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authorHuang Ying <ying.huang@intel.com>2017-09-07 02:24:40 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-07 03:27:29 +0300
commitd9bfcfdc41e8e5d80f7591f95a09ccce7cb8ad05 (patch)
treec0844737c2d37eab327d6dfb0c446ef111b92d4f /Documentation/ABI
parentec560175c0b6fce86994bdf036754d48122c5c87 (diff)
downloadlinux-d9bfcfdc41e8e5d80f7591f95a09ccce7cb8ad05.tar.xz
mm, swap: add sysfs interface for VMA based swap readahead
The sysfs interface to control the VMA based swap readahead is added as follow, /sys/kernel/mm/swap/vma_ra_enabled Enable the VMA based swap readahead algorithm, or use the original global swap readahead algorithm. /sys/kernel/mm/swap/vma_ra_max_order Set the max order of the readahead window size for the VMA based swap readahead algorithm. The corresponding ABI documentation is added too. Link: http://lkml.kernel.org/r/20170807054038.1843-5-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/testing/sysfs-kernel-mm-swap26
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+What: /sys/kernel/mm/swap/
+Date: August 2017
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Interface for swapping
+
+What: /sys/kernel/mm/swap/vma_ra_enabled
+Date: August 2017
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: Enable/disable VMA based swap readahead.
+
+ If set to true, the VMA based swap readahead algorithm
+ will be used for swappable anonymous pages mapped in a
+ VMA, and the global swap readahead algorithm will be
+ still used for tmpfs etc. other users. If set to
+ false, the global swap readahead algorithm will be
+ used for all swappable pages.
+
+What: /sys/kernel/mm/swap/vma_ra_max_order
+Date: August 2017
+Contact: Linux memory management mailing list <linux-mm@kvack.org>
+Description: The max readahead size in order for VMA based swap readahead
+
+ VMA based swap readahead algorithm will readahead at
+ most 1 << max_order pages for each readahead. The
+ real readahead size for each readahead will be scaled
+ according to the estimation algorithm.