Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753834AbbBLCq4 (ORCPT ); Wed, 11 Feb 2015 21:46:56 -0500 Received: from resqmta-ch2-01v.sys.comcast.net ([69.252.207.33]:43440 "EHLO resqmta-ch2-01v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751781AbbBLCqz (ORCPT ); Wed, 11 Feb 2015 21:46:55 -0500 Date: Wed, 11 Feb 2015 20:46:53 -0600 (CST) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Jesper Dangaard Brouer cc: akpm@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, penberg@kernel.org, iamjoonsoo@lge.com Subject: Re: [PATCH 2/3] slub: Support for array operations In-Reply-To: <20150212131649.59b70f71@redhat.com> Message-ID: References: <20150210194804.288708936@linux.com> <20150210194811.902155759@linux.com> <20150211174817.44cc5562@redhat.com> <20150212104316.2d5c32ea@redhat.com> <20150212131649.59b70f71@redhat.com> 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: 1018 Lines: 23 On Thu, 12 Feb 2015, Jesper Dangaard Brouer wrote: > Measured on my laptop CPU i7-2620M CPU @ 2.70GHz: > > * 12.775 ns - "clean" spin_lock_unlock > * 21.099 ns - irqsave variant spinlock > * 22.808 ns - "manual" irqsave before spin_lock > * 14.618 ns - "manual" local_irq_disable + spin_lock > > Reproducible via my github repo: > https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/lib/time_bench_sample.c > > The clean spin_lock_unlock is 8.324 ns faster than irqsave variant. > The irqsave variant is actually faster than expected, as the measurement > of an isolated local_irq_save_restore were 13.256 ns. I am using spin_lock_irq() in the current version on my system. If the performance of that is a problem then please optimize that function. -- 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/