linux-kernel - Re: [rfc patch] Re: sched: incorrect argument used in task

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: <20061117192052.GA23272@elte.hu>
Date:	Fri, 17 Nov 2006 20:20:52 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Mike Galbraith <efault@....de>
Cc:	"Chen, Kenneth W" <kenneth.w.chen@...el.com>,
	nickpiggin@...oo.com.au,
	"Siddha, Suresh B" <suresh.b.siddha@...el.com>,
	linux-kernel@...r.kernel.org, Andrew Morton <akpm@...l.org>
Subject: Re: [rfc patch] Re: sched: incorrect argument used in task_hot()


* Mike Galbraith <efault@....de> wrote:

> One way to improve granularity, and eliminate the possibility of 
> p->last_run being > rq->timestamp_tast_tick, and thereby short 
> circuiting the evaluation of cache_hot_time, is to cache the last 
> return of sched_clock() at both tick and sched times, and use that 
> value as our reference instead of the absolute time of the tick.  It 
> won't totally eliminate skew, but it moves the reference point closer 
> to the current time on the remote cpu.
> 
> Looking for a good place to do this, I chose update_cpu_clock().

looks good to me - thus we will update the timestamp not only in the 
timer tick, but also upon every context-switch (when we acquire 
sched_clock() value anyway). Lets try this in -mm?

Acked-by: Ingo Molnar <mingo@...e.hu>

	Ingo
-
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/