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Date:   Tue, 12 Mar 2019 17:58:05 +0100
From:   Michal Hocko <mhocko@kernel.org>
To:     Sultan Alsawaf <sultan@kerneltoast.com>
Cc:     Suren Baghdasaryan <surenb@google.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Arve =?iso-8859-1?B?SGr4bm5lduVn?= <arve@android.com>,
        Todd Kjos <tkjos@android.com>,
        Martijn Coenen <maco@android.com>,
        Joel Fernandes <joel@joelfernandes.org>,
        Christian Brauner <christian@brauner.io>,
        Ingo Molnar <mingo@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        LKML <linux-kernel@vger.kernel.org>, devel@driverdev.osuosl.org,
        linux-mm <linux-mm@kvack.org>, Tim Murray <timmurray@google.com>
Subject: Re: [RFC] simple_lmk: Introduce Simple Low Memory Killer for Android
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On Tue 12-03-19 09:37:41, Sultan Alsawaf wrote:
> I have not had a chance to look at PSI yet, but
> unless a PSI-enabled solution allows allocations to reach the same point as when
> the OOM killer is invoked (which is contradictory to what it sets out to do),
> then it cannot take advantage of all of the alternative memory-reclaim means
> employed in the slowpath, and will result in killing a process before it is
> _really_ necessary.

One more note. The above is true, but you can also hit one of the
thrashing reclaim behaviors and reclaim last few pages again and again
with the whole system really sluggish. That is what PSI is trying to
help with.
-- 
Michal Hocko
SUSE Labs