linux-kernel - Re: [PATCH] sched: fix env->src

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: <CAKfTPtDrTyof40Lk7MzdqEon2dkN=RZNEvP5BQSJVKP-EYsCXw@mail.gmail.com>
Date:	Wed, 13 Feb 2013 18:49:03 +0100
From:	Vincent Guittot <vincent.guittot@...aro.org>
To:	Damien Wyart <damien.wyart@...il.com>
Cc:	linux-kernel@...r.kernel.org, linaro-dev@...ts.linaro.org,
	peterz@...radead.org, mingo@...nel.org,
	Frederic Weisbecker <fweisbec@...il.com>
Subject: Re: [PATCH] sched: fix env->src_cpu for active migration

On 13 February 2013 15:28, Vincent Guittot <vincent.guittot@...aro.org> wrote:
> On 13 February 2013 15:08, Damien Wyart <damien.wyart@...il.com> wrote:
>> * Vincent Guittot <vincent.guittot@...aro.org> [2013-02-13 13:08]:
>>> Damien,
>>> Regarding your sched_domain config and especially the flags field, you
>>> should not be impacted by my patch because
>>> - need_active_balance is the only new place that use env->src_cpu in
>>> the load_balance function
>>> - and your machine will never test the condition: "env->src_cpu >
>>> env->dst_cpu" in need_active_balance because  SD_ASYM_PACKING is not
>>> set in your config
>>
>>> Have you tested the patch with others that could have modified the
>>> load_balance function ?
>>
>> Yes, sorry, I should have been more precise in my initial report: your
>> patch was not applied on top of vanilla 3.8-rc7, but a few other patches
>> were also present. Seems the ones impacting load_balance are from
>> Frederic's nohz work
>> (http://git.kernel.org/?p=linux/kernel/git/frederic/linux-dynticks.git;a=shortlog;h=refs/heads/3.8-rc6-nohz4)
>>
>
> ok
> thanks for the pointer. i'm going to have a look
>
>
>> The patches from there modifying load_balance are:
>> - "sched: Update nohz rq clock before searching busiest group on load balancing"
>> - "sched: Update clock of nohz busiest rq before balancing"
>>
>> In this test, I did not use any kernel parameter related to this
>> patchset (full_nohz, etc.).
>>
>> I am adding Frederic in Cc, not sure if the breakage is to be
>> investigated on your side or his...
>
> probably both

I have look into Frederic's tree but i didn't find any reason that
could explain your problem. May be Frederic will have some ideas
I have also tested his branch with and without my patch and both
kernel are booting (on an ARM platform without using the full_nohz
feature ).
I have faced a conflict when i have applied my patch on his branch as
we insert code at the same place. You should have faced the same
conflict. How have you solved it ?

Vincent
>
>>
>>
>> Thanks for your explanations,
>> --
>> Damien
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/