linux-kernel - Re: 2.6.27.8 scheduler bug - threads not being scheduled for long periods

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: <20090105230218.GC20319@sgi.com>
Date:	Mon, 5 Jan 2009 17:02:18 -0600
From:	Dimitri Sivanich <sivanich@....com>
To:	Peter Zijlstra <peterz@...radead.org>,
	linux-kernel@...r.kernel.org, tony.luck@...el.com
Cc:	Ingo Molnar <mingo@...e.hu>, Mike Galbraith <efault@....de>,
	Srivatsa Vaddagiri <vatsa@...ux.vnet.ibm.com>,
	Gregory Haskins <ghaskins@...ell.com>,
	Greg KH <greg@...ah.com>, Nick Piggin <npiggin@...e.de>,
	Robin Holt <holt@....com>
Subject: Re: 2.6.27.8 scheduler bug - threads not being scheduled for long periods

Peter,

On Mon, Jan 05, 2009 at 04:36:21PM -0600, Dimitri Sivanich wrote:
> And sure enough, the rq->clock is sometimes going backwards.
> 
> The comment for sched_clock() in arch/ia64/kernel/head.S:
>  * Return a CPU-local timestamp in nano-seconds.  This timestamp is
>  * NOT synchronized across CPUs its return value must never be
>  * compared against the values returned on another CPU.  The usage in
>  * kernel/sched.c ensures that.
> 
> We will try this with CONFIG_HAVE_UNSTABLE_SCHED_CLOCKS.
>

The testcase does indeed run with CONFIG_HAVE_UNSTABLE_SCHED_CLOCKS configured.
--
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/