Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756637AbZA1VXu (ORCPT ); Wed, 28 Jan 2009 16:23:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751672AbZA1VXf (ORCPT ); Wed, 28 Jan 2009 16:23:35 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:39485 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751552AbZA1VXf (ORCPT ); Wed, 28 Jan 2009 16:23:35 -0500 Date: Wed, 28 Jan 2009 16:23:32 -0500 (EST) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Andrew Morton cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, mingo@elte.hu, tglx@linutronix.de, peterz@infradead.org, arjan@infradead.org, rusty@rustcorp.com.au, jens.axboe@oracle.com Subject: Re: Buggy IPI and MTRR code on low memory In-Reply-To: <20090128131327.417b01e1.akpm@linux-foundation.org> Message-ID: References: <20090128131202.21757da6.akpm@linux-foundation.org> <20090128131327.417b01e1.akpm@linux-foundation.org> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 962 Lines: 28 On Wed, 28 Jan 2009, Andrew Morton wrote: > On Wed, 28 Jan 2009 13:12:02 -0800 > Andrew Morton wrote: > > > Thought: do we need to do the kmalloc at all? Perhaps we can instead > > use a statically allocated per-cpu call_single_data local to > > kernel/smp.c? It would need a spinlock or something to protect it... > > (not a spinlock - get_cpu_var/put_cpu_var will suffice) Is that enough? The calling IPIs may process the data after smp_call_function is made. What happens if two smp_call_functions are executed one after the other? The second one may corrupt the data if the IPI function has not executed yet. We may still need that "RELEASE" flag for that case. -- Steve -- 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/