linux-kernel - Re: [PATCH v2 0/2] Replace PID bitmap allocation with IDR API

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: <1506645322.21121.106.camel@surriel.com>
Date:   Thu, 28 Sep 2017 20:35:22 -0400
From:   Rik van Riel <riel@...riel.com>
To:     Gargi Sharma <gs051095@...il.com>
Cc:     "Eric W. Biederman" <ebiederm@...ssion.com>,
        linux-kernel@...r.kernel.org, Julia Lawall <julia.lawall@...6.fr>,
        akpm@...ux-foundation.org, mingo@...nel.org,
        pasha.tatashin@...cle.com, ktkhai@...tuozzo.com,
        Oleg Nesterov <oleg@...hat.com>
Subject: Re: [PATCH v2 0/2] Replace PID bitmap allocation with IDR API

On Fri, 2017-09-29 at 01:35 +0530, Gargi Sharma wrote:
> On Thu, Sep 28, 2017 at 3:46 PM, Rik van Riel <riel@...riel.com>
> wrote:
> > On Fri, 2017-09-29 at 01:09 +0530, Gargi Sharma wrote:
> > 
> > > 1000 processes that just sleep and sit around without doing
> > > anything(100 second sleep and then exit).
> > 
> > Is that with or without your patches?
> > 
> > How does it compare to a kernel with(out) your patches?
> 
> Ah thanks for pointing this out. Those were without the patches.
> Here are the stats for easier comparison.
> 
> With Patches                 Without patches
> pstree
> real    0m0.542s            real    0m0.859s
> user    0m0.335s           user    0m0.536s
> sys    0m0.150s             sys    0m0.172s
> 
> ps
> real    0m0.722s            real    0m0.918s
> user    0m0.064s           user    0m0.100s
> sys    0m0.162s             sys    0m0.172s
> 
> readdir
> real    0m0.080s           real    0m0.092s
> user    0m0.000s          user    0m0.000s
> sys    0m0.021s            sys    0m0.020s

So your patches speed up the use of /proc?

I suspect pstree and ps benefit from the simplification
and speedup of find_pid_ns, which is called from
find_task_by_pid_ns.

That is great news.

-- 
All Rights Reversed.
Download attachment "signature.asc" of type "application/pgp-signature" (474 bytes)