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authorPaul Jackson <pj@sgi.com>2005-09-06 18:18:13 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2005-09-07 19:57:40 -0400
commitef08e3b4981aebf2ba9bd7025ef7210e8eec07ce (patch)
tree3b5386e011c87dde384115c8eb0d6961c2536025 /kernel
parent9bf2229f8817677127a60c177aefce1badd22d7b (diff)
[PATCH] cpusets: confine oom_killer to mem_exclusive cpuset
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpuset.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 214806deca99..40c6d801dd66 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1688,6 +1688,39 @@ done:
1688 return allowed; 1688 return allowed;
1689} 1689}
1690 1690
1691/**
1692 * cpuset_excl_nodes_overlap - Do we overlap @p's mem_exclusive ancestors?
1693 * @p: pointer to task_struct of some other task.
1694 *
1695 * Description: Return true if the nearest mem_exclusive ancestor
1696 * cpusets of tasks @p and current overlap. Used by oom killer to
1697 * determine if task @p's memory usage might impact the memory
1698 * available to the current task.
1699 *
1700 * Acquires cpuset_sem - not suitable for calling from a fast path.
1701 **/
1702
1703int cpuset_excl_nodes_overlap(const struct task_struct *p)
1704{
1705 const struct cpuset *cs1, *cs2; /* my and p's cpuset ancestors */
1706 int overlap = 0; /* do cpusets overlap? */
1707
1708 down(&cpuset_sem);
1709 cs1 = current->cpuset;
1710 if (!cs1)
1711 goto done; /* current task exiting */
1712 cs2 = p->cpuset;
1713 if (!cs2)
1714 goto done; /* task p is exiting */
1715 cs1 = nearest_exclusive_ancestor(cs1);
1716 cs2 = nearest_exclusive_ancestor(cs2);
1717 overlap = nodes_intersects(cs1->mems_allowed, cs2->mems_allowed);
1718done:
1719 up(&cpuset_sem);
1720
1721 return overlap;
1722}
1723
1691/* 1724/*
1692 * proc_cpuset_show() 1725 * proc_cpuset_show()
1693 * - Print tasks cpuset path into seq_file. 1726 * - Print tasks cpuset path into seq_file.