Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754710AbXH1HND (ORCPT ); Tue, 28 Aug 2007 03:13:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751071AbXH1HMw (ORCPT ); Tue, 28 Aug 2007 03:12:52 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:43375 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751395AbXH1HMv (ORCPT ); Tue, 28 Aug 2007 03:12:51 -0400 Subject: Re: [PATCH] SLUB use cmpxchg_local From: Peter Zijlstra To: Christoph Lameter Cc: Mathieu Desnoyers , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, mingo@redhat.com In-Reply-To: References: <20070820201519.512791382@polymtl.ca> <20070820201822.597720007@polymtl.ca> <20070820204126.GA22507@Krystal> <20070820212922.GA27011@Krystal> <20070820215413.GA28452@Krystal> <20070821173849.GA8360@Krystal> <1188197539.6114.426.camel@twins> Content-Type: text/plain Date: Tue, 28 Aug 2007 09:12:39 +0200 Message-Id: <1188285159.6112.4.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 853 Lines: 20 On Mon, 2007-08-27 at 15:15 -0700, Christoph Lameter wrote: > Hmmmm. One wild idea would be to use a priority futex for the slab lock? > That would make the slow paths interrupt safe without requiring interrupt > disable? Does a futex fit into the page struct? Very much puzzled at what you propose. in-kernel we use rt_mutex (has PI) or mutex, futexes are user-space. (on -rt spinlock_t == mutex == rt_mutex) Neither disable interrupts since they are sleeping locks. That said, on -rt we do not need to disable interrupts in the allocators because its a bug to call an allocator from raw irq context. - 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/