lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[PATCH] cpusets: confine oom_killer to mem_exclusive cpuset

Browse Source 
Now the real motivation for this cpuset mem_exclusive patch series seems
trivial.

This patch keeps a task in or under one mem_exclusive cpuset from provoking an
oom kill of a task under a non-overlapping mem_exclusive cpuset.  Since only
interrupt and GFP_ATOMIC allocations are allowed to escape mem_exclusive
containment, there is little to gain from oom killing a task under a
non-overlapping mem_exclusive cpuset, as almost all kernel and user memory
allocation must come from disjoint memory nodes.

This patch enables configuring a system so that a runaway job under one
mem_exclusive cpuset cannot cause the killing of a job in another such cpuset
that might be using very high compute and memory resources for a prolonged
time.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Paul Jackson
2005-09-06 15:18:13 -07:00
committed by Linus Torvalds
parent 9bf2229f88
commit ef08e3b498
3 changed files with 44 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
kernel/cpuset.c
View File

@ -1688,6 +1688,39 @@ done:
return allowed;
}
/**
* cpuset_excl_nodes_overlap - Do we overlap @p's mem_exclusive ancestors?
* @p: pointer to task_struct of some other task.
*
* Description: Return true if the nearest mem_exclusive ancestor
* cpusets of tasks @p and current overlap. Used by oom killer to
* determine if task @p's memory usage might impact the memory
* available to the current task.
*
* Acquires cpuset_sem - not suitable for calling from a fast path.
**/
int cpuset_excl_nodes_overlap(const struct task_struct *p)
{
const struct cpuset *cs1, *cs2; /* my and p's cpuset ancestors */
int overlap = 0; /* do cpusets overlap? */
down(&cpuset_sem);
cs1 = current->cpuset;
if (!cs1)
goto done; /* current task exiting */
cs2 = p->cpuset;
if (!cs2)
goto done; /* task p is exiting */
cs1 = nearest_exclusive_ancestor(cs1);
cs2 = nearest_exclusive_ancestor(cs2);
overlap = nodes_intersects(cs1->mems_allowed, cs2->mems_allowed);
done:
up(&cpuset_sem);
return overlap;
}
/*
* proc_cpuset_show()
* - Print tasks cpuset path into seq_file.