From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f42.google.com (mail-pa0-f42.google.com [209.85.220.42]) by kanga.kvack.org (Postfix) with ESMTP id 5DF6C6B0038 for ; Thu, 15 Jan 2015 23:07:27 -0500 (EST) Received: by mail-pa0-f42.google.com with SMTP id et14so21779664pad.1 for ; Thu, 15 Jan 2015 20:07:27 -0800 (PST) Received: from cdptpa-oedge-vip.email.rr.com (cdptpa-outbound-snat.email.rr.com. [107.14.166.229]) by mx.google.com with ESMTP id c4si4087434pas.96.2015.01.15.20.07.25 for ; Thu, 15 Jan 2015 20:07:26 -0800 (PST) Date: Thu, 15 Jan 2015 23:07:49 -0500 From: Steven Rostedt Subject: Re: [PATCH v2 1/2] mm/slub: optimize alloc/free fastpath by removing preemption on/off Message-ID: <20150115230749.5d73ad49@grimm.local.home> In-Reply-To: References: <1421307633-24045-1-git-send-email-iamjoonsoo.kim@lge.com> <20150115171634.685237a4.akpm@linux-foundation.org> <20150115203045.00e9fb73@grimm.local.home> <20150115225130.00c0c99a@grimm.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Andrew Morton , Joonsoo Kim , Pekka Enberg , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Jesper Dangaard Brouer , Thomas Gleixner , Peter Zijlstra On Thu, 15 Jan 2015 21:57:58 -0600 (CST) Christoph Lameter wrote: > > I get: > > > > mov %gs:0x18(%rax),%rdx > > > > Looks to me that %gs is used. > > %gs is used as a segment prefix. That does not add significant cycles. > Retrieving the content of %gs and loading it into another register > would be expensive in terms of cpu cycles. OK, maybe that's what I saw in my previous benchmarks. Again, that was a while ago. -- Steve -- 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