Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756526Ab3ICPl3 (ORCPT ); Tue, 3 Sep 2013 11:41:29 -0400 Received: from mail-vc0-f182.google.com ([209.85.220.182]:43924 "EHLO mail-vc0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754304Ab3ICPl1 (ORCPT ); Tue, 3 Sep 2013 11:41:27 -0400 MIME-Version: 1.0 In-Reply-To: <20130903101522.GA22369@gmail.com> References: <20130901212355.GU13318@ZenIV.linux.org.uk> <20130901233005.GX13318@ZenIV.linux.org.uk> <20130902070538.GA31639@gmail.com> <20130903101522.GA22369@gmail.com> Date: Tue, 3 Sep 2013 08:41:26 -0700 X-Google-Sender-Auth: VMf3bl3qp-QhUnONEmeUbglAscg Message-ID: Subject: Re: [PATCH v7 1/4] spinlock: A new lockref structure for lockless update of refcount From: Linus Torvalds To: Ingo Molnar Cc: Al Viro , Sedat Dilek , Waiman Long , Benjamin Herrenschmidt , Jeff Layton , Miklos Szeredi , Ingo Molnar , Thomas Gleixner , linux-fsdevel , Linux Kernel Mailing List , Peter Zijlstra , Steven Rostedt , Andi Kleen , "Chandramouleeswaran, Aswin" , "Norton, Scott J" , Peter Zijlstra , Arnaldo Carvalho de Melo Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 708 Lines: 16 On Tue, Sep 3, 2013 at 3:15 AM, Ingo Molnar wrote: > > One more thing to try would be a regular '-e cycles' non-PEBS run and see > whether there's still largish overhead visible around that instruction. I've done that, and it matches the PEBS runs, except obviously with the instruction skew (so then depending on run it's 95% the instruction after the xadd). So the PEBS profiles are entirely consistent with other data. Linus -- 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/