Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932437Ab1EFRJp (ORCPT ); Fri, 6 May 2011 13:09:45 -0400 Received: from mail-wy0-f174.google.com ([74.125.82.174]:55698 "EHLO mail-wy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932412Ab1EFRJn (ORCPT ); Fri, 6 May 2011 13:09:43 -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=o369ZElF0AYwJyV1k5UXWUwZrpJ6AeMu0c9NE8UkuuPoQ3APhdqlh2hNCrTAxxzXYR G4eBFcRgY+fZ6lFJszDtOPZWbchh4LKw+sCHf4iEp+P8oezf/UohljSaEGAlOtWKeJlq 7qJPXmrE1a1vg5zgslbP18JWvpNqZM8vL61BY= Subject: Re: [RFC] time: xtime_lock is held too long From: Eric Dumazet To: Andi Kleen Cc: Thomas Gleixner , john stultz , lkml , Paul Mackerras , "Paul E. McKenney" , Anton Blanchard , Ingo Molnar In-Reply-To: <20110506165913.GF11636@one.firstfloor.org> References: <1304564090.2943.36.camel@work-vm> <1304574244.32152.666.camel@edumazet-laptop> <1304576495.2943.40.camel@work-vm> <1304604284.3032.78.camel@edumazet-laptop> <1304608095.3032.95.camel@edumazet-laptop> <20110505210118.GI2925@one.firstfloor.org> <20110506165913.GF11636@one.firstfloor.org> Content-Type: text/plain; charset="UTF-8" Date: Fri, 06 May 2011 19:09:38 +0200 Message-ID: <1304701778.3066.165.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: 944 Lines: 26 Le vendredi 06 mai 2011 à 18:59 +0200, Andi Kleen a écrit : > On Fri, May 06, 2011 at 12:18:27PM +0200, Thomas Gleixner wrote: > If that code path shows up in profiling. Only the timer interrupt > did so far. > > > That's the completely wrong aproach, really. If stuff takes too long, > > then we need to tackle it at the root of the problem and not solve it > > by sprinkling magic prefetches all over the place. > > If you have a better way to make it faster please share it. > Unless I am very mistaken, it cannot explain my original report of up to 24.000 instructions waiting in ktime_get() BTW, how many consecutive prefetch() a cpu can 'store/execute' before throwing away hints ? -- 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/