From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f181.google.com (mail-ig0-f181.google.com [209.85.213.181]) by kanga.kvack.org (Postfix) with ESMTP id 869D46B0032 for ; Wed, 17 Dec 2014 14:44:25 -0500 (EST) Received: by mail-ig0-f181.google.com with SMTP id l13so10259256iga.14 for ; Wed, 17 Dec 2014 11:44:25 -0800 (PST) Received: from resqmta-po-04v.sys.comcast.net (resqmta-po-04v.sys.comcast.net. [2001:558:fe16:19:96:114:154:163]) by mx.google.com with ESMTPS id q15si4153670ics.106.2014.12.17.11.44.23 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Wed, 17 Dec 2014 11:44:24 -0800 (PST) Date: Wed, 17 Dec 2014 13:44:21 -0600 (CST) From: Christoph Lameter Subject: Re: [PATCH 0/7] slub: Fastpath optimization (especially for RT) V1 In-Reply-To: Message-ID: References: <20141210163017.092096069@linux.com> <20141215075933.GD4898@js1304-P5Q-DELUXE> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Joonsoo Kim Cc: Joonsoo Kim , akpm@linuxfoundation.org, Steven Rostedt , LKML , Thomas Gleixner , Linux Memory Management List , Pekka Enberg , Jesper Dangaard Brouer On Wed, 17 Dec 2014, Christoph Lameter wrote: > On Wed, 17 Dec 2014, Joonsoo Kim wrote: > > > + do { > > + tid = this_cpu_read(s->cpu_slab->tid); > > + c = this_cpu_ptr(s->cpu_slab); > > + } while (IS_ENABLED(CONFIG_PREEMPT) && unlikely(tid != c->tid)); Here is another one without debugging: 0xffffffff811d23bb <+59>: mov %gs:0x8(%r9),%rdx tid(rdx) = this_cpu_read() 0xffffffff811d23c0 <+64>: mov %r9,%r8 0xffffffff811d23c3 <+67>: add %gs:0x7ee37d9d(%rip),%r8 c (r8) = 0xffffffff811d23cb <+75>: cmp 0x8(%r8),%rdx c->tid == tid 0xffffffff811d23cf <+79>: jne 0xffffffff811d23bb Actually that looks ok. -- 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