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, a.p.zijlstra@chello.nl,
deepthi@linux.vnet.ibm.com, peterz@infradead.org,
rusty@rustcorp.com.au, heiko.carstens@de.ibm.com,
rostedt@goodmis.org, miltonm@bga.com,
srivatsa.bhat@linux.vnet.ibm.com, tj@kernel.org,
akpm@linux-foundation.org, svaidy@linux.vnet.ibm.com,
shli@kernel.org, tglx@linutronix.de, lig.fnst@cn.fujitsu.com,
anton@samba.org
Subject: Re: [PATCH 3/3] smp/ipi:Remove check around csd lock in handler for smp_call_function variants
Date: Mon, 8 Jul 2013 01:25:41 +0800 [thread overview]
Message-ID: <20130707172541.GA3218@udknight> (raw)
In-Reply-To: <51D99614.303@linux.vnet.ibm.com>
On Sun, Jul 07, 2013 at 09:53:48PM +0530, Preeti U Murthy wrote:
> > "
> > /*
> > * Unlocked CSDs are valid through generic_exec_single():
> > */
>
> I don't understand this comment. All callers of generic_exec_single()
> take the csd lock. So where is the scenario of csds being unlocked in
> generic_exec_single() before the call to
> arch_send_call_function_single_ipi() is made?
> Rather what is the above comment trying to say?
I have given the answer to this question in last reply.
I don't know whether it is right to make a assumption through
this way that what you do currently:
Find all the current api users, and drop all the robust codes,
despite the unpredictable future users.
Ok, I know the balance between "robust" vs "performance",
robust check codes will bring performance penalty in fastest
code path, but the "penalty" is neglectable sometimes for
modern CPU.
I decide to respect the MAINTAINER's decision to accept this
change or not.
Thanks.
prev parent reply other threads:[~2013-07-07 17:26 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-05 16:26 [PATCH 0/3] smp/ipi: Minor cleanups in smp_call_function variants Preeti U Murthy
2013-07-05 16:27 ` [PATCH 1/3] smp/ipi: Remove redundant cfd->cpumask_ipi mask Preeti U Murthy
2013-07-06 3:13 ` Wang YanQing
2013-07-06 5:29 ` Preeti U Murthy
2013-07-06 6:03 ` Wang YanQing
2013-07-07 16:45 ` Preeti U Murthy
2013-07-05 16:27 ` [PATCH 2/3] smp/ipi:Clarify ambiguous comments around deadlock scenarios in smp_call_function variants Preeti U Murthy
2013-07-06 6:12 ` Wang YanQing
2013-07-06 7:48 ` Preeti U Murthy
2013-07-06 19:48 ` Thomas Gleixner
2013-07-07 16:29 ` Preeti U Murthy
2013-07-05 16:27 ` [PATCH 3/3] smp/ipi:Remove check around csd lock in handler for " Preeti U Murthy
2013-07-06 5:45 ` Wang YanQing
2013-07-06 8:06 ` Preeti U Murthy
2013-07-06 14:21 ` Wang YanQing
2013-07-07 16:23 ` Preeti U Murthy
2013-07-07 17:25 ` Wang YanQing [this message]
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