From: Peter Zijlstra <peterz@infradead.org>
To: "Chen, Dennis (SRDC SW)" <Dennis1.Chen@amd.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
"paulmck@linux.vnet.ibm.com" <paulmck@linux.vnet.ibm.com>,
Paul Mackerras <paulus@samba.org>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Subject: Re: A quick view of the performance benchmark for semaphore-like and mutex
Date: Tue, 17 Apr 2012 12:09:43 +0200 [thread overview]
Message-ID: <1334657383.28150.78.camel@twins> (raw)
In-Reply-To: <491D6B4EAD0A714894D8AD22F4BDE043B15DCF@SCYBEXDAG03.amd.com>
On Tue, 2012-04-17 at 09:36 +0000, Chen, Dennis (SRDC SW) wrote:
> Just as a quick & rough test, with below changes based on mutex (almost the same as semaphore):
>
> --- /home/dennis/Linux/linux-3.3.2-sem/kernel/mutex.c 2012-04-17 14:59:49.823177615 +0800
> +++ ./mutex.c 2012-04-17 17:00:12.963059284 +0800
> @@ -140,6 +140,7 @@ __mutex_lock_common(struct mutex *lock,
> preempt_disable();
> mutex_acquire_nest(&lock->dep_map, subclass, 0, nest_lock, ip);
>
> +#if 0
> #ifdef CONFIG_MUTEX_SPIN_ON_OWNER
> /*
> * Optimistic spinning.
> @@ -195,6 +196,7 @@ __mutex_lock_common(struct mutex *lock,
> arch_mutex_cpu_relax();
> }
> #endif
> +#endif
> spin_lock_mutex(&lock->wait_lock, flags);
>
> debug_mutex_lock_common(lock, &waiter);
or you do:
echo NO_OWNER_SPIN > /debug/sched_features
next prev parent reply other threads:[~2012-04-17 10:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-17 9:36 A quick view of the performance benchmark for semaphore-like and mutex Chen, Dennis (SRDC SW)
2012-04-17 10:09 ` Peter Zijlstra [this message]
2012-04-17 10:12 ` Peter Zijlstra
2012-04-17 11:52 ` Chen, Dennis (SRDC SW)
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