linux-kernel - Re: [PATCH v5 2/2] ipc/msg: mitigate the lock contention with percpu counter

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:   Fri, 09 Sep 2022 09:11:16 -0700
From:   Tim Chen <tim.c.chen@...ux.intel.com>
To:     Jiebin Sun <jiebin.sun@...el.com>, akpm@...ux-foundation.org,
        vasily.averin@...ux.dev, shakeelb@...gle.com, dennis@...nel.org,
        tj@...nel.org, cl@...ux.com, ebiederm@...ssion.com,
        legion@...nel.org, manfred@...orfullife.com,
        alexander.mikhalitsyn@...tuozzo.com, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Cc:     tim.c.chen@...el.com, feng.tang@...el.com, ying.huang@...el.com,
        tianyou.li@...el.com, wangyang.guo@...el.com
Subject: Re: [PATCH v5 2/2] ipc/msg: mitigate the lock contention with
 percpu counter

On Sat, 2022-09-10 at 04:36 +0800, Jiebin Sun wrote:
> The msg_bytes and msg_hdrs atomic counters are frequently
> updated when IPC msg queue is in heavy use, causing heavy
> cache bounce and overhead. Change them to percpu_counter
> greatly improve the performance. Since there is one percpu
> struct per namespace, additional memory cost is minimal.
> Reading of the count done in msgctl call, which is infrequent.
> So the need to sum up the counts in each CPU is infrequent.
> 
> Apply the patch and test the pts/stress-ng-1.4.0
> -- system v message passing (160 threads).
> 
> Score gain: 3.99x
> 
> CPU: ICX 8380 x 2 sockets
> Core number: 40 x 2 physical cores
> Benchmark: pts/stress-ng-1.4.0
> -- system v message passing (160 threads)

Reviewed-by: Tim Chen <tim.c.chen@...ux.intel.com>

> 
> Signed-off-by: Jiebin Sun <jiebin.sun@...el.com>
> ---
>