From: Peter Zijlstra <peterz@infradead.org>
To: Waiman Long <waiman.long@hp.com>
Cc: arnd@arndb.de, linux-arch@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org, rostedt@goodmis.org,
akpm@linux-foundation.org, walken@google.com,
andi@firstfloor.org, riel@redhat.com, paulmck@linux.vnet.ibm.com,
torvalds@linux-foundation.org, oleg@redhat.com,
Peter Zijlstra <peterz@infradead.org>
Subject: [RFC][PATCH 0/7] locking: qspinlock
Date: Mon, 10 Mar 2014 16:42:36 +0100 [thread overview]
Message-ID: <20140310154236.038181843@infradead.org> (raw)
Hi Waiman,
I promised you this series a number of days ago; sorry for the delay I've been
somewhat unwell :/
That said, these few patches start with a (hopefully) simple and correct form
of the queue spinlock, and then gradually build upon it, explaining each
optimization as we go.
Having these optimizations as separate patches helps twofold; firstly it makes
one aware of which exact optimizations were done, and secondly it allows one to
proove or disprove any one step; seeing how they should be mostly identity
transforms.
The resulting code is near to what you posted I think; however it has one
atomic op less in the pending wait-acquire case for NR_CPUS != huge. It also
doesn't do lock stealing; its still perfectly fair afaict.
Have I missed any tricks from your code?
The patches apply to tip/master + lkml.kernel.org/r/20140210195820.834693028@infradead.org
I've yet to look at the paravirt stuff.
next reply other threads:[~2014-03-10 16:02 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-10 15:42 Peter Zijlstra [this message]
2014-03-10 15:42 ` [RFC][PATCH 1/7] qspinlock: Introducing a 4-byte queue spinlock implementation Peter Zijlstra
2014-03-10 15:42 ` Peter Zijlstra
2014-03-13 13:07 ` Peter Zijlstra
2014-03-10 15:42 ` [RFC][PATCH 2/7] qspinlock, x86: Enable x86 to use queue spinlock Peter Zijlstra
2014-03-10 15:42 ` Peter Zijlstra
2014-03-10 15:42 ` [RFC][PATCH 3/7] qspinlock: Add pending bit Peter Zijlstra
2014-03-10 15:42 ` Peter Zijlstra
2014-03-10 15:42 ` [RFC][PATCH 4/7] x86: Add atomic_test_and_set_bit() Peter Zijlstra
2014-03-10 15:42 ` [RFC][PATCH 5/7] qspinlock: Optimize the pending case Peter Zijlstra
2014-03-10 15:42 ` Peter Zijlstra
2014-03-10 15:42 ` [RFC][PATCH 6/7] qspinlock: Optimize xchg_tail Peter Zijlstra
2014-03-10 15:42 ` Peter Zijlstra
2014-03-10 15:42 ` [RFC][PATCH 7/7] qspinlock: Optimize for smaller NR_CPUS Peter Zijlstra
2014-03-10 15:42 ` Peter Zijlstra
2014-03-11 10:45 ` [RFC][PATCH 0/7] locking: qspinlock Ingo Molnar
2014-03-11 11:02 ` Peter Zijlstra
2014-03-11 11:04 ` Ingo Molnar
2014-03-12 3:17 ` Waiman Long
2014-03-12 6:24 ` Peter Zijlstra
2014-03-12 15:32 ` Peter Zijlstra
2014-03-12 19:00 ` Waiman Long
2014-03-12 2:31 ` Dave Chinner
2014-03-12 3:11 ` Steven Rostedt
2014-03-12 4:26 ` Dave Chinner
2014-03-12 10:07 ` Steven Rostedt
2014-03-12 15:57 ` Peter Zijlstra
2014-03-12 16:06 ` Linus Torvalds
2014-03-12 16:19 ` Steven Rostedt
2014-03-12 16:19 ` Steven Rostedt
2014-03-12 16:23 ` Peter Zijlstra
2014-03-12 16:23 ` Peter Zijlstra
2014-03-12 6:15 ` Peter Zijlstra
2014-03-12 23:48 ` Dave Chinner
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=20140310154236.038181843@infradead.org \
--to=peterz@infradead.org \
--cc=akpm@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=arnd@arndb.de \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=oleg@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=riel@redhat.com \
--cc=rostedt@goodmis.org \
--cc=torvalds@linux-foundation.org \
--cc=waiman.long@hp.com \
--cc=walken@google.com \
--cc=x86@kernel.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).