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authorBron Gondwana <brong@fastmail.fm>2008-02-04 22:29:20 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-05 09:44:18 -0800
commit195cf453d2c3d789cbe80e3735755f860c2fb222 (patch)
treefad48a8167744b6c091c8ca499bc78b859af8957 /include
parent3dfa5721f12c3d5a441448086bee156887daa961 (diff)
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 'include')
-rw-r--r--include/linux/writeback.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index c6148bbf125..b2cd826a8c9 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -100,6 +100,7 @@ extern int dirty_background_ratio;
extern int vm_dirty_ratio;
extern int dirty_writeback_interval;
extern int dirty_expire_interval;
+extern int vm_highmem_is_dirtyable;
extern int block_dump;
extern int laptop_mode;