linux-kernel - Re: Potential scheduler regression

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 7 Jul 2017 16:55:27 -0400
From:   Ben Guthro <ben@...hro.net>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Mike Galbraith <efault@....de>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>
Subject: Re: Potential scheduler regression

On Wed, Jul 5, 2017 at 12:48 PM, Peter Zijlstra <peterz@...radead.org> wrote:
> On Wed, Jul 05, 2017 at 11:42:46AM -0400, Ben Guthro wrote:
>> Hello,
>>
>> I've been in the process of updating our kernel in our appliance VM
>> from an old LTS kernel (4.1.y) to something a bit more modern (4.9.y)
>> - and ran into a performance regression, when our QA team was running
>> some regression suites.
>>
>>
>> I bisect this behavior to the following commit, introduced in the 4.9
>> merge window:
>>
>
> Could you test a later kernel that includes commit:
>
>   1ad3aaf3fcd2 ("sched/core: Implement new approach to scale select_idle_cpu()")
>

(resend without html)

Apologies on the delay - it took a bit to get the machines, to run the test.

I am happy to report that the kernel at 1ad3aaf3fcd2, seems to regain
performance loss from 1b568f0aab, in our test environment.

Since 4.9 is an LTS kernel - is this appropriate to suggest to be
included in the linux-stable list?