegeuk Kim2015-01-09
| | | | | | This patch removes wrongly called unlock_page. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: get rid of kzalloc in __recover_inline_statusChao Yu2015-01-09
| | | | | | | | | | | We use kzalloc to allocate memory in __recover_inline_status, and use this all-zero memory to check the inline date content of inode page by comparing them. This is low effective and not needed, let's check inline date content directly. Signed-off-by: Chao Yu <chao2.yu@samsung.com> [Jaegeuk Kim: make the code more neat] Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: align direct_io'ed data to sectionJaegeuk Kim2015-01-09
| | | | | | | | | | | | | | This patch aligns the start block address of a file for direct io to the f2fs's section size. Some flash devices manage an over 4KB-sized page as a write unit, and if the direct_io'ed data are written but not aligned to that unit, the performance can be degraded due to the partial page copies. Thus, since f2fs has a section that is well aligned to FTL units, we can align the block address to the section size so that f2fs avoids this misalignment. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: remove uncovered code pathJaegeuk Kim2015-01-09
| | | | | | This patch removes unnecessary function calls. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: avoid potential unnecessary codesJaegeuk Kim2015-01-09
| | | | | | This patch relocates some operations to avoid unnecessary execution. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: clean up to remove parameterJaegeuk Kim2015-01-09
| | | | | | | This patch uses dn->data_blkaddr as a parameter for the destination block address. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: reuse inode_entry_slab in gc procedure for using slab more effectivelyChao Yu2015-01-09
| | | | | | | | | | | | | | | | | | | | | | | | | There are two slab cache inode_entry_slab and winode_slab using the same structure as below: struct dir_inode_entry { struct list_head list; /* list head */ struct inode *inode; /* vfs inode pointer */ }; struct inode_entry { struct list_head list; struct inode *inode; }; It's a little waste that the two cache can not share their memory space for each other. So in this patch we remove one redundant winode_slab slab cache, then use more universal name struct inode_entry as remaining data structure name of slab, finally we reuse the inode_entry_slab to store dirty dir item and gc item for more effective. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: cleanup parameters for ↵Chao Yu2015-01-09
| | | | | | | | | | | trace_f2fs_submit_{read_,write_,page_,page_m}bio with fio Cleanup parameters for trace_f2fs_submit_{read_,write_,page_,page_m}bio with fio as one parameter. Suggested-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: cleanup trace event of f2fs_submit_page_{m,}bio with DECLARE_EVENT_CLASSChao Yu2015-01-09
| | | | | | | | | | | | | | This patch adds missing parameter _type_ for trace_f2fs_submit_page_bio, then use DECLARE_EVENT_CLASS/DEFINE_EVENT_CONDITION pair to cleanup some trace event code related to f2fs_submit_page_{m,}bio. Additionally, after we remove redundant code, size of code can be reduced: text data bss dec hex filename 176787 8712 56 185555 2d4d3 f2fs.ko.org 174408 8648 56 183112 2cb48 f2fs.ko Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: fix missing cold bit during recoveryJaegeuk Kim2015-01-09
| | | | | | | | | | In do_recover_data, we find and update previous node pages after updating its new block addresses. After then, we call fill_node_footer without reset field, we erase its cold bit so that this new cold node block is written to wrong log area. This patch fixes not to miss its old flag. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: add block count by in-place-update in stat infoChangman Lee2015-01-09
| | | | | | | | This patch adds block count by in-place-update in stat. Signed-off-by: Changman Lee <cm224.lee@samsung.com> Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: avoid double lock for cp_rwsemJaegeuk Kim2015-01-09
| | | | | | | | | | | | | | | | | | The __f2fs_add_link is covered by cp_rwsem all the time. This calls init_inode_metadata, which conducts some acl operations including memory allocation with GFP_KERNEL previously. But, under memory pressure, f2fs_write_data_page can be called, which also grabs cp_rwsem too. In this case, this incurs a deadlock pointed by Chao. Thread #1 Thread #2 down_read down_write down_read -> here down_read should wait forever. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: activate f2fs_trace_iosJaegeuk Kim2015-01-09
| | | | | | This patch activates f2fs_trace_ios. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: activate f2fs_trace_pidJaegeuk Kim2015-01-09
| | | | | | This patch activates f2fs_trace_pid. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: add key functions for f2fs_io_tracerJaegeuk Kim2015-01-09
| | | | | | | | | | | This patch adds two key functions to trace process ids and IOs. The basic idea is to 1. remain process ids, pids, in page->private. 2. show pids in IO traces. So, later we can retrieve process information according to IO traces. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: add f2fs_io_tracer supportJaegeuk Kim2015-01-09
| | | | | | | | This patch adds: o initial trace.c and trace.h with skeleton functions o Kconfig and Makefile to activate this feature Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: use f2fs_io_info to clean up messy parameters during IO pathJaegeuk Kim2015-01-09
| | | | | | | | | This patch cleans up parameters on IO paths. The key idea is to use f2fs_io_info adding a parameter, block address, and then use this structure as parameters. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: use ra_meta_pages to simplify readahead code in restore_node_summaryChao Yu2015-01-09
| | | | | | | | | | | | | | | | Use more common function ra_meta_pages() with META_POR to readahead node blocks in restore_node_summary() instead of ra_sum_pages(), hence we can simplify the readahead code there, and also we can remove unused function ra_sum_pages(). changes from v2: o use invalidate_mapping_pages as before suggested by Changman Lee. changes from v1: o fix one bug when using truncate_inode_pages_range which is pointed out by Jaegeuk Kim. Reviewed-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: merge two uchar variable in struct node_info to reduce memory costChao Yu2015-01-09
| | | | | | | | | | | | | | | | | | | This patch moves one member of struct nat_entry: _flag_ to struct node_info, so _version_ in struct node_info and _flag_ which are unsigned char type will merge to one 32-bit space in register/memory. So the size of nat_entry will be reduced from 28 bytes to 24 bytes (for 64-bit machine, reduce its size from 40 bytes to 32 bytes) and then slab memory using by f2fs will be reduced. changes from v2: o update description of memory usage gain for 64-bit machine suggested by Changman Lee. changes from v1: o introduce inline copy_node_info() to copy valid data from node info suggested by Jaegeuk Kim, it can avoid bug. Reviewed-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: readahead contiguous current summary blocks in checkpointChao Yu2015-01-09
| | | | | | | | | | | Let's add readahead code for reading contiguous compact/normal summary blocks in checkpoint, then we will gain better performance in mount procedure. Changes from v1 o remove inappropriate 'unlikely' in npages_for_summary_flush. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: use missing the use of f2fs_kunmap_pageJaegeuk Kim2015-01-09
| | | | | | This patch calls f2fs_kunmap_page which I missed before. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: remove unnecessary call to invalidate inmemory pagesJaegeuk Kim2015-01-09
| | | | | | | Now we use inmemory pages for atomic write only and provide abort procedure, we don't need to truncate them explicitly. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: fix small discards not to issue redundantlyJaegeuk Kim2015-01-09
| | | | | | | | | | | The ckpt_valid_map and cur_valid_map are synced by seg_info_to_raw_sit. In the case of small discards, the candidates are selected before sync, while fitrim selects candidates after sync. So, for small discards, we need to add candidates only just being obsoleted. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: change atomic and volatile write policiesJaegeuk Kim2015-01-09
| | | | | | | | | | | | | | | This patch adds two new ioctls to release inmemory pages grabbed by atomic writes. o f2fs_ioc_abort_volatile_write - If transaction was failed, all the grabbed pages and data should be written. o f2fs_ioc_release_volatile_write - This is to enhance the performance of PERSIST mode in sqlite. In order to avoid huge memory consumption which causes OOM, this patch changes volatile writes to use normal dirty pages, instead blocked flushing to the disk as long as system does not suffer from memory pressure. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: don't need to call lock_op and lock_page for abortJaegeuk Kim2015-01-09
| | | | | | We don't need to call lock_op and lock_page at the aborting path. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: fix wrong condition check to trigger f2fs_sync_fsJaegeuk Kim2015-01-09
| | | | | | If there is not enough available memory, we need to trigger f2fs_sync_fs. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* f2fs: remove checking dirty_exceedJaegeuk Kim2015-01-09
| | | | | | | We don't need to force to write dirty_exceeded for f2fs_balance_fs_bg. This flag was only meaningful to write bypassing conditions. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2015-01-09
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc fixes from Andrew Morton: "12 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm, vmscan: prevent kswapd livelock due to pfmemalloc-throttled process being killed memcg: fix destination cgroup leak on task charges migration mm: memcontrol: switch soft limit default back to infinity mm/debug_pagealloc: remove obsolete Kconfig options vfs: renumber FMODE_NONOTIFY and add to uniqueness check arch/blackfin/mach-bf533/boards/stamp.c: add linux/delay.h ocfs2: fix the wrong directory passed to ocfs2_lookup_ino_from_name() when link file MAINTAINERS: update rydberg's addresses mm: protect set_page_dirty() from ongoing truncation mm: prevent endless growth of anon_vma hierarchy exit: fix race between wait_consider_task() and wait_task_zombie() ocfs2: remove bogus check in dlm_process_recovery_data
| * mm, vmscan: prevent kswapd livelock due to pfmemalloc-throttled process ↵Vlastimil Babka2015-01-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | being killed Charles Shirron and Paul Cassella from Cray Inc have reported kswapd stuck in a busy loop with nothing left to balance, but kswapd_try_to_sleep() failing to sleep. Their analysis found the cause to be a combination of several factors: 1. A process is waiting in throttle_direct_reclaim() on pgdat->pfmemalloc_wait 2. The process has been killed (by OOM in this case), but has not yet been scheduled to remove itself from the waitqueue and die. 3. kswapd checks for throttled processes in prepare_kswapd_sleep(): if (waitqueue_active(&pgdat->pfmemalloc_wait)) { wake_up(&pgdat->pfmemalloc_wait); return false; // kswapd will not go to sleep } However, for a process that was already killed, wake_up() does not remove the process from the waitqueue, since try_to_wake_up() checks its state first and returns false when the process is no longer waiting. 4. kswapd is running on the same CPU as the only CPU that the process is allowed to run on (through cpus_allowed, or possibly single-cpu system). 5. CONFIG_PREEMPT_NONE=y kernel is used. If there's nothing to balance, kswapd encounters no voluntary preemption points and repeatedly fails prepare_kswapd_sleep(), blocking the process from running and removing itself from the waitqueue, which would let kswapd sleep. So, the source of the problem is that we prevent kswapd from going to sleep until there are processes waiting on the pfmemalloc_wait queue, and a process waiting on a queue is guaranteed to be removed from the queue only when it gets scheduled. This was done to make sure that no process is left sleeping on pfmemalloc_wait when kswapd itself goes to sleep. However, it isn't necessary to postpone kswapd sleep until the pfmemalloc_wait queue actually empties. To prevent processes from being left sleeping, it's actually enough to guarantee that all processes waiting on pfmemalloc_wait queue have been woken up by the time we put kswapd to sleep. This patch therefore fixes this issue by substituting 'wake_up' with 'wake_up_all' and removing 'return false' in the code snippet from prepare_kswapd_sleep() above. Note that if any process puts itself in the queue after this waitqueue_active() check, or after the wake up itself, it means that the process will also wake up kswapd - and since we are under prepare_to_wait(), the wake up won't be missed. Also we update the comment prepare_kswapd_sleep() to hopefully more clearly describe the races it is preventing. Fixes: 5515061d22f0 ("mm: throttle direct reclaimers if PF_MEMALLOC reserves are low and swap is backed by network storage") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Rik van Riel <riel@redhat.com> Cc: <stable@vger.kernel.org> [3.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>