2015-02-26 21:34:55

by Ebru Akagunduz

[permalink] [raw]
Subject: [PATCH] doc: add information about max_ptes_none

max_ptes_none specifies how many extra small pages (that are
not already mapped) can be allocated when collapsing a group
of small pages into one large page.

/sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_none

A higher value leads to use additional memory for programs.
A lower value leads to gain less thp performance. Value of
max_ptes_none can waste cpu time very little, you can
ignore it.

Signed-off-by: Ebru Akagunduz <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
---
Documentation/vm/transhuge.txt | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/Documentation/vm/transhuge.txt b/Documentation/vm/transhuge.txt
index 6b31cfb..8143b9e 100644
--- a/Documentation/vm/transhuge.txt
+++ b/Documentation/vm/transhuge.txt
@@ -159,6 +159,17 @@ for each pass:

/sys/kernel/mm/transparent_hugepage/khugepaged/full_scans

+max_ptes_none specifies how many extra small pages (that are
+not already mapped) can be allocated when collapsing a group
+of small pages into one large page.
+
+/sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_none
+
+A higher value leads to use additional memory for programs.
+A lower value leads to gain less thp performance. Value of
+max_ptes_none can waste cpu time very little, you can
+ignore it.
+
== Boot parameter ==

You can change the sysfs boot time defaults of Transparent Hugepage
--
1.9.1


2015-02-27 22:14:47

by Jonathan Corbet

[permalink] [raw]
Subject: Re: [PATCH] doc: add information about max_ptes_none

On Thu, 26 Feb 2015 23:34:36 +0200
Ebru Akagunduz <[email protected]> wrote:

> max_ptes_none specifies how many extra small pages (that are
> not already mapped) can be allocated when collapsing a group
> of small pages into one large page.
>
> /sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_none
>
> A higher value leads to use additional memory for programs.
> A lower value leads to gain less thp performance. Value of
> max_ptes_none can waste cpu time very little, you can
> ignore it.

Applied to the docs tree, thanks.

jon