linux-kernel - Re: [PATCH cgroup/for-4.17 2/2] Subject: cgroup: Limit event generation frequency

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] [day] [month] [year] [list]

Message-ID: <20180426213514.GV1911913@devbig577.frc2.facebook.com>
Date:   Thu, 26 Apr 2018 14:35:14 -0700
From:   Tejun Heo <tj@...nel.org>
To:     Li Zefan <lizefan@...wei.com>, Johannes Weiner <hannes@...xchg.org>
Cc:     cgroups@...r.kernel.org, kernel-team@...com,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH cgroup/for-4.17 2/2] Subject: cgroup: Limit event
 generation frequency

On Fri, Mar 23, 2018 at 12:47:53PM -0700, Tejun Heo wrote:
> ".events" files generate file modified event to notify userland of
> possible new events.  Some of the events can be quite bursty
> (e.g. memory high event) and generating notification each time is
> costly and pointless.
> 
> This patch implements a event rate limit mechanism.  If a new
> notification is requested before 10ms has passed since the previous
> notification, the new notification is delayed till then.
> 
> As this only delays from the second notification on in a given close
> cluster of notifications, userland reactions to notifications
> shouldn't be delayed at all in most cases while avoiding notification
> storms.
> 
> Signed-off-by: Tejun Heo <tj@...nel.org>

Applied 1-2 to cgroup/for-4.18.

Thanks.

-- 
tejun