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Date: Sat, 6 Jul 2013 22:21:52 +0800
From: Wang YanQing <udknight@gmail.com>
To: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: mingo@elte.hu, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
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Subject: Re: [PATCH 3/3] smp/ipi:Remove check around csd lock in handler for
 smp_call_function variants
Message-ID: <20130706142152.GA2227@udknight>
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On Sat, Jul 06, 2013 at 01:36:27PM +0530, Preeti U Murthy wrote:
> Ideally it should be under a WARN_ON(). csd_unlock() has that WARN_ON().
> Unlocking a parameter which is not locked should be seen as a bug, which
> the above code is not doing. In fact it avoids it being reported as a bug.

Although I know what's your meaning, but just like the comment in code:

"
 /*                                                                                               
  * Unlocked CSDs are valid through generic_exec_single():                                        
  */
"

If the csd don't come from generic_exec_single, then
Unlocked CSDs maybe are not valid. So we check CSD_FLAG_LOCK
to avoid trigger the WARN_ON in csd_unlock.

Genric_exec_single's name imply it is a generic version,
you know, maybe we will have "special" version.

Thanks.