path: root/include
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authorAndrew Shewmaker <agshew@gmail.com>2013-04-29 15:08:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-29 15:54:36 -0700
commit4eeab4f5580d11bffedc697684b91b0bca0d5009 (patch)
tree4e9a0c010d34e786df52225039a17aa38e9adf17 /include
parentc9b1d0981fcce3d9976d7b7a56e4e0503bc610dd (diff)
mm: replace hardcoded 3% with admin_reserve_pages knob
Add an admin_reserve_kbytes knob to allow admins to change the hardcoded memory reserve to something other than 3%, which may be multiple gigabytes on large memory systems. Only about 8MB is necessary to enable recovery in the default mode, and only a few hundred MB are required even when overcommit is disabled. This affects OVERCOMMIT_GUESS and OVERCOMMIT_NEVER. admin_reserve_kbytes is initialized to min(3% free pages, 8MB) I arrived at 8MB by summing the RSS of sshd or login, bash, and top. Please see first patch in this series for full background, motivation, testing, and full changelog. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: make init_admin_reserve() static] Signed-off-by: Andrew Shewmaker <agshew@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 43cfaabbde4..c05d7cfbb6b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -45,6 +45,7 @@ extern int sysctl_legacy_va_layout;
#include <asm/processor.h>
extern unsigned long sysctl_user_reserve_kbytes;
+extern unsigned long sysctl_admin_reserve_kbytes;
#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))