Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759304AbZCXP0P (ORCPT ); Tue, 24 Mar 2009 11:26:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757050AbZCXPZ4 (ORCPT ); Tue, 24 Mar 2009 11:25:56 -0400 Received: from hera.kernel.org ([140.211.167.34]:45083 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755741AbZCXPZz (ORCPT ); Tue, 24 Mar 2009 11:25:55 -0400 Message-ID: <49C8FAC4.6060508@kernel.org> Date: Wed, 25 Mar 2009 00:22:44 +0900 From: Tejun Heo User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Martin Schwidefsky CC: mingo@elte.hu, rusty@rustcorp.com.au, tglx@linutronix.de, x86@kernel.org, linux-kernel@vger.kernel.org, hpa@zytor.com, Paul Mundt , rmk@arm.linux.org.uk, starvik@axis.com, ralf@linux-mips.org, davem@davemloft.net, cooloney@kernel.org, kyle@mcmartin.ca, matthew@wil.cx, grundler@parisc-linux.org, takata@linux-m32r.org, benh@kernel.crashing.org, rth@twiddle.net, ink@jurassic.park.msu.ru, heiko.carstens@de.ibm.com Subject: Re: [GIT RFC] percpu: use dynamic percpu allocator as the default percpu allocator References: <1236671631-9305-1-git-send-email-tj@kernel.org> <20090316190132.7965a49a@skybase> <49C300D8.5080204@kernel.org> In-Reply-To: <49C300D8.5080204@kernel.org> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Tue, 24 Mar 2009 15:22:55 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1487 Lines: 40 Tejun Heo wrote: > Hello, Martin. > > Sorry about the delay. > > Martin Schwidefsky wrote: >> We do have a problem with #2, the dynamic percpu patches currently >> breaks s390. But the nice thing is that we can now get rid of the GOTENT >> relocation for the percpu symbols. If the code is changed to use >> RELOC_HIDE for the SHIFT_PERCPU_PTR define, everything works just fine. >> Patch attached. Nice works guys. >> >> Subject: [PATCH] s390: percpu access. >> >> From: Martin Schwidefsky >> >> With the dynamic percpu allocator there is no need anymore to play >> tricks with the GOTENT relocation for the access to the percpu >> symbols. A simple RELOC_HIDE gets the job done. > > Hmm... I don't quite get it. The GOTENT was to work around large > offsets for modules, right? Can you please explain what changed by > the dynamic percpu allocator? > >> +#define SHIFT_PERCPU_PTR(var, offset) RELOC_HIDE(&per_cpu_var(var), (offset)) > > Hmm... @var already has per_cpu__ prefix when the above macro is > invoked, so doing per_cpu_var() on it again wouldn't work. If simple > RELOC_HIDE works, you should be able to simply drop the above > definition. The generic percpu.h will define it. Ping. -- tejun -- 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/