Mel Gorman 283aba9f9e mm: vmscan: block kswapd if it is encountering pages under writeback ... Historically, kswapd used to congestion_wait() at higher priorities if it was not making forward progress. This made no sense as the failure to make progress could be completely independent of IO. It was later replaced by wait_iff_congested() and removed entirely by commit 258401a6 (mm: don't wait on congested zones in balance_pgdat()) as it was duplicating logic in shrink_inactive_list(). This is problematic. If kswapd encounters many pages under writeback and it continues to scan until it reaches the high watermark then it will quickly skip over the pages under writeback and reclaim clean young pages or push applications out to swap. The use of wait_iff_congested() is not suited to kswapd as it will only stall if the underlying BDI is really congested or a direct reclaimer was unable to write to the underlying BDI. kswapd bypasses the BDI congestion as it sets PF_SWAPWRITE but even if this was taken into account then it would cause direct reclaimers to stall on writeback which is not desirable. This patch sets a ZONE_WRITEBACK flag if direct reclaim or kswapd is encountering too many pages under writeback. If this flag is set and kswapd encounters a PageReclaim page under writeback then it'll assume that the LRU lists are being recycled too quickly before IO can complete and block waiting for some IO to complete. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Tested-by: Zlatko Calusic <zcalusic@bitsync.net> Cc: dormando <dormando@rydia.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2013-07-03 16:07:28 -07:00
..
backing-dev.c	writeback: expose the bdi_wq workqueue	2013-04-01 19:08:06 -07:00
balloon_compaction.c	mm: introduce a common interface for balloon pages mobility	2012-12-11 17:22:26 -08:00
bootmem.c	mm: Add alloc_bootmem_low_pages_nopanic()	2013-01-29 19:32:59 -08:00
bounce.c	Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block	2013-05-08 10:13:35 -07:00
cleancache.c	mm: cleancache: clean up cleancache_enabled	2013-04-30 17:04:01 -07:00
compaction.c	mm: add & use zone_end_pfn() and zone_spans_pfn()	2013-02-23 17:50:20 -08:00
debug-pagealloc.c	mm, x86: Remove debug_pagealloc_enabled	2011-12-06 09:24:07 +01:00
dmapool.c	dmapool: make DMAPOOL_DEBUG detect corruption of free marker	2012-12-11 17:22:24 -08:00
fadvise.c	teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long	2013-03-03 22:46:22 -05:00
failslab.c	switch debugfs to umode_t	2012-01-03 22:54:56 -05:00
filemap_xip.c	lift sb_start_write() out of ->write()	2013-04-09 14:12:56 -04:00
filemap.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2013-05-01 17:51:54 -07:00
fremap.c	Revert "mm: introduce VM_POPULATE flag to better deal with racy userspace programs"	2013-03-28 17:45:51 -07:00
frontswap.c	frontswap: fix incorrect zeroing and allocation size for frontswap_map	2013-06-12 16:29:46 -07:00
highmem.c	Some nice cleanups, and even a patch my wife did as a "live" demo for	2012-12-20 08:37:05 -08:00
huge_memory.c	mm: soft-dirty bits for user memory changes tracking	2013-07-03 16:07:26 -07:00
hugetlb_cgroup.c	mm/hugetlb: create hugetlb cgroup file in hugetlb_init	2012-12-18 15:02:15 -08:00
hugetlb.c	Main features:	2013-07-03 10:31:38 -07:00
hwpoison-inject.c	memcg: rename config variables	2012-07-31 18:42:43 -07:00
init-mm.c	atomic: use <linux/atomic.h>	2011-07-26 16:49:47 -07:00
internal.h	mm: accelerate munlock() treatment of THP pages	2013-02-27 19:10:09 -08:00
interval_tree.c	mm: add CONFIG_DEBUG_VM_RB build option	2012-10-09 16:22:42 +09:00
Kconfig	mm: soft-dirty bits for user memory changes tracking	2013-07-03 16:07:26 -07:00
Kconfig.debug	mm: more intensive memory corruption debugging	2012-01-10 16:30:42 -08:00
kmemcheck.c
kmemleak-test.c
kmemleak.c	hlist: drop the node parameter from iterators	2013-02-27 19:10:24 -08:00
ksm.c	ksm: fix m68k build: only NUMA needs pfn_to_nid	2013-03-08 15:05:34 -08:00
maccess.c	mm: Map most files to use export.h instead of module.h	2011-10-31 09:20:12 -04:00
madvise.c	mm: madvise: complete input validation before taking lock	2013-04-29 15:54:37 -07:00
Makefile	memcg: add memory.pressure_level events	2013-04-29 15:54:38 -07:00
memblock.c	memblock: fix missing comment of memblock_insert_region()	2013-04-29 15:54:38 -07:00
memcontrol.c	mm, memcg: don't take task_lock in task_in_mem_cgroup	2013-07-03 16:07:26 -07:00
memory_hotplug.c	mm/memory_hotplug.c: fix printk format warnings	2013-05-24 16:22:52 -07:00
memory-failure.c	HWPOISON: check dirty flag to match against clean page	2013-04-29 15:54:28 -07:00
memory.c	mm: use vma_pages() to replace (vm_end - vm_start) >> PAGE_SHIFT	2013-07-03 16:07:26 -07:00
mempolicy.c	mm/mempolicy.c: fix sp_node_init() argument ordering	2013-03-08 15:05:34 -08:00
mempool.c	mempool: add @gfp_mask to mempool_create_node()	2012-06-25 11:53:47 +02:00
migrate.c	mm: migration: add migrate_entry_wait_huge()	2013-06-12 16:29:46 -07:00
mincore.c	swap: make each swap partition have one address_space	2013-02-23 17:50:17 -08:00
mlock.c	Revert "mm: introduce VM_POPULATE flag to better deal with racy userspace programs"	2013-03-28 17:45:51 -07:00
mm_init.c	mm: init: report on last-nid information stored in page->flags	2013-02-23 17:50:18 -08:00
mmap.c	mm: use vma_pages() to replace (vm_end - vm_start) >> PAGE_SHIFT	2013-07-03 16:07:26 -07:00
mmu_context.c	mm: remove old aio use_mm() comment	2013-05-07 18:38:27 -07:00
mmu_notifier.c	mm: mmu_notifier: re-fix freed page still mapped in secondary MMU	2013-05-24 16:22:51 -07:00
mmzone.c	mm: rename page struct field helpers	2013-02-23 17:50:18 -08:00
mprotect.c	mm/mprotect.c: coding-style cleanups	2012-12-18 15:02:15 -08:00
mremap.c	mm: soft-dirty bits for user memory changes tracking	2013-07-03 16:07:26 -07:00
msync.c
nobootmem.c	mm, nobootmem: do memset() after memblock_reserve()	2013-04-29 15:54:39 -07:00
nommu.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal	2013-05-01 07:21:43 -07:00
oom_kill.c	memcg, oom: provide more precise dump info while memcg oom happening	2013-02-23 17:50:08 -08:00
page_alloc.c	mm/page_alloc: don't re-init pageset in zone_pcp_update()	2013-07-03 16:07:27 -07:00
page_cgroup.c	memcontrol: use N_MEMORY instead N_HIGH_MEMORY	2012-12-12 17:38:32 -08:00
page_io.c	mm: remove compressed copy from zram in-memory	2013-07-03 16:07:26 -07:00
page_isolation.c	mm: fix zone_watermark_ok_safe() accounting of isolated pages	2013-01-04 16:11:46 -08:00
page-writeback.c	mm: make snapshotting pages for stable writes a per-bio operation	2013-04-29 15:54:33 -07:00
pagewalk.c	mm/pagewalk.c: walk_page_range should avoid VM_PFNMAP areas	2013-05-24 16:22:53 -07:00
percpu-km.c
percpu-vm.c	mm: fix kernel-doc warnings	2012-06-20 14:39:36 -07:00
percpu.c	mm, percpu: Make sure percpu_alloc early parameter has an argument	2012-12-02 06:23:04 -08:00
pgtable-generic.c	mm: Only flush the TLB when clearing an accessible pte	2012-12-11 14:28:34 +00:00
process_vm_access.c	Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys	2013-03-12 11:05:45 -07:00
quicklist.c	mm: delete various needless include <linux/module.h>	2011-10-31 09:20:11 -04:00
readahead.c	mm: change invalidatepage prototype to accept length	2013-05-21 23:17:23 -04:00
rmap.c	rmap: recompute pgoff for unmapping huge page	2013-04-29 15:54:28 -07:00
shmem.c	vfs: export lseek_execute() to modules	2013-07-03 16:23:27 +04:00
slab_common.c	slab: prevent warnings when allocating with __GFP_NOWARN	2013-06-13 10:01:58 +03:00
slab.c	Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux	2013-05-07 08:42:20 -07:00
slab.h	slab: Common definition for kmem_cache_node	2013-02-01 12:32:09 +02:00
slob.c	mm: rename page struct field helpers	2013-02-23 17:50:18 -08:00
slub.c	Merge branch 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux	2013-05-07 08:42:20 -07:00
sparse-vmemmap.c	sparse-vmemmap: specify vmemmap population range in bytes	2013-04-29 15:54:35 -07:00
sparse.c	mm, hotplug: avoid compiling memory hotremove functions when disabled	2013-04-29 15:54:37 -07:00
swap_state.c	swap: avoid read_swap_cache_async() race to deadlock while waiting on discard I/O completion	2013-06-12 16:29:45 -07:00
swap.c	aio: don't include aio.h in sched.h	2013-05-07 20:16:25 -07:00
swapfile.c	frontswap: fix incorrect zeroing and allocation size for frontswap_map	2013-06-12 16:29:46 -07:00
truncate.c	mm: teach truncate_inode_pages_range() to handle non page aligned ranges	2013-05-27 23:32:35 -04:00
util.c	swap: make each swap partition have one address_space	2013-02-23 17:50:17 -08:00
vmalloc.c	mm/vmalloc.c: add vfree comment	2013-05-07 18:38:27 -07:00
vmpressure.c	memcg: add memory.pressure_level events	2013-04-29 15:54:38 -07:00
vmscan.c	mm: vmscan: block kswapd if it is encountering pages under writeback	2013-07-03 16:07:28 -07:00
vmstat.c	mm/vmstat: add note on safety of drain_zonestat	2013-04-29 15:54:38 -07:00