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authorBron Gondwana <brong@fastmail.fm>2008-02-05 09:29:20 +0300
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 20:44:18 +0300
commit195cf453d2c3d789cbe80e3735755f860c2fb222 (patch)
treefad48a8167744b6c091c8ca499bc78b859af8957 /Documentation/sysctl
parent3dfa5721f12c3d5a441448086bee156887daa961 (diff)
downloadlinux-195cf453d2c3d789cbe80e3735755f860c2fb222.tar.xz
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.txt7
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