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 <ebru.akagunduz@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ebru Akagunduz 2015-11-05 18:47:32 -08:00 committed by Linus Torvalds
parent 3608de0787
commit 80f73b4b71
1 changed files with 10 additions and 0 deletions

View File

@ -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