linux-kernel - Re: [PATCH] configure HAVE_UNSTABLE_SCHED_CLOCK for SGI

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: <20090115184832.GE10674@kroah.com>
Date:	Thu, 15 Jan 2009 10:48:32 -0800
From:	Greg KH <greg@...ah.com>
To:	Dimitri Sivanich <sivanich@....com>
Cc:	linux-ia64@...r.kernel.org, Tony Luck <tony.luck@...el.com>,
	linux-kernel@...r.kernel.org,
	Peter Zijlstra <peterz@...radead.org>,
	Gregory Haskins <ghaskins@...ell.com>,
	Nick Piggin <npiggin@...e.de>, Tony Luck <tony.luck@...il.com>,
	Robin Holt <holt@....com>
Subject: Re: [PATCH] configure HAVE_UNSTABLE_SCHED_CLOCK for SGI_SN systems

On Tue, Jan 06, 2009 at 10:27:41AM -0600, Dimitri Sivanich wrote:
> Turn on CONFIG_HAVE_UNSTABLE_SCHED_CLOCK for SGI_SN.
> 
> SGI Altix has unsynchronized itc clocks.  This results in rq->clock
> occasionally being set to a time in the past by a remote cpu.
> 
> Note that it is possible that this problem may exist for other ia64
> machines as well, based on the following 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.
> 
> 
> Signed-off-by: Dimitri Sivanich <sivanich@....com>
> 
> ---
> 
> Greg, if everyone is OK with this patch, this should also be applied
> to all stable trees starting with 2.6.26.

What is the status of this going into Linus's tree?

thanks,

greg k-h
--
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/