From 80f73b4b71f767f7fcd85f68be18af7795904484 Mon Sep 17 00:00:00 2001 From: Ebru Akagunduz Date: Thu, 5 Nov 2015 18:47:32 -0800 Subject: [PATCH] Documentation/vm/transhuge.txt: add information about max_ptes_swap max_ptes_swap specifies how many pages can be brought in from swap when collapsing a group of pages into a transparent huge page. /sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_swap A higher value can cause excessive swap IO and waste memory. A lower value can prevent THPs from being collapsed, resulting fewer pages being collapsed into THPs, and lower memory access performance. Signed-off-by: Ebru Akagunduz Acked-by: Rik van Riel Acked-by: David Rientjes Cc: Oleg Nesterov Cc: Kirill A. Shutemov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/vm/transhuge.txt | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/vm/transhuge.txt b/Documentation/vm/transhuge.txt index 8143b9e..8a28268 100644 --- a/Documentation/vm/transhuge.txt +++ b/Documentation/vm/transhuge.txt @@ -170,6 +170,16 @@ A lower value leads to gain less thp performance. Value of max_ptes_none can waste cpu time very little, you can ignore it. +max_ptes_swap specifies how many pages can be brought in from +swap when collapsing a group of pages into a transparent huge page. + +/sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_swap + +A higher value can cause excessive swap IO and waste +memory. A lower value can prevent THPs from being +collapsed, resulting fewer pages being collapsed into +THPs, and lower memory access performance. + == Boot parameter == You can change the sysfs boot time defaults of Transparent Hugepage -- 2.7.4