linux-kernel - Re: [PATCH] [RFC] Potential fix for leapsecond caused futex related load spikes

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Message-ID: <4FF088B9.1000308@us.ibm.com>
Date:	Sun, 01 Jul 2012 10:28:25 -0700
From:	John Stultz <johnstul@...ibm.com>
To:	Prarit Bhargava <prarit@...hat.com>
CC:	Linux Kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] [RFC] Potential fix for leapsecond caused futex related
 load spikes

On 07/01/2012 09:56 AM, Prarit Bhargava wrote:
>
> John, the issue is that clock_was_set calls on_each_cpu() -- which cannot be
> called from interrupt context as it calls smp_call_function_many().
>
> I don't think you can call call_was_set() from update_wall_time() as
> update_wall_time() is called in interrupt context.
>

Thanks for pointing this out.  Ben Blum also mentioned this last night, 
but I missed the atomic bit instead of the xtime_lock issue.

Reworking the patch now.

thanks again
-john

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