Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756005AbbEFBtq (ORCPT ); Tue, 5 May 2015 21:49:46 -0400 Received: from mail-wi0-f179.google.com ([209.85.212.179]:37173 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755969AbbEFBto (ORCPT ); Tue, 5 May 2015 21:49:44 -0400 Message-ID: <1430876985.3169.4.camel@gmail.com> Subject: Re: question about RCU dynticks_nesting From: Mike Galbraith To: paulmck@linux.vnet.ibm.com Cc: Rik van Riel , Paolo Bonzini , Ingo Molnar , Andy Lutomirski , "linux-kernel@vger.kernel.org" , X86 ML , williams@redhat.com, Andrew Lutomirski , fweisbec@redhat.com, Peter Zijlstra , Heiko Carstens , Thomas Gleixner , Ingo Molnar , Linus Torvalds Date: Wed, 06 May 2015 03:49:45 +0200 In-Reply-To: <20150505055413.GJ5381@linux.vnet.ibm.com> References: <20150502052733.GA9983@gmail.com> <55473B47.6080600@redhat.com> <55479749.7070608@redhat.com> <20150504183906.GS5381@linux.vnet.ibm.com> <5547CAED.9010201@redhat.com> <20150504200232.GB5381@linux.vnet.ibm.com> <5547D2FE.9010806@redhat.com> <20150504203801.GG5381@linux.vnet.ibm.com> <5547DC3C.1000504@redhat.com> <20150505055413.GJ5381@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.11 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 518 Lines: 15 On Mon, 2015-05-04 at 22:54 -0700, Paul E. McKenney wrote: > You have RCU_FAST_NO_HZ=y, correct? Could you please try measuring with > RCU_FAST_NO_HZ=n? FWIW, the syscall numbers I posted were RCU_FAST_NO_HZ=n. (I didn't profile to see where costs lie though) -Mike -- 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/