From: Peter Zijlstra <peterz@infradead.org>
To: Jason Low <jason.low2@hp.com>
Cc: torvalds@linux-foundation.org, paulmck@linux.vnet.ibm.com,
mingo@kernel.org, Waiman.Long@hp.com, davidlohr@hp.com,
linux-kernel@vger.kernel.org, riel@redhat.com,
akpm@linux-foundation.org, hpa@zytor.com, andi@firstfloor.org,
James.Bottomley@hansenpartnership.com, rostedt@goodmis.org,
tim.c.chen@linux.intel.com, aswin@hp.com, scott.norton@hp.com,
chegu_vinod@hp.com
Subject: Re: [RFC] Cancellable MCS spinlock rework
Date: Thu, 3 Jul 2014 09:31:48 +0200 [thread overview]
Message-ID: <20140703073148.GT19379@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <1404362358.8764.6.camel@j-VirtualBox>
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On Wed, Jul 02, 2014 at 09:39:18PM -0700, Jason Low wrote:
> And due to padding, the additional modification below reduces the
> size of struct rw_semaphore by 64 bits on my machine :)
>
>
> struct rw_semaphore {
> long count;
> - raw_spinlock_t wait_lock;
> struct list_head wait_list;
> + raw_spinlock_t wait_lock;
> #ifdef CONFIG_SMP
> + struct optimistic_spin_tail osq; /* spinner MCS lock */
> /*
> * Write owner. Used as a speculative check to see
> * if the owner is running on the cpu.
> */
> struct task_struct *owner;
> - struct optimistic_spin_tail osq; /* spinner MCS lock */
> #endif
> #ifdef CONFIG_DEBUG_LOCK_ALLOC
> struct lockdep_map dep_map;
>
Right, that might make sense.
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next prev parent reply other threads:[~2014-07-03 7:32 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-02 16:21 [RFC] Cancellable MCS spinlock rework Jason Low
2014-07-02 16:27 ` Peter Zijlstra
2014-07-02 16:59 ` Jason Low
2014-07-02 17:23 ` Peter Zijlstra
2014-07-02 17:30 ` Jason Low
2014-07-03 4:39 ` Jason Low
2014-07-03 7:31 ` Peter Zijlstra [this message]
2014-07-03 15:31 ` Linus Torvalds
2014-07-03 15:35 ` Linus Torvalds
2014-07-03 18:22 ` Jason Low
2014-07-03 7:31 ` Peter Zijlstra
2014-07-03 17:09 ` Davidlohr Bueso
2014-07-03 18:34 ` Jason Low
2014-07-03 20:35 ` Waiman Long
2014-07-03 20:51 ` Jason Low
2014-07-03 21:35 ` Waiman Long
2014-07-03 21:54 ` Jason Low
2014-07-04 7:49 ` Peter Zijlstra
2014-07-04 1:07 ` Jason Low
2014-07-04 7:51 ` Peter Zijlstra
2014-07-07 17:22 ` Jason Low
2014-07-04 9:17 ` Peter Zijlstra
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