linux-kernel - Re: [RFC,v2 3/3] sched: ignore task_h_load for CPU_NEWLY

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: <1f0bc6a4-7e17-98bf-2ef0-a805e32a5591@arm.com>
Date:   Wed, 15 Feb 2017 18:58:46 +0000
From:   Dietmar Eggemann <dietmar.eggemann@....com>
To:     Uladzislau Rezki <urezki@...il.com>,
        Peter Zijlstra <peterz@...radead.org>
Cc:     Ingo Molnar <mingo@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Uladzislau 2 Rezki <uladzislau2.rezki@...ymobile.com>
Subject: Re: [RFC,v2 3/3] sched: ignore task_h_load for CPU_NEWLY_IDLE

On 02/14/2017 06:28 PM, Uladzislau Rezki wrote:
>>>
>>> So that is useful information that should have been in the Changelog.
>>>
>>> OK, can you respin this patch with adjusted Changelog and taking Mike's
>>> feedback?
>>>
>> Yes, i will prepare a patch accordingly, no problem.
>>
>>>
>>> Also, I worry about the effects of this on !PREEMPT kernels, the first
>>> hunk (which explicitly states is about latency) should be under
>>> CONFIG_PREEMPT to match the similar case we already have in
>>> detach_tasks().

This one uses #ifdef CONFIG_PREEMPT whereas you use 
IS_ENABLED(CONFIG_PREEMPT). Is there a particular reason for this?

>>> But your second hunk, which ignores the actual load of tasks in favour
>>> of just moving _something_ already, is utterly dangerous if not coupled
>>> with these two other conditions, so arguably that too should be under
>>> CONFIG_PREEMPT.
>>>
>> I see your point. Will round both with CONFIG_PREEMPT.
>>
> I have upload a new patch, please find it here:
> https://lkml.org/lkml/2017/2/14/334
>