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| author | Bron Gondwana <brong@fastmail.fm> | 2008-02-05 07:29:20 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-05 18:44:18 +0100 |
| commit | 195cf453d2c3d789cbe80e3735755f860c2fb222 (patch) | |
| tree | fad48a8167744b6c091c8ca499bc78b859af8957 /Documentation/sysctl | |
| parent | Page allocator: get rid of the list of cold pages (diff) | |
| download | linux-195cf453d2c3d789cbe80e3735755f860c2fb222.tar.xz linux-195cf453d2c3d789cbe80e3735755f860c2fb222.zip | |
mm/page-writeback: highmem_is_dirtyable option
Add vm.highmem_is_dirtyable toggle
A 32 bit machine with HIGHMEM64 enabled running DCC has an MMAPed file of
approximately 2Gb size which contains a hash format that is written
randomly by the dbclean process. On 2.6.16 this process took a few
minutes. With lowmem only accounting of dirty ratios, this takes about 12
hours of 100% disk IO, all random writes.
Include a toggle in /proc/sys/vm/highmem_is_dirtyable which can be set to 1 to
add the highmem back to the total available memory count.
[akpm@linux-foundation.org: Fix the CONFIG_DETECT_SOFTLOCKUP=y build]
Signed-off-by: Bron Gondwana <brong@fastmail.fm>
Cc: Ethan Solomita <solo@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/sysctl')
| -rw-r--r-- | Documentation/sysctl/vm.txt | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 6f31f0a247d0..24eac1bc735d 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -22,6 +22,7 @@ Currently, these files are in /proc/sys/vm: - dirty_background_ratio - dirty_expire_centisecs - dirty_writeback_centisecs +- highmem_is_dirtyable (only if CONFIG_HIGHMEM set) - max_map_count - min_free_kbytes - laptop_mode @@ -40,9 +41,9 @@ Currently, these files are in /proc/sys/vm: ============================================================== dirty_ratio, dirty_background_ratio, dirty_expire_centisecs, -dirty_writeback_centisecs, vfs_cache_pressure, laptop_mode, -block_dump, swap_token_timeout, drop-caches, -hugepages_treat_as_movable: +dirty_writeback_centisecs, highmem_is_dirtyable, +vfs_cache_pressure, laptop_mode, block_dump, swap_token_timeout, +drop-caches, hugepages_treat_as_movable: See Documentation/filesystems/proc.txt |