From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 13 May 2007 01:42:57 +0400 From: Oleg Nesterov Subject: Re: [PATCH 1/2] scalable rw_mutex Message-ID: <20070512214257.GA389@tv-sign.ru> References: <20070511131541.992688403@chello.nl> <20070511132321.895740140@chello.nl> <20070511093108.495feb70.akpm@linux-foundation.org> <20070511110522.ed459635.akpm@linux-foundation.org> <20070512181254.GA331@tv-sign.ru> <20070512192130.GA8833@one.firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070512192130.GA8833@one.firstfloor.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andi Kleen Cc: Andrew Morton , Christoph Lameter , Peter Zijlstra , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ingo Molnar , Thomas Gleixner , Nick Piggin List-ID: On 05/12, Andi Kleen wrote: > > > This also allows us to de-uglify workqueue.c a little bit, it uses > > a home-grown cpu_populated_map. > > It might be obsolete iff more and more architecture don't use NR_CPUS filled > possible_map anymore (haven't checked them all to know if it's true or not) > > If not there are a couple of more optimizations that can be done, e.g. > in networking by converting more code to hotplug notifier. As for workqueue.c, it is not an optimization. It is a documentation. For example, if CPU-hotplug use freezer, we can just do s/cpu_populated_map/cpu_online_map/ workqueue.c has a hotplug notifier, but we can't migrate work_structs currently in a race-free manner. So I vote for your patch in any case. Oleg. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org