linux-kernel - Re: [GIT PULL] cgroup changes for v4.18-rc1

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]

Date:   Wed, 6 Jun 2018 08:04:38 -0700
From:   Tejun Heo <tj@...nel.org>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Li Zefan <lizefan@...wei.com>,
        Johannes Weiner <hannes@...xchg.org>,
        cgroups <cgroups@...r.kernel.org>
Subject: Re: [GIT PULL] cgroup changes for v4.18-rc1

Hello, Linus.

On Tue, Jun 05, 2018 at 05:13:55PM -0700, Linus Torvalds wrote:
> On Tue, Jun 5, 2018 at 12:22 PM Tejun Heo <tj@...nel.org> wrote:
> >
> > * cgroup uses file modified events to notify certain events.  A rate
> >   limiting mechanism is added.
> 
> This "explanation" didn't really parse for me at all.
>
> I edited the merge message to something that I think is correct and
> made more sense to me.

Heh, yeah, yours reads a lot better.  Sorry about that.  The
background is that the mechanism was first added to generate
notifications on events like cgroup becoming empty, which is very low
frequency.  Since then, we've expanded its usage to cover things like
memory.high breached events which can be a lot higher frequency.

The notification implementation isn't super light weight, so the patch
ratelimits the notifications by capping minimum notification interval
interval to 10ms.

Thanks.

-- 
tejun