From: Jason Low <jason.low2@hp.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>,
Paul McKenney <paulmck@linux.vnet.ibm.com>,
Waiman Long <Waiman.Long@hp.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Rik van Riel <riel@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Davidlohr Bueso <davidlohr@hp.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Andi Kleen <andi@firstfloor.org>,
"Chandramouleeswaran, Aswin" <aswin@hp.com>,
"Norton, Scott J" <scott.norton@hp.com>,
chegu_vinod@hp.com
Subject: Re: [RFC][PATCH v2 5/5] mutex: Give spinners a chance to spin_on_owner if need_resched() triggered while queued
Date: Mon, 03 Feb 2014 23:13:12 -0800 [thread overview]
Message-ID: <1391497992.2774.17.camel@j-VirtualBox> (raw)
In-Reply-To: <20140203192525.GN8874@twins.programming.kicks-ass.net>
On Mon, 2014-02-03 at 20:25 +0100, Peter Zijlstra wrote:
> +void m_spin_unlock(struct m_spinlock **lock)
> +{
> + struct m_spinlock *node = this_cpu_ptr(&m_node);
> + struct m_spinlock *next;
> +
> + if (likely(cmpxchg(lock, node, NULL) == node))
> + return;
At this current point, (node->next != NULL) is a likely scenario.
Perhaps we can also add the following code here:
next = xchg(&node->next, NULL);
if (next) {
ACCESS_ONCE(next->locked) = 1;
return;
}
> + next = m_spin_wait_next(lock, node, NULL);
> + if (next)
> + ACCESS_ONCE(next->locked) = 1;
> +}
next prev parent reply other threads:[~2014-02-04 7:13 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-28 19:13 [PATCH v2 0/5] mutex: Mutex scalability patches Jason Low
2014-01-28 19:13 ` [PATCH v2 1/5] mutex: In mutex_can_spin_on_owner(), return false if task need_resched() Jason Low
2014-01-28 20:20 ` Paul E. McKenney
2014-01-28 22:01 ` Jason Low
2014-01-28 21:09 ` Davidlohr Bueso
2014-03-11 12:41 ` [tip:core/locking] locking/mutexes: Return false if task need_resched() in mutex_can_spin_on_owner() tip-bot for Jason Low
2014-01-28 19:13 ` [PATCH v2 2/5] mutex: Modify the way optimistic spinners are queued Jason Low
2014-01-28 20:23 ` Paul E. McKenney
2014-01-28 20:24 ` Paul E. McKenney
2014-01-28 21:17 ` Davidlohr Bueso
2014-01-28 22:10 ` Jason Low
2014-02-02 21:58 ` Paul E. McKenney
2014-03-11 12:41 ` [tip:core/locking] locking/mutexes: " tip-bot for Jason Low
2014-03-11 15:24 ` Jason Low
2014-03-11 15:33 ` Peter Zijlstra
2014-01-28 19:13 ` [PATCH v2 3/5] mutex: Unlock the mutex without the wait_lock Jason Low
2014-03-11 12:41 ` [tip:core/locking] locking/mutexes: " tip-bot for Jason Low
2014-03-12 12:24 ` Peter Zijlstra
2014-03-12 18:44 ` Jason Low
2014-03-13 7:28 ` [tip:core/locking] locking/mutex: Fix debug checks tip-bot for Peter Zijlstra
2014-01-28 19:13 ` [RFC][PATCH v2 4/5] mutex: Disable preemtion between modifying lock->owner and locking/unlocking mutex Jason Low
2014-01-28 20:54 ` Peter Zijlstra
2014-01-28 22:17 ` Jason Low
2014-01-28 19:13 ` [RFC][PATCH v2 5/5] mutex: Give spinners a chance to spin_on_owner if need_resched() triggered while queued Jason Low
2014-01-28 21:07 ` Peter Zijlstra
2014-01-28 22:51 ` Jason Low
2014-01-29 11:51 ` Peter Zijlstra
2014-01-31 3:29 ` Jason Low
2014-01-31 14:09 ` Peter Zijlstra
2014-01-31 20:01 ` Jason Low
2014-01-31 20:08 ` Peter Zijlstra
2014-02-02 21:01 ` Jason Low
2014-02-02 21:12 ` Peter Zijlstra
2014-02-03 18:39 ` Jason Low
2014-02-03 19:25 ` Peter Zijlstra
2014-02-03 20:55 ` Jason Low
2014-02-03 21:06 ` Peter Zijlstra
2014-02-03 21:56 ` Jason Low
2014-02-04 7:13 ` Jason Low [this message]
2014-02-02 22:02 ` Paul E. McKenney
2014-02-02 20:02 ` Peter Zijlstra
2014-02-05 21:44 ` Waiman Long
2014-02-06 14:04 ` Peter Zijlstra
2014-02-06 18:45 ` Waiman Long
2014-02-06 20:10 ` Norton, Scott J
2014-02-10 17:01 ` Peter Zijlstra
2014-02-06 17:44 ` Jason Low
2014-02-06 18:37 ` Waiman Long
2014-01-28 21:08 ` [PATCH v2 0/5] mutex: Mutex scalability patches Davidlohr Bueso
2014-01-28 23:11 ` Jason Low
-- strict thread matches above, loose matches on Subject: below --
2014-02-06 14:52 [RFC][PATCH v2 5/5] mutex: Give spinners a chance to spin_on_owner if need_resched() triggered while queued Daniel J Blueman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1391497992.2774.17.camel@j-VirtualBox \
--to=jason.low2@hp.com \
--cc=Waiman.Long@hp.com \
--cc=akpm@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=aswin@hp.com \
--cc=chegu_vinod@hp.com \
--cc=davidlohr@hp.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=riel@redhat.com \
--cc=scott.norton@hp.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).