linux-kernel - Re: [PATCH] mm: mlock: remove lru_add_drain

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20171019101832.xli25kizn3y55pbq@node.shutemov.name>
Date:   Thu, 19 Oct 2017 13:18:32 +0300
From:   "Kirill A. Shutemov" <kirill@...temov.name>
To:     Shakeel Butt <shakeelb@...gle.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Michal Hocko <mhocko@...e.com>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Minchan Kim <minchan@...nel.org>,
        Yisheng Xie <xieyisheng1@...wei.com>,
        Ingo Molnar <mingo@...nel.org>,
        Greg Thelen <gthelen@...gle.com>,
        Hugh Dickins <hughd@...gle.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mm: mlock: remove lru_add_drain_all()

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