Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753575AbbGAKEW (ORCPT ); Wed, 1 Jul 2015 06:04:22 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:50016 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750935AbbGAKEO (ORCPT ); Wed, 1 Jul 2015 06:04:14 -0400 Date: Wed, 1 Jul 2015 12:03:52 +0200 From: Peter Zijlstra To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, laijs@cn.fujitsu.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, dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com, bobby.prani@gmail.com Subject: Re: [PATCH RFC tip/core/rcu 2/5] rcu: Short-circuit normal GPs via expedited GPs Message-ID: <20150701100352.GO19282@twins.programming.kicks-ass.net> References: <20150630214805.GA7795@linux.vnet.ibm.com> <1435700910-9104-1-git-send-email-paulmck@linux.vnet.ibm.com> <1435700910-9104-2-git-send-email-paulmck@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1435700910-9104-2-git-send-email-paulmck@linux.vnet.ibm.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1449 Lines: 47 On Tue, Jun 30, 2015 at 02:48:27PM -0700, Paul E. McKenney wrote: > @@ -2121,17 +2137,24 @@ static int __noreturn rcu_gp_kthread(void *arg) > TPS("fqswait")); > rsp->gp_state = RCU_GP_WAIT_FQS; > ret = wait_event_interruptible_timeout(rsp->gp_wq, > - ((gf = READ_ONCE(rsp->gp_flags)) & > - RCU_GP_FLAG_FQS) || > - (!READ_ONCE(rnp->qsmask) && > - !rcu_preempt_blocked_readers_cgp(rnp)), > - j); > + ((gf = READ_ONCE(rsp->gp_flags)) & > + RCU_GP_FLAG_FQS) || > + (!READ_ONCE(rnp->qsmask) && > + !rcu_preempt_blocked_readers_cgp(rnp)) || > + rcu_exp_gp_seq_done(rsp->exp_rsp, > + rsp->gp_exp_snap), > + j); How about using a helper function there? static inline bool rcu_gp_done(rsp, rnp) { /* Forced Quiescent State complete */ if (READ_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) return true; /* QS not masked and not blocked by preempted readers */ if (!READ_ONCE(rnp->qsmask) && !rcu_preempt_blocked_readers_cgp(rnp)) return true; /* Expedited Grace Period completed */ if (rcu_exp_gp_seq_done(rsp)) return true; return false; } ret = wait_event_interruptible_timeout(rsp->gp_wq, rcu_gp_done(rsp, rnp), j); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/