Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759571AbZCCAjm (ORCPT ); Mon, 2 Mar 2009 19:39:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753955AbZCCAjd (ORCPT ); Mon, 2 Mar 2009 19:39:33 -0500 Received: from tomts10-srv.bellnexxia.net ([209.226.175.54]:63795 "EHLO tomts10-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751183AbZCCAjc (ORCPT ); Mon, 2 Mar 2009 19:39:32 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AhwFAA4KrElMQW1W/2dsb2JhbACBWdNEhAYG Date: Mon, 2 Mar 2009 19:39:28 -0500 From: Mathieu Desnoyers To: Ingo Molnar Cc: Peter Zijlstra , Masami Hiramatsu , Andrew Morton , Nick Piggin , Steven Rostedt , Andi Kleen , linux-kernel@vger.kernel.org, Thomas Gleixner , Peter Zijlstra , Frederic Weisbecker , Linus Torvalds , Arjan van de Ven , Rusty Russell , "H. Peter Anvin" , Steven Rostedt Subject: Re: [PATCH] Text Edit Lock - Architecture Independent Code Message-ID: <20090303003928.GA6106@Krystal> References: <49AC10E9.1090102@redhat.com> <20090302171914.GB21735@Krystal> <49AC5A87.7000604@redhat.com> <20090302222254.GA31962@elte.hu> <49AC63FA.70801@redhat.com> <20090302230915.GA11626@elte.hu> <49AC6DEA.2050304@redhat.com> <20090302234910.GA17956@elte.hu> <20090303000054.GC3906@Krystal> <20090303003237.GA30221@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20090303003237.GA30221@elte.hu> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 19:37:53 up 2 days, 21:04, 3 users, load average: 0.49, 0.65, 0.67 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: 1347 Lines: 46 * Ingo Molnar (mingo@elte.hu) wrote: > > * Mathieu Desnoyers wrote: > > > +/* > > + * Take and release the kernel text modification lock, used for code patching. > > + * Users of this lock can sleep. > > + */ > > +extern void kernel_text_lock(void); > > +extern void kernel_text_unlock(void); > > Locking APIs with hidden semantics are very ugly. Remember > lock_kernel()? > > > +/* > > + * mutex protecting text section modification (dynamic code patching). > > + * some users need to sleep (allocating memory...) while they hold this lock. > > + */ > > +static DEFINE_MUTEX(text_mutex); > > Please update those sites to do an explicit: > > mutex_lock(&text_mutex); > > instead. > > That way we save a function call, and we'll also see exactly > what type of lock is being taken, etc. > OK. However we'll have to export the text_mutex symbol and use it in various locations. As long as we are fine with that, I'll provide an updated patch. Mathieu > Ingo -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- 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/