From d9bfcfdc41e8e5d80f7591f95a09ccce7cb8ad05 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 6 Sep 2017 16:24:40 -0700 Subject: 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" Cc: Johannes Weiner Cc: Minchan Kim Cc: Rik van Riel Cc: Shaohua Li Cc: Hugh Dickins Cc: Fengguang Wu Cc: Tim Chen Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/ABI/testing/sysfs-kernel-mm-swap | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-kernel-mm-swap (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-kernel-mm-swap b/Documentation/ABI/testing/sysfs-kernel-mm-swap new file mode 100644 index 000000000000..587db52084c7 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-kernel-mm-swap @@ -0,0 +1,26 @@ +What: /sys/kernel/mm/swap/ +Date: August 2017 +Contact: Linux memory management mailing list +Description: Interface for swapping + +What: /sys/kernel/mm/swap/vma_ra_enabled +Date: August 2017 +Contact: Linux memory management mailing list +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 +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. -- cgit v1.2.3