61b63972 - mm, swap: use page-cluster as max window of VMA based swap readahead

Fri, 13 Oct 2017 22:58:29 +0000

mm, swap: use page-cluster as max window of VMA based swap readaheadWhen the VMA based swap readahead was introduced, a new knob /sys/kernel/mm/swap/vma_ra_max_orderwas added as the max window of VMA swap readahead. This is to make itpossible to use different max window for VMA based readahead andoriginal physical readahead. But Minchan Kim pointed out that this willcause a regression because setting page-cluster sysctl to zero cannotdisable swap readahead with the change.To fix the regression, the page-cluster sysctl is used as the max windowof both the VMA based swap readahead and original physical swapreadahead. If more fine grained control is needed in the future, moreknobs can be added as the subordinate knobs of the page-cluster sysctl.The vma_ra_max_order knob is deleted. Because the knob was introducedin v4.14-rc1, and this patch is targeting being merged before v4.14releasing, there should be no existing users of this newly added ABI.Link: http://lkml.kernel.org/r/20171011070847.16003-1-ying.huang@intel.comFixes: ec560175c0b6fce ("mm, swap: VMA based swap readahead")Signed-off-by: "Huang, Ying" Reported-by: Minchan Kim Acked-by: Minchan Kim Acked-by: Michal Hocko Cc: Johannes Weiner 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 List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-mm-swap

d9bfcfdc - mm, swap: add sysfs interface for VMA based swap readahead

Wed, 06 Sep 2017 23:24:40 +0000

mm, swap: add sysfs interface for VMA based swap readaheadThe sysfs interface to control the VMA based swap readahead is added asfollow,/sys/kernel/mm/swap/vma_ra_enabledEnable the VMA based swap readahead algorithm, or use the originalglobal swap readahead algorithm./sys/kernel/mm/swap/vma_ra_max_orderSet the max order of the readahead window size for the VMA based swapreadahead algorithm.The corresponding ABI documentation is added too.Link: http://lkml.kernel.org/r/20170807054038.1843-5-ying.huang@intel.comSigned-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 List of files: /linux-6.15/Documentation/ABI/testing/sysfs-kernel-mm-swap

Changes in sysfs-kernel-mm-swap

61b63972 - mm, swap: use page-cluster as max window of VMA based swap readahead

d9bfcfdc - mm, swap: add sysfs interface for VMA based swap readahead