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Date: Mon, 18 Feb 2013 22:16:05 +0530
From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
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To: Steven Rostedt <rostedt@goodmis.org>
CC: Michel Lespinasse <walken@google.com>, tglx@linutronix.de,
        peterz@infradead.org, tj@kernel.org, oleg@redhat.com,
        paulmck@linux.vnet.ibm.com, rusty@rustcorp.com.au, mingo@kernel.org,
        akpm@linux-foundation.org, namhyung@kernel.org,
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        vincent.guittot@linaro.org
Subject: Re: [PATCH v6 04/46] percpu_rwlock: Implement the core design of
 Per-CPU Reader-Writer Locks
References: <20130218123714.26245.61816.stgit@srivatsabhat.in.ibm.com> <20130218123856.26245.46705.stgit@srivatsabhat.in.ibm.com> <CANN689F9S7c1M8+cEpz3tsxGF34+NTRBLvxgPUOtbvav5u+RRA@mail.gmail.com> <5122551E.1080703@linux.vnet.ibm.com> <1361205087.23152.159.camel@gandalf.local.home>
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On 02/18/2013 10:01 PM, Steven Rostedt wrote:
> On Mon, 2013-02-18 at 21:51 +0530, Srivatsa S. Bhat wrote:
>> Hi Michel,
> 
>> Yes.. I don't think we can avoid that. Moreover, since we _want_ unfair
>> reader/writer semantics to allow flexible locking rules and guarantee
>> deadlock-safety, having a recursive reader side is not even an issue, IMHO.
> 
> Recursive unfair reader lock may guarantee deadlock-safety, but
> remember, it adds a higher probability of live-locking the write_lock.
> Which is another argument to keep this separate to cpu hotplug only.
> 

True.
 
Regards,
Srivatsa S. Bhat