linux-kernel - Re: [External] Re: [PATCH 0/2] Optimize the process of scanning CPU for some functions

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: <ce44cad1-8eab-4275-6c7a-6208265f3ae8@bytedance.com>
Date:   Mon, 24 Oct 2022 20:07:36 +0800
From:   Hao Jia <jiahao.os@...edance.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     mingo@...hat.com, mingo@...nel.org, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, dietmar.eggemann@....com,
        rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
        bristot@...hat.com, vschneid@...hat.com,
        mgorman@...hsingularity.net, linux-kernel@...r.kernel.org
Subject: Re: [External] Re: [PATCH 0/2] Optimize the process of scanning CPU
 for some functions



On 2022/10/24 Peter Zijlstra wrote:
> On Fri, Oct 21, 2022 at 02:15:56PM +0800, Hao Jia wrote:
>> These two patches optimize the process of scanning the CPU by
>> adjusting the search order or breaking the loop.
> 
> Is it really optimization, as in it now runs measurably faster, or just
> cleanups?


I'm very sorry that my description confused you.

Yes, these two patches should just be cleanups.

Reduce the number of attempts by adjusting the scan order or breaking 
the loop in time.
Just from code analysis, it will lead to a little optimization in most 
cases.
But they won't bring significant performance gains. So, it's just cleanups.


Thanks,
Hao