From 195cf453d2c3d789cbe80e3735755f860c2fb222 Mon Sep 17 00:00:00 2001 From: Bron Gondwana Date: Mon, 4 Feb 2008 22:29:20 -0800 Subject: 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 Cc: Ethan Solomita Cc: Peter Zijlstra Cc: WU Fengguang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/writeback.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index c6148bb..b2cd826 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; -- cgit v1.1