Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751971AbZCFGOz (ORCPT ); Fri, 6 Mar 2009 01:14:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751029AbZCFGOp (ORCPT ); Fri, 6 Mar 2009 01:14:45 -0500 Received: from e28smtp07.in.ibm.com ([59.145.155.7]:34798 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750729AbZCFGOo (ORCPT ); Fri, 6 Mar 2009 01:14:44 -0500 Date: Fri, 6 Mar 2009 11:44:38 +0530 From: Arun R Bharadwaj To: Oleg Nesterov Cc: linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org, a.p.zijlstra@chello.nl, ego@in.ibm.com, tglx@linutronix.de, mingo@elte.hu, andi@firstfloor.org, venkatesh.pallipadi@intel.com, vatsa@linux.vnet.ibm.com, arjan@infradead.org, svaidy@linux.vnet.ibm.com Subject: Re: [v2 PATCH 1/4] timers: framework to identify pinned timers. Message-ID: <20090306061438.GB9190@linux.vnet.ibm.com> Reply-To: arun@linux.vnet.ibm.com References: <20090304121249.GA9855@linux.vnet.ibm.com> <20090304121456.GB9855@linux.vnet.ibm.com> <20090305165340.GA6984@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090305165340.GA6984@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1249 Lines: 40 * Oleg Nesterov [2009-03-05 17:53:40]: > On 03/04, Arun R Bharadwaj wrote: > > > > +static inline unsigned long tbase_get_flag_bits(struct timer_list *timer) > > +{ > > + return tbase_get_deferrable(timer->base) | > > + tbase_get_pinned(timer->base); > > +} > > I'd say this looks a bit strange. Hopefully compiler can optimize this code > to return (unsigned long)base & (TBASE_DEFERRABLE_FLAG | TBASE_PINNED_FLAG). > Yes, it does. > > @@ -736,6 +759,7 @@ void add_timer_on(struct timer_list *tim > > struct tvec_base *base = per_cpu(tvec_bases, cpu); > > unsigned long flags; > > > > + timer_set_pinned(timer); > > But we never clear TBASE_PINNED_FLAG? > > If we use mod_timer() next time, the timer remains "pinned". I do not say > this is really wrong, but a bit strange imho. > > Oleg. > The pinned timer would expect to continue firing on the same CPU although it does a mod_timer() the next time, right? Thats why I have not cleared the TBASE_PINNED_FLAG. --arun -- 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/