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    SubjectRe: [PATCH] mm,oom: Bring OOM notifier callbacks to outside of OOM killer.
    On Tue 03-07-18 09:01:01, Paul E. McKenney wrote:
    > On Tue, Jul 03, 2018 at 09:24:13AM +0200, Michal Hocko wrote:
    > > On Mon 02-07-18 14:37:14, Paul E. McKenney wrote:
    > > [...]
    > > > commit d2b8d16b97ac2859919713b2d98b8a3ad22943a2
    > > > Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    > > > Date: Mon Jul 2 14:30:37 2018 -0700
    > > >
    > > > rcu: Remove OOM code
    > > >
    > > > There is reason to believe that RCU's OOM code isn't really helping
    > > > that much, given that the best it can hope to do is accelerate invoking
    > > > callbacks by a few seconds, and even then only if some CPUs have no
    > > > non-lazy callbacks, a condition that has been observed to be rare.
    > > > This commit therefore removes RCU's OOM code. If this causes problems,
    > > > it can easily be reinserted.
    > > >
    > > > Reported-by: Michal Hocko <mhocko@kernel.org>
    > > > Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
    > > > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    > >
    > > I would also note that waiting in the notifier might be a problem on its
    > > own because we are holding the oom_lock and the system cannot trigger
    > > the OOM killer while we are holding it and waiting for oom_callback_wq
    > > event. I am not familiar with the code to tell whether this can deadlock
    > > but from a quick glance I _suspect_ that we might depend on __rcu_reclaim
    > > and basically an arbitrary callback so no good.
    > >
    > > Acked-by: Michal Hocko <mhocko@suse.com>
    > >
    > > Thanks!
    >
    > Like this?

    Thanks!
    --
    Michal Hocko
    SUSE Labs

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