From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756306AbZBTDG3 (ORCPT ); Thu, 19 Feb 2009 22:06:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752116AbZBTDGU (ORCPT ); Thu, 19 Feb 2009 22:06:20 -0500 Received: from hera.kernel.org ([140.211.167.34]:58441 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751676AbZBTDGU (ORCPT ); Thu, 19 Feb 2009 22:06:20 -0500 Message-ID: <499E1DCF.7090005@kernel.org> Date: Fri, 20 Feb 2009 12:04:47 +0900 From: Tejun Heo User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Nick Piggin CC: rusty@rustcorp.com.au, tglx@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, jeremy@goop.org, cpw@sgi.com, mingo@elte.hu Subject: Re: [PATCH 09/10] percpu: implement new dynamic percpu allocator References: <1234958676-27618-1-git-send-email-tj@kernel.org> <1234958676-27618-10-git-send-email-tj@kernel.org> <200902192336.02800.nickpiggin@yahoo.com.au> In-Reply-To: <200902192336.02800.nickpiggin@yahoo.com.au> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 20 Feb 2009 03:04:31 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Nick. Nick Piggin wrote: > On Wednesday 18 February 2009 23:04:35 Tejun Heo wrote: >> Impact: new scalable dynamic percpu allocator which allows dynamic >> percpu areas to be accessed the same way as static ones >> >> Implement scalable dynamic percpu allocator which can be used for both >> static and dynamic percpu areas. This will allow static and dynamic >> areas to share faster direct access methods. This feature is optional >> and enabled only when CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is defined by >> arch. Please read comment on top of mm/percpu.c for details. > > Seems pretty nice. Wishlist: would be cool to have per-cpu virtual > memory mappings and do CPU-local percpu access via a single pointer. > Of course there would need to be some machinery and maybe a new API > to be more careful about accessing remote percpu data (that access > could perhaps just be slower and go via the linear mapping). Yeah, that's what's scheduled next. Direct percpu accessors and probably consolidation of local_t into percpu accessors. Once dust around the allocator itself settles down, I'll work on those. Thanks. -- tejun