Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751733AbWB0TJr (ORCPT ); Mon, 27 Feb 2006 14:09:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751734AbWB0TJq (ORCPT ); Mon, 27 Feb 2006 14:09:46 -0500 Received: from e33.co.us.ibm.com ([32.97.110.151]:7891 "EHLO e33.co.us.ibm.com") by vger.kernel.org with ESMTP id S1751723AbWB0TJq (ORCPT ); Mon, 27 Feb 2006 14:09:46 -0500 Subject: Re: [Lse-tech] Re: [Patch 2/7] Add sysctl for schedstats From: Chandra Seetharaman Reply-To: sekharan@us.ibm.com To: Nick Piggin Cc: nagar@watson.ibm.com, linux-kernel , lse-tech In-Reply-To: <4402C3BB.7010705@yahoo.com.au> References: <1141026996.5785.38.camel@elinux04.optonline.net> <1141027367.5785.42.camel@elinux04.optonline.net> <1141027923.5785.50.camel@elinux04.optonline.net> <4402C3BB.7010705@yahoo.com.au> Content-Type: text/plain Organization: IBM Date: Mon, 27 Feb 2006 11:09:42 -0800 Message-Id: <1141067382.4770.699.camel@linuxchandra> Mime-Version: 1.0 X-Mailer: Evolution 2.0.4 (2.0.4-7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1139 Lines: 34 On Mon, 2006-02-27 at 20:17 +1100, Nick Piggin wrote: > > #ifdef CONFIG_SCHEDSTATS > > + > > +int schedstats_sysctl = 0; /* schedstats turned off by default */ > > Should be read mostly. > > > +static DEFINE_PER_CPU(int, schedstats) = 0; > > + > > When the above is in the read mostly section, you won't need this at all. > > You don't intend to switch the sysctl with great frequency, do you? No, it is not expected to switch often. We originally coded it as __read_mostly, but thought the variable bouncing between CPUs would be costly. Is it cheaper with __read_mostly ? or it doesn't matter ? -- ---------------------------------------------------------------------- Chandra Seetharaman | Be careful what you choose.... - sekharan@us.ibm.com | .......you may get it. ---------------------------------------------------------------------- - 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/