The patch titled
Subject: mm/pagealloc: sysctl: change watermark_scale_factor max limit to 30%
has been added to the -mm tree. Its filename is
sysctl-change-watermark_scale_factor-max-limit-to-30%.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/sysctl-change-watermark_scale_factor-max-limit-to-30%25.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/sysctl-change-watermark_scale_factor-max-limit-to-30%25.patch
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------------------------------------------------------
From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: mm/pagealloc: sysctl: change watermark_scale_factor max limit to 30%
For embedded systems with low total memory, having to run applications
with relatively large memory requirements, 10% max limitation for
watermark_scale_factor poses an issue of triggering direct reclaim every
time such application is started. This results in slow application
startup times and bad end-user experience.
By increasing watermark_scale_factor max limit we allow vendors more
flexibility to choose the right level of kswapd aggressiveness for their
device and workload requirements.
Link: https://lkml.kernel.org/r/20211124193604.2758863-1-surenb@xxxxxxxxxx
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Lukas Middendorf <kernel@xxxxxxxxxxx>
Cc: Antti Palosaari <crope@xxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Iurii Zaikin <yzaikin@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Zhang Yi <yi.zhang@xxxxxxxxxx>
Cc: Fengfei Xi <xi.fengfei@xxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/sysctl/vm.rst | 2 +-
kernel/sysctl.c | 3 ++-
2 files changed, 3 insertions(+), 2 deletions(-)
--- a/Documentation/admin-guide/sysctl/vm.rst~sysctl-change-watermark_scale_factor-max-limit-to-30%
+++ a/Documentation/admin-guide/sysctl/vm.rst
@@ -948,7 +948,7 @@ how much memory needs to be free before
The unit is in fractions of 10,000. The default value of 10 means the
distances between watermarks are 0.1% of the available memory in the
-node/system. The maximum value is 1000, or 10% of memory.
+node/system. The maximum value is 3000, or 30% of memory.
A high rate of threads entering direct reclaim (allocstall) or kswapd
going to sleep prematurely (kswapd_low_wmark_hit_quickly) can indicate
--- a/kernel/sysctl.c~sysctl-change-watermark_scale_factor-max-limit-to-30%
+++ a/kernel/sysctl.c
@@ -122,6 +122,7 @@ static unsigned long long_max = LONG_MAX
static int one_hundred = 100;
static int two_hundred = 200;
static int one_thousand = 1000;
+static int three_thousand = 3000;
#ifdef CONFIG_PRINTK
static int ten_thousand = 10000;
#endif
@@ -2959,7 +2960,7 @@ static struct ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = watermark_scale_factor_sysctl_handler,
.extra1 = SYSCTL_ONE,
- .extra2 = &one_thousand,
+ .extra2 = &three_thousand,
},
{
.procname = "percpu_pagelist_high_fraction",
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
mm-add-a-field-to-store-names-for-private-anonymous-memory-fix.patch
mm-add-anonymous-vma-name-refcounting.patch
sysctl-change-watermark_scale_factor-max-limit-to-30%.patch
