Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934299Ab1CXUvl (ORCPT ); Thu, 24 Mar 2011 16:51:41 -0400 Received: from mail-bw0-f46.google.com ([209.85.214.46]:61539 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934262Ab1CXUvj (ORCPT ); Thu, 24 Mar 2011 16:51:39 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=vyarI+EJn5wNCVQqgNcGVHh5UKA1MA3IT+XPAr7Z2OkcU3NCoxra+4X3bYvem5zmSP dVgwYOA5B4lNfrRygJr9L8OhbkmPhsOr4iHFhCkJrkquKVwm4w7s3J7b2Ex76xA1NLcj xhXmk5kfwZG3dCIUwY3TAUPJY6RAKqN1Yh1sE= Subject: Re: [PATCH RFC] x86: avoid atomic operation in test_and_set_bit_lock if possible From: Eric Dumazet To: Ingo Molnar Cc: Jack Steiner , Jan Beulich , Borislav Petkov , Peter Zijlstra , Nick Piggin , "x86@kernel.org" , Thomas Gleixner , Andrew Morton , Linus Torvalds , Ingo Molnar , tee@sgi.com, Nikanth Karthikesan , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" In-Reply-To: <20110324200010.GB7957@elte.hu> References: <201103241026.01624.knikanth@suse.de> <20110324085647.GI30812@elte.hu> <20110324145221.GC31194@aftab> <4D8B83DA02000078000381DE@vpn.id2.novell.com> <20110324173020.GA26761@sgi.com> <20110324200010.GB7957@elte.hu> Content-Type: text/plain; charset="UTF-8" Date: Thu, 24 Mar 2011 21:48:02 +0100 Message-ID: <1300999682.2714.23.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1041 Lines: 36 Le jeudi 24 mars 2011 à 21:00 +0100, Ingo Molnar a écrit : > One good way to see cache bounces is to run a misses/accesses ratio profile: > > perf top -e cache-misses -e cache-references --count-filter 10 > Oh well , something must be broken... "perf top" is working here, but if I use any "-e ...." argument, it fails : # perf top -e cache-misses Error: sys_perf_event_open() syscall returned with 2 (No such file or directory). /bin/dmesg may provide additional information. Fatal: No CONFIG_PERF_EVENTS=y kernel support configured? # grep PERF_EVENTS .config CONFIG_HAVE_PERF_EVENTS=y CONFIG_PERF_EVENTS=y CONFIG_HAVE_PERF_EVENTS_NMI=y Nothing in dmesg... uname -a Linux ed001 2.6.38-08165-g2712750-dirty #517 SMP Thu Mar 24 21:31:00 CET 2011 i686 i686 i386 GNU/Linux -- 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/