Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1622844

Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to sync_exp_work_done()

Path csiph.com!aioe.org!news.servidellagleba.it!bofh.it!news.nic.it!robomod
From Peter Zijlstra <peterz@infradead.org>
Newsgroups linux.kernel
Subject Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to sync_exp_work_done()
Date Thu, 13 Apr 2017 11:20:02 +0200
Message-ID <tvJ50-Rx-15@gated-at.bofh.it> (permalink)
References <tvtMC-6Uu-3@gated-at.bofh.it> <tvtMC-6Uu-1@gated-at.bofh.it>
Dkim-Signature v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=afxel/oMStr8W2XCG5smOTz33o3UjUQXGB5TG2lUdwY=; b=CRGJxJvlzXq9tBWkMF6uIzRnv wcNVNCLsN/FIQv+IRmdXWiZN4PRkchMvVsDRcygjFk5Y5Oh1d50OOq8/SNgch4VjVn3H27JWSx8M8 k1uT1RGc1mjlH2ubzYF5hmWvAcQRj7MFV82PjsylEcv4u310COtkpL7fMogeRQ3kb8qBmSGnJJXBy ZaTpjWDNzlkTsPz8BmQ09Y+EApuTY3tGDFpKZnYTtlQ5BpDx9hnW/Iq32J63X8FPLSQgQchHuDJ13 6lxnxLvKKJreJGKs95o3gHzxsZX5h9mEHysZsikvfX4LIsTFasxBAPpMCvSKFaWjen3UEi7Qzlrdv AqoUsXZTg==;
MIME-Version 1.0
Content-Type text/plain; charset=us-ascii
Content-Disposition inline
User-Agent NeoMutt/20170113 (1.7.2)
Sender robomod@news.nic.it
List-ID <linux-kernel.vger.kernel.org>
X-Mailing-List linux-kernel@vger.kernel.org
Approved robomod@news.nic.it
Lines 11
Organization linux.* mail to news gateway
X-Original-Cc linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com
X-Original-Date Thu, 13 Apr 2017 11:18:32 +0200
X-Original-Message-ID <20170413091832.phnfppqjjy6sislo@hirez.programming.kicks-ass.net>
X-Original-References <20170412165441.GA17149@linux.vnet.ibm.com> <1492016149-18834-7-git-send-email-paulmck@linux.vnet.ibm.com>
X-Original-Sender linux-kernel-owner@vger.kernel.org
Xref csiph.com linux.kernel:1622844

Show key headers only | View raw


On Wed, Apr 12, 2017 at 09:55:43AM -0700, Paul E. McKenney wrote:
> However, a little future-proofing is a good thing,
> especially given that smp_mb__before_atomic() is only required to
> provide acquire semantics rather than full ordering.  This commit
> therefore adds smp_mb__after_atomic() after the atomic_long_inc()
> in sync_exp_work_done().

Oh!? As far as I'm away the smp_mb__{before,after}_atomic() really must
provide full MB, no confusion about that.

We have other primitives for acquire/release.

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to sync_exp_work_done() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-04-12 19:00 +0200
  Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() Peter Zijlstra <peterz@infradead.org> - 2017-04-13 11:20 +0200
    Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() Peter Zijlstra <peterz@infradead.org> - 2017-04-13 11:40 +0200
    Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-04-13 18:20 +0200
      Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() Peter Zijlstra <peterz@infradead.org> - 2017-04-13 18:30 +0200
        Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-04-13 19:00 +0200
          Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() Peter Zijlstra <peterz@infradead.org> - 2017-04-13 19:20 +0200
            Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-04-13 19:50 +0200
              Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() Peter Zijlstra <peterz@infradead.org> - 2017-04-13 20:00 +0200
                Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() Peter Zijlstra <peterz@infradead.org> - 2017-04-13 20:10 +0200
                Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-04-20 01:30 +0200
                Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-04-20 01:30 +0200
                Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() Peter Zijlstra <peterz@infradead.org> - 2017-04-20 13:20 +0200
                Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2017-04-20 17:10 +0200
                Re: [PATCH tip/core/rcu 07/13] rcu: Add smp_mb__after_atomic() to  sync_exp_work_done() Peter Zijlstra <peterz@infradead.org> - 2017-04-20 17:10 +0200

csiph-web