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Date: Thu, 19 Oct 2017 13:18:32 +0300
From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Shakeel Butt <shakeelb@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Vlastimil Babka <vbabka@suse.cz>, Michal Hocko <mhocko@suse.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>, Minchan Kim <minchan@kernel.org>,
        Yisheng Xie <xieyisheng1@huawei.com>, Ingo Molnar <mingo@kernel.org>,
        Greg Thelen <gthelen@google.com>, Hugh Dickins <hughd@google.com>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: mlock: remove lru_add_drain_all()
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On Wed, Oct 18, 2017 at 04:17:30PM -0700, Shakeel Butt wrote:
> Recently we have observed high latency in mlock() in our generic
> library and noticed that users have started using tmpfs files even
> without swap and the latency was due to expensive remote LRU cache
> draining.

Hm. Isn't the point of mlock() to pay price upfront and make execution
smoother after this?

With this you shift latency onto reclaim (and future memory allocation).

I'm not sure if it's a win.

-- 
 Kirill A. Shutemov