From: Davidlohr Bueso <dave@stgolabs.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <Waiman.Long@hpe.com>, Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, x86@kernel.org,
linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-s390@vger.kernel.org, linux-arch@vger.kernel.org,
Jason Low <jason.low2@hp.com>, Dave Chinner <david@fromorbit.com>,
Scott J Norton <scott.norton@hpe.com>,
Douglas Hatch <doug.hatch@hpe.com>
Subject: Re: [RFC PATCH-tip v2 1/6] locking/osq: Make lock/unlock proper acquire/release barrier
Date: Wed, 15 Jun 2016 11:27:24 -0700 [thread overview]
Message-ID: <20160615182724.GD2094@linux-80c1.suse> (raw)
In-Reply-To: <20160615171250.GO30921@twins.programming.kicks-ass.net>
On Wed, 15 Jun 2016, Peter Zijlstra wrote:
>In any case, its fairly simple to cure, just add
>smp_acquire__after_ctrl_dep() at the end. If we bail because
>need_resched() we don't need the acquire I think.
I was just considering this for your smp_cond_acquire/smp_cond_load_acquire
rework, so yeah I guess an smp_acquire__after_ctrl_dep would be a nice
compromise.
However, I was always under the impression that races with node->locked were
rather harmless (as indicated in the mentioned commit) -- which is why ->locked
are simple load/stores, with the exception of the unqueueing -- but yeah, that's
not even paired.
Thanks,
Davidlohr
WARNING: multiple messages have this Message-ID (diff)
From: Davidlohr Bueso <dave@stgolabs.net>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Waiman Long <Waiman.Long@hpe.com>, Ingo Molnar <mingo@redhat.com>,
linux-kernel@vger.kernel.org, x86@kernel.org,
linux-alpha@vger.kernel.org, linux-ia64@vger.kernel.org,
linux-s390@vger.kernel.org, linux-arch@vger.kernel.org,
Jason Low <jason.low2@hp.com>, Dave Chinner <david@fromorbit.com>,
Scott J Norton <scott.norton@hpe.com>,
Douglas Hatch <doug.hatch@hpe.com>
Subject: Re: [RFC PATCH-tip v2 1/6] locking/osq: Make lock/unlock proper acquire/release barrier
Date: Wed, 15 Jun 2016 18:27:24 +0000 [thread overview]
Message-ID: <20160615182724.GD2094@linux-80c1.suse> (raw)
In-Reply-To: <20160615171250.GO30921@twins.programming.kicks-ass.net>
On Wed, 15 Jun 2016, Peter Zijlstra wrote:
>In any case, its fairly simple to cure, just add
>smp_acquire__after_ctrl_dep() at the end. If we bail because
>need_resched() we don't need the acquire I think.
I was just considering this for your smp_cond_acquire/smp_cond_load_acquire
rework, so yeah I guess an smp_acquire__after_ctrl_dep would be a nice
compromise.
However, I was always under the impression that races with node->locked were
rather harmless (as indicated in the mentioned commit) -- which is why ->locked
are simple load/stores, with the exception of the unqueueing -- but yeah, that's
not even paired.
Thanks,
Davidlohr
next prev parent reply other threads:[~2016-06-15 18:27 UTC|newest]
Thread overview: 101+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-14 22:48 [RFC PATCH-tip v2 0/6] locking/rwsem: Enable reader optimistic spinning Waiman Long
2016-06-14 22:48 ` Waiman Long
2016-06-14 22:48 ` [RFC PATCH-tip v2 1/6] locking/osq: Make lock/unlock proper acquire/release barrier Waiman Long
2016-06-14 22:48 ` Waiman Long
2016-06-15 8:04 ` Boqun Feng
2016-06-15 8:04 ` Boqun Feng
2016-06-15 17:18 ` Peter Zijlstra
2016-06-15 17:18 ` Peter Zijlstra
2016-06-15 19:01 ` Waiman Long
2016-06-15 19:01 ` Waiman Long
2016-06-15 19:01 ` Waiman Long
2016-06-16 2:19 ` Boqun Feng
2016-06-16 2:19 ` Boqun Feng
2016-06-16 10:16 ` Will Deacon
2016-06-16 10:16 ` Will Deacon
2016-06-16 21:35 ` Waiman Long
2016-06-16 21:35 ` Waiman Long
2016-06-16 21:35 ` Waiman Long
2016-06-17 0:48 ` Boqun Feng
2016-06-17 0:48 ` Boqun Feng
2016-06-17 15:26 ` Waiman Long
2016-06-17 15:26 ` Waiman Long
2016-06-17 15:26 ` Waiman Long
2016-06-17 15:45 ` Will Deacon
2016-06-17 15:45 ` Will Deacon
2016-06-17 18:17 ` Waiman Long
2016-06-17 18:17 ` Waiman Long
2016-06-17 18:17 ` Waiman Long
2016-06-18 8:46 ` Boqun Feng
2016-06-18 8:46 ` Boqun Feng
2016-06-20 7:59 ` Will Deacon
2016-06-20 7:59 ` Will Deacon
2016-06-15 16:56 ` Davidlohr Bueso
2016-06-15 16:56 ` Davidlohr Bueso
2016-06-15 17:12 ` Peter Zijlstra
2016-06-15 17:12 ` Peter Zijlstra
2016-06-15 18:27 ` Davidlohr Bueso [this message]
2016-06-15 18:27 ` Davidlohr Bueso
2016-06-15 18:40 ` Peter Zijlstra
2016-06-15 18:40 ` Peter Zijlstra
2016-06-15 18:56 ` Davidlohr Bueso
2016-06-15 18:56 ` Davidlohr Bueso
2016-06-17 1:11 ` Davidlohr Bueso
2016-06-17 1:11 ` Davidlohr Bueso
2016-06-17 14:28 ` Waiman Long
2016-06-17 14:28 ` Waiman Long
2016-06-17 14:28 ` Waiman Long
2016-06-17 16:29 ` Davidlohr Bueso
2016-06-17 16:29 ` Davidlohr Bueso
2016-06-17 16:46 ` Davidlohr Bueso
2016-06-17 16:46 ` Davidlohr Bueso
2016-06-15 19:08 ` Waiman Long
2016-06-15 19:08 ` Waiman Long
2016-06-15 19:08 ` Waiman Long
2016-06-15 20:04 ` Waiman Long
2016-06-15 20:04 ` Waiman Long
2016-06-15 20:04 ` Waiman Long
2016-06-15 21:59 ` Peter Zijlstra
2016-06-15 21:59 ` Peter Zijlstra
2016-06-14 22:48 ` [RFC PATCH-tip v2 2/6] locking/rwsem: Stop active read lock ASAP Waiman Long
2016-06-14 22:48 ` Waiman Long
2016-06-15 17:22 ` Peter Zijlstra
2016-06-15 17:22 ` Peter Zijlstra
2016-06-15 19:17 ` Waiman Long
2016-06-15 19:17 ` Waiman Long
2016-06-15 19:17 ` Waiman Long
2016-06-16 2:14 ` Davidlohr Bueso
2016-06-16 2:14 ` Davidlohr Bueso
2016-06-16 21:25 ` Waiman Long
2016-06-16 21:25 ` Waiman Long
2016-06-16 21:25 ` Waiman Long
2016-06-14 22:48 ` [RFC PATCH-tip v2 3/6] locking/rwsem: Enable count-based spinning on reader Waiman Long
2016-06-14 22:48 ` Waiman Long
2016-06-15 17:38 ` Peter Zijlstra
2016-06-15 17:38 ` Peter Zijlstra
2016-06-15 19:28 ` Waiman Long
2016-06-15 19:28 ` Waiman Long
2016-06-15 19:28 ` Waiman Long
2016-06-14 22:48 ` [RFC PATCH-tip v2 4/6] locking/rwsem: move down rwsem_down_read_failed function Waiman Long
2016-06-14 22:48 ` Waiman Long
2016-06-15 17:40 ` Peter Zijlstra
2016-06-15 17:40 ` Peter Zijlstra
2016-06-15 19:21 ` Waiman Long
2016-06-15 19:21 ` Waiman Long
2016-06-15 19:21 ` Waiman Long
2016-06-14 22:48 ` [RFC PATCH-tip v2 5/6] locking/rwsem: Change RWSEM_WAITING_BIAS for better disambiguation Waiman Long
2016-06-14 22:48 ` Waiman Long
2016-06-15 17:43 ` Peter Zijlstra
2016-06-15 17:43 ` Peter Zijlstra
2016-06-15 19:31 ` Waiman Long
2016-06-15 19:31 ` Waiman Long
2016-06-15 19:31 ` Waiman Long
2016-06-15 21:57 ` Peter Zijlstra
2016-06-15 21:57 ` Peter Zijlstra
2016-06-15 17:45 ` Peter Zijlstra
2016-06-15 17:45 ` Peter Zijlstra
2016-06-15 19:35 ` Waiman Long
2016-06-15 19:35 ` Waiman Long
2016-06-15 19:35 ` Waiman Long
2016-06-14 22:48 ` [RFC PATCH-tip v2 6/6] locking/rwsem: Enable spinning readers Waiman Long
2016-06-14 22:48 ` Waiman Long
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=20160615182724.GD2094@linux-80c1.suse \
--to=dave@stgolabs.net \
--cc=Waiman.Long@hpe.com \
--cc=david@fromorbit.com \
--cc=doug.hatch@hpe.com \
--cc=jason.low2@hp.com \
--cc=linux-alpha@vger.kernel.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-ia64@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-s390@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=scott.norton@hpe.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.