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 --- Documentation/sysctl/vm.txt | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'Documentation/sysctl') 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 -- cgit v1.2.3