Messages in this thread Patch in this message | | | Date | Wed, 28 Oct 2009 17:58:46 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | [PATCH] oom_kill: use rss value instead of vm size for badness |
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I may add more tweaks based on this. But simple start point as this patch will be good. This patch is based on mmotm + Kosaki's http://marc.info/?l=linux-kernel&m=125669809305167&w=2
Test results on various environment are appreciated.
Regards. -Kame == From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
It's reported that OOM-Killer kills Gnone/KDE at first... And yes, we can reproduce it easily.
Now, oom-killer uses mm->total_vm as its base value. But in recent applications, there are a big gap between VM size and RSS size. Because - Applications attaches much dynamic libraries. (Gnome, KDE, etc...) - Applications may alloc big VM area but use small part of them. (Java, and multi-threaded applications has this tendency because of default-size of stack.)
I think using mm->total_vm as score for oom-kill is not good. By the same reason, overcommit memory can't work as expected. (In other words, if we depends on total_vm, using overcommit more positive is a good choice.)
This patch uses mm->anon_rss/file_rss as base value for calculating badness.
Following is changes to OOM score(badness) on an environment with 1.6G memory plus memory-eater(500M & 1G).
Top 10 of badness score. (The highest one is the first candidate to be killed) Before badness program 91228 gnome-settings- 94210 clock-applet 103202 mixer_applet2 106563 tomboy 112947 gnome-terminal 128944 mmap <----------- 500M malloc 129332 nautilus 215476 bash <----------- parent of 2 mallocs. 256944 mmap <----------- 1G malloc 423586 gnome-session
After badness 1911 mixer_applet2 1955 clock-applet 1986 xinit 1989 gnome-session 2293 nautilus 2955 gnome-terminal 4113 tomboy 104163 mmap <----------- 500M malloc. 168577 bash <----------- parent of 2 mallocs 232375 mmap <----------- 1G malloc
seems good for me.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> --- mm/oom_kill.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
Index: mm-test-kernel/mm/oom_kill.c =================================================================== --- mm-test-kernel.orig/mm/oom_kill.c +++ mm-test-kernel/mm/oom_kill.c @@ -93,7 +93,7 @@ unsigned long badness(struct task_struct /* * The memory size of the process is the basis for the badness. */ - points = mm->total_vm; + points = get_mm_counter(mm, anon_rss) + get_mm_counter(mm, file_rss); /* * After this unlock we can no longer dereference local variable `mm' @@ -116,8 +116,12 @@ unsigned long badness(struct task_struct */ list_for_each_entry(child, &p->children, sibling) { task_lock(child); - if (child->mm != mm && child->mm) - points += child->mm->total_vm/2 + 1; + if (child->mm != mm && child->mm) { + unsigned long cpoints; + cpoints = get_mm_counter(child->mm, anon_rss); + + get_mm_counter(child->mm, file_rss); + points += cpoints/2 + 1; + } task_unlock(child); }
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