From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752693AbcGONmJ (ORCPT ); Fri, 15 Jul 2016 09:42:09 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53513 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751690AbcGONmE (ORCPT ); Fri, 15 Jul 2016 09:42:04 -0400 Date: Fri, 15 Jul 2016 15:42:22 +0200 From: Oleg Nesterov To: Peter Zijlstra Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, tj@kernel.org, paulmck@linux.vnet.ibm.com, john.stultz@linaro.org, dimitrysh@google.com, romlem@google.com, ccross@google.com, tkjos@google.com Subject: Re: [PATCH 2/2] locking/percpu-rwsem: Introduce bias knob Message-ID: <20160715134222.GA28589@redhat.com> References: <20160714182545.786693675@infradead.org> <20160714183022.336211504@infradead.org> <20160714184351.GA18388@redhat.com> <20160714192018.GM30154@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160714192018.GM30154@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.18 (2008-05-17) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Fri, 15 Jul 2016 13:42:03 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/14, Peter Zijlstra wrote: > > +void rcu_sync_sabotage(struct rcu_sync *rsp) > +{ > + rsp->gp_count++; > + rsp->gp_state = !GP_IDLE; > +} Ah, I didn't notice this !GP_IDLE... Please use GP_PASSED, this is what this actually means. And note the wait_event(GP_PASSED) in rcu_sync_enter(). Otherwise Reviewed-by: Oleg Nesterov