Messages in this thread | | | Date | Mon, 9 Sep 2013 02:00:26 -0700 (PDT) | From | David Rientjes <> | Subject | Re: [patch] mm, memcg: store memcg name for oom kill log consistency |
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On Thu, 5 Sep 2013, Michal Hocko wrote:
> From 4cee36f56100f5689fe1ae22f468016ce5a0cbae Mon Sep 17 00:00:00 2001 > From: Michal Hocko <mhocko@suse.cz> > Date: Thu, 5 Sep 2013 15:39:20 +0200 > Subject: [PATCH] memcg, oom: lock mem_cgroup_print_oom_info > > mem_cgroup_print_oom_info uses a static buffer (memcg_name) to store the > name of the cgroup. This is not safe as pointed out by David Rientjes > because although memcg oom is locked for its hierarchy nothing prevents > another parallel hierarchy to trigger oom as well and overwrite the > already in-use buffer. > > This patch introduces oom_info_lock hidden inside mem_cgroup_print_oom_info > which is held throughout the function. It make access to memcg_name safe > and as a bonus it also prevents parallel memcg ooms to interleave their > statistics which would make the printed data hard to analyze otherwise. > > Using the spinlock is OK here because this path is not hot and > meaningful data is much more important. > > Reported-by: David Rientjes <rientjes@google.com>
Remove this.
> Signed-off-by: Michal Hocko <mhocko@suse.cz>
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