Richard Kennedy d7831a0bdf mm: prevent balance_dirty_pages() from doing too much work ... balance_dirty_pages can overreact and move all of the dirty pages to writeback unnecessarily. balance_dirty_pages makes its decision to throttle based on the number of dirty plus writeback pages that are over the calculated limit,so it will continue to move pages even when there are plenty of pages in writeback and less than the threshold still dirty. This allows it to overshoot its limits and move all the dirty pages to writeback while waiting for the drives to catch up and empty the writeback list. A simple fio test easily demonstrates this problem. fio --name=f1 --directory=/disk1 --size=2G -rw=write --name=f2 --directory=/disk2 --size=1G --rw=write --startdelay=10 This is the simplest fix I could find, but I'm not entirely sure that it alone will be enough for all cases. But it certainly is an improvement on my desktop machine writing to 2 disks. Do we need something more for machines with large arrays where bdi_threshold * number_of_drives is greater than the dirty_ratio ? Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2009-06-30 18:56:01 -07:00
..
allocpercpu.c	percpu: __percpu_depopulate_mask can take a const mask	2009-04-06 13:44:15 -07:00
backing-dev.c	block: change the request allocation/congestion logic to be sync/async based	2009-04-06 08:04:53 -07:00
bootmem.c	bootmem.c: avoid c90 declaration warning	2009-06-19 16:46:04 -07:00
bounce.c	block: remove some includings of blktrace_api.h	2009-06-16 11:19:36 +02:00
debug-pagealloc.c	generic debug pagealloc	2009-04-01 08:59:13 -07:00
dmapool.c	dmapools: protect page_list walk in show_pools()	2009-06-30 18:56:00 -07:00
fadvise.c	readahead: move max_sane_readahead() calls into force_page_cache_readahead()	2009-06-16 19:47:28 -07:00
failslab.c	kmemtrace, mm: fix slab.h dependency problem in mm/failslab.c	2009-04-03 12:23:01 +02:00
filemap.c	page allocator: do not check NUMA node ID when the caller knows the node is valid	2009-06-16 19:47:32 -07:00
filemap_xip.c	mm: do_xip_mapping_read: fix length calculation	2009-04-02 19:04:49 -07:00
fremap.c	Do not account for the address space used by hugetlbfs using VM_ACCOUNT	2009-02-10 10:48:42 -08:00
highmem.c	block: remove some includings of blktrace_api.h	2009-06-16 11:19:36 +02:00
hugetlb.c	hugetlb: fault flags instead of write_access	2009-06-23 11:23:33 -07:00
init-mm.c	mm: consolidate init_mm definition	2009-06-16 19:47:28 -07:00
internal.h	vmscan: do not unconditionally treat zones that fail zone_reclaim() as full	2009-06-16 19:47:45 -07:00
Kconfig	Merge branch 'akpm'	2009-06-16 19:50:13 -07:00
Kconfig.debug	kmemcheck: enable in the x86 Kconfig	2009-06-15 15:49:15 +02:00
kmemcheck.c	kmemcheck: add hooks for the page allocator	2009-06-15 15:48:33 +02:00
kmemleak-test.c	kmemleak: Simple testing module for kmemleak	2009-06-11 17:04:19 +01:00
kmemleak.c	kmemleak: use pr_fmt	2009-06-23 14:40:26 +01:00
maccess.c	[S390] maccess: add weak attribute to probe_kernel_write	2009-06-12 10:27:37 +02:00
madvise.c	mm: madvise(): correct return code	2009-06-16 19:47:40 -07:00
Makefile	Merge branch 'akpm'	2009-06-16 19:50:13 -07:00
memcontrol.c	memcg: fix lru rotation in isolate_pages	2009-06-18 13:03:48 -07:00
memory.c	clarify get_user_pages() prototype	2009-06-25 11:22:13 -07:00
memory_hotplug.c	page-allocator: reset wmark_min and inactive ratio of zone when hotplug happens	2009-06-16 19:47:42 -07:00
mempolicy.c	page allocator: do not check NUMA node ID when the caller knows the node is valid	2009-06-16 19:47:32 -07:00
mempool.c
migrate.c	migration: only migrate_prep() once per move_pages()	2009-06-16 19:47:41 -07:00
mincore.c	[CVE-2009-0029] System call wrappers part 14	2009-01-14 14:15:24 +01:00
mlock.c	mm: remove CONFIG_UNEVICTABLE_LRU config option	2009-06-16 19:47:42 -07:00
mm_init.c
mmap.c	Merge branch 'perfcounters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-06-11 14:01:07 -07:00
mmu_notifier.c
mmzone.c	[ARM] Double check memmap is actually valid with a memmap has unexpected holes V2	2009-05-18 11:22:24 +01:00
mprotect.c	perf_counter: Add mmap event hooks to mprotect()	2009-06-08 23:10:43 +02:00
mremap.c	[CVE-2009-0029] System call wrappers part 13	2009-01-14 14:15:23 +01:00
msync.c	[CVE-2009-0029] System call wrappers part 13	2009-01-14 14:15:23 +01:00
nommu.c	clarify get_user_pages() prototype	2009-06-25 11:22:13 -07:00
oom_kill.c	oom: only oom kill exiting tasks with attached memory	2009-06-16 19:47:45 -07:00
page-writeback.c	mm: prevent balance_dirty_pages() from doing too much work	2009-06-30 18:56:01 -07:00
page_alloc.c	Don't warn about order-1 allocations with __GFP_NOFAIL	2009-06-24 12:16:49 -07:00
page_cgroup.c	memcg: remove some redundant checks	2009-06-18 13:03:47 -07:00
page_io.c	mm: remove file argument from swap_readpage()	2009-06-16 19:47:44 -07:00
page_isolation.c
pagewalk.c
pdflush.c	Revert "mm: add /proc controls for pdflush threads"	2009-05-15 11:32:24 +02:00
percpu.c	x86: implement percpu_alloc kernel parameter	2009-06-22 11:56:24 +09:00
prio_tree.c
quicklist.c	cpumask: replace node_to_cpumask with cpumask_of_node.	2009-03-13 14:49:46 +10:30
readahead.c	readahead: introduce context readahead algorithm	2009-06-16 19:47:30 -07:00
rmap.c	memcg: add file-based RSS accounting	2009-06-18 13:03:47 -07:00
shmem.c	Get "no acls for this inode" right, fix shmem breakage	2009-06-24 16:58:48 -04:00
shmem_acl.c	switch shmem to inode->i_acl	2009-06-24 08:17:06 -04:00
slab.c	mm: Extend gfp masking to the page allocator	2009-06-18 13:12:57 -07:00
slob.c	Merge branches 'slab/documentation', 'slab/fixes', 'slob/cleanups' and 'slub/fixes' into for-linus	2009-06-17 08:30:15 +03:00
slub.c	SLUB: Don't pass __GFP_FAIL for the initial allocation	2009-06-24 12:20:14 -07:00
sparse-vmemmap.c
sparse.c	mm: mminit_validate_memmodel_limits(): remove redundant test	2009-04-01 08:59:11 -07:00
swap.c	mm: fix Committed_AS underflow on large NR_CPUS environment	2009-05-02 15:36:10 -07:00
swap_state.c	mm: remove file argument from swap_readpage()	2009-06-16 19:47:44 -07:00
swapfile.c	memcg: fix swap accounting	2009-06-18 13:03:47 -07:00
thrash.c	mm: pass mm to grab_swap_token	2009-06-23 12:50:05 -07:00
truncate.c	mm: remove __invalidate_mapping_pages variant	2009-06-16 19:47:43 -07:00
util.c	Merge branches 'slab/documentation', 'slab/fixes', 'slob/cleanups' and 'slub/fixes' into for-linus	2009-06-17 08:30:15 +03:00
vmalloc.c	Merge branch 'for-linus' of git://linux-arm.org/linux-2.6	2009-06-11 14:15:57 -07:00
vmscan.c	mm: fix incorrect page removal from LRU	2009-06-23 10:17:28 -07:00
vmstat.c	vmscan: count the number of times zone_reclaim() scans and fails	2009-06-16 19:47:46 -07:00