From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 373066B009E for ; Mon, 25 Jan 2010 14:01:20 -0500 (EST) Date: Mon, 25 Jan 2010 20:00:52 +0100 From: Andrea Arcangeli Subject: Re: [PATCH] - Fix unmap_vma() bug related to mmu_notifiers Message-ID: <20100125190052.GF5756@random.random> References: <20100125174556.GA23003@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100125174556.GA23003@sgi.com> Sender: owner-linux-mm@kvack.org To: Jack Steiner Cc: mingo@elte.hu, tglx@linutronix.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Mon, Jan 25, 2010 at 11:45:56AM -0600, Jack Steiner wrote: > unmap_vmas() can fail to correctly flush the TLB if a > callout to mmu_notifier_invalidate_range_start() sleeps. Not sure I understand: the callbacks invoked by mmu_notifier_invalidate_range_start can't sleep, or rcu locking inside mmu notifier will break too (first thing that should be replaced with srcu if they were allowed to sleep). In short there's no schedule that could be added because of those callbacks so if this code isn't ok and schedules and screw on the mmu_gather tlb it's probably not mmu notifier related. -- 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