Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161197AbWBTXe7 (ORCPT ); Mon, 20 Feb 2006 18:34:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161200AbWBTXe7 (ORCPT ); Mon, 20 Feb 2006 18:34:59 -0500 Received: from smtp.osdl.org ([65.172.181.4]:11652 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1161197AbWBTXe6 (ORCPT ); Mon, 20 Feb 2006 18:34:58 -0500 Date: Mon, 20 Feb 2006 15:33:20 -0800 From: Andrew Morton To: Ravikiran G Thirumalai Cc: linux-kernel@vger.kernel.org, shai@scalex86.org Subject: Re: [patch] Cache align futex hash buckets Message-Id: <20060220153320.793b6a7d.akpm@osdl.org> In-Reply-To: <20060220233242.GC3594@localhost.localdomain> References: <20060220233242.GC3594@localhost.localdomain> X-Mailer: Sylpheed version 1.0.4 (GTK+ 1.2.10; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1281 Lines: 31 Ravikiran G Thirumalai wrote: > > Following change places each element of the futex_queues hashtable on a > different cacheline. Spinlocks of adjacent hash buckets lie on the same > cacheline otherwise. > > Signed-off-by: Ravikiran Thirumalai > Signed-off-by: Shai Fultheim > > Index: linux-2.6.16-rc2/kernel/futex.c > =================================================================== > --- linux-2.6.16-rc2.orig/kernel/futex.c 2006-02-07 23:14:04.000000000 -0800 > +++ linux-2.6.16-rc2/kernel/futex.c 2006-02-09 14:04:22.000000000 -0800 > @@ -100,9 +100,10 @@ struct futex_q { > struct futex_hash_bucket { > spinlock_t lock; > struct list_head chain; > -}; > +} ____cacheline_internodealigned_in_smp; > > -static struct futex_hash_bucket futex_queues[1< +static struct futex_hash_bucket futex_queues[1< + __cacheline_aligned_in_smp; > How much memory does that thing end up consuming? - 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/