kernel_optimize_test/mm
Johannes Weiner ab8fabd46f mm: exclude reserved pages from dirtyable memory
Per-zone dirty limits try to distribute page cache pages allocated for
writing across zones in proportion to the individual zone sizes, to reduce
the likelihood of reclaim having to write back individual pages from the
LRU lists in order to make progress.

This patch:

The amount of dirtyable pages should not include the full number of free
pages: there is a number of reserved pages that the page allocator and
kswapd always try to keep free.

The closer (reclaimable pages - dirty pages) is to the number of reserved
pages, the more likely it becomes for reclaim to run into dirty pages:

       +----------+ ---
       |   anon   |  |
       +----------+  |
       |          |  |
       |          |  -- dirty limit new    -- flusher new
       |   file   |  |                     |
       |          |  |                     |
       |          |  -- dirty limit old    -- flusher old
       |          |                        |
       +----------+                       --- reclaim
       | reserved |
       +----------+
       |  kernel  |
       +----------+

This patch introduces a per-zone dirty reserve that takes both the lowmem
reserve as well as the high watermark of the zone into account, and a
global sum of those per-zone values that is subtracted from the global
amount of dirtyable pages.  The lowmem reserve is unavailable to page
cache allocations and kswapd tries to keep the high watermark free.  We
don't want to end up in a situation where reclaim has to clean pages in
order to balance zones.

Not treating reserved pages as dirtyable on a global level is only a
conceptual fix.  In reality, dirty pages are not distributed equally
across zones and reclaim runs into dirty pages on a regular basis.

But it is important to get this right before tackling the problem on a
per-zone level, where the distance between reclaim and the dirty pages is
mostly much smaller in absolute numbers.

[akpm@linux-foundation.org: fix highmem build]
Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-10 16:30:43 -08:00
..
backing-dev.c freezer: implement and use kthread_freezable_should_stop() 2011-11-21 12:32:23 -08:00
bootmem.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
bounce.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
cleancache.c
compaction.c convert 'memory' sysdev_class to a regular subsystem 2011-12-21 14:48:43 -08:00
debug-pagealloc.c debug-pagealloc: add support for highmem pages 2011-10-31 17:30:48 -07:00
dmapool.c mm: fix implicit stat.h usage in dmapool.c 2011-10-31 09:20:12 -04:00
fadvise.c fadvise: only initiate writeback for specified range with FADV_DONTNEED 2012-01-10 16:30:43 -08:00
failslab.c switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
filemap_xip.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
filemap.c should_remove_suid(): inode->i_mode is umode_t 2012-01-03 22:55:14 -05:00
fremap.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
highmem.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
huge_memory.c thp: reduce khugepaged freezing latency 2011-12-09 07:50:28 -08:00
hugetlb.c mm/hugetlb.c: fix virtual address handling in hugetlb fault 2012-01-10 16:30:42 -08:00
hwpoison-inject.c
init-mm.c atomic: use <linux/atomic.h> 2011-07-26 16:49:47 -07:00
internal.h mm: thp: tail page refcounting fix 2011-11-02 16:06:57 -07:00
Kconfig Merge branch 'master' into x86/memblock 2011-11-28 09:46:22 -08:00
Kconfig.debug mm: more intensive memory corruption debugging 2012-01-10 16:30:42 -08:00
kmemcheck.c
kmemleak-test.c
kmemleak.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
ksm.c oom: fix race while temporarily setting current's oom_score_adj 2011-10-31 17:30:45 -07:00
maccess.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
madvise.c
Makefile Cross Memory Attach 2011-10-31 17:30:44 -07:00
memblock.c memblock: Reimplement memblock allocation using reverse free area iterator 2011-12-08 10:22:09 -08:00
memcontrol.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-01-09 14:46:52 -08:00
memory_hotplug.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
memory-failure.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
memory.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
mempolicy.c mm/mempolicy.c: refix mbind_range() vma issue 2011-12-29 16:31:57 -08:00
mempool.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
migrate.c mm: migrate: one less atomic operation 2012-01-10 16:30:41 -08:00
mincore.c mm: clarify the radix_tree exceptional cases 2011-08-03 14:25:24 -10:00
mlock.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
mm_init.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
mmap.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
mmu_context.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
mmu_notifier.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
mmzone.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
mprotect.c
mremap.c thp: mremap support and TLB optimization 2011-10-31 17:30:48 -07:00
msync.c
nobootmem.c Merge branch 'master' into x86/memblock 2011-11-28 09:46:22 -08:00
nommu.c xen: map foreign pages for shared rings by updating the PTEs directly 2011-11-16 12:13:08 -05:00
oom_kill.c Merge branch 'master' into pm-sleep 2011-12-21 21:59:45 +01:00
page_alloc.c mm: exclude reserved pages from dirtyable memory 2012-01-10 16:30:43 -08:00
page_cgroup.c mm/page_cgroup.c: quiet sparse noise 2011-11-02 16:07:00 -07:00
page_io.c
page_isolation.c
page-writeback.c mm: exclude reserved pages from dirtyable memory 2012-01-10 16:30:43 -08:00
pagewalk.c
percpu-km.c
percpu-vm.c percpu: fix chunk range calculation 2011-11-22 08:09:46 -08:00
percpu.c percpu: fix per_cpu_ptr_to_phys() handling of non-page-aligned addresses 2011-12-15 11:41:40 -08:00
pgtable-generic.c
prio_tree.c
process_vm_access.c Cross Memory Attach 2011-10-31 17:30:44 -07:00
quicklist.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
readahead.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
rmap.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
shmem.c vfs: switch ->show_options() to struct dentry * 2012-01-06 23:19:54 -05:00
slab.c tracing/mm: Move include of trace/events/kmem.h out of header into slab.c 2012-01-09 14:19:33 -08:00
slob.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
slub.c slub: min order when debug_guardpage_minorder > 0 2012-01-10 16:30:43 -08:00
sparse-vmemmap.c mm: delete various needless include <linux/module.h> 2011-10-31 09:20:11 -04:00
sparse.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
swap_state.c fs: move code out of buffer.c 2012-01-03 22:54:07 -05:00
swap.c mm: add free_hot_cold_page_list() helper 2012-01-10 16:30:41 -08:00
swapfile.c mm: avoid livelock on !__GFP_FS allocations 2012-01-10 16:30:42 -08:00
thrash.c mm/thrash.c: quiet sparse noise 2011-10-31 17:30:50 -07:00
truncate.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
util.c mm: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
vmalloc.c Merge branch 'devel-stable' into for-linus 2012-01-05 13:24:33 +00:00
vmscan.c vmscan: add task name to warn_scan_unevictable() messages 2012-01-10 16:30:43 -08:00
vmstat.c mm/vmstat.c: cache align vm_stat 2011-10-31 17:30:51 -07:00