Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759887Ab1D0TuN (ORCPT ); Wed, 27 Apr 2011 15:50:13 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:48944 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756710Ab1D0TuK (ORCPT ); Wed, 27 Apr 2011 15:50:10 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=BrAxTVyvggHleaDkienBXGfW2NOPeLYemylp05ZfP/NBdwkFEbM1Sx1Vh5CP9F+yxA yuY9AsPJ9KK+i7GhgRoTB6w0sImmQQwY78/CjbHPYkMN0E9fs39vpDxAXnSmQ8wLfEuI UIEfKu1pnAIVrA+z022esHSx2YtXZMzlvEFs0= Date: Wed, 27 Apr 2011 21:50:07 +0200 From: Frederic Weisbecker To: "H. Peter Anvin" Cc: LKML , Ingo Molnar , Peter Zijlstra , Jason Wessel , Thomas Gleixner Subject: Re: [PATCH 3/6] x86: Allow the user not to build hw_breakpoints Message-ID: <20110427195004.GA3654@nowhere> References: <1303923602-2923-1-git-send-email-fweisbec@gmail.com> <1303923602-2923-4-git-send-email-fweisbec@gmail.com> <4DB854AA.6070101@zytor.com> <20110427182633.GB1753@nowhere> <008d59a3-bd23-4cb3-8a73-1640137e3ac4@email.android.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <008d59a3-bd23-4cb3-8a73-1640137e3ac4@email.android.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 823 Lines: 14 On Wed, Apr 27, 2011 at 11:54:17AM -0700, H. Peter Anvin wrote: > Why do you have to be able to disable breakpoints to disable perf? That seems seriously backwards, especially since we had breakpoints long before perf... That started when we implemented breakpoints as counters. Then we realized that ptrace had its own scheduling that was somehow duplicating what perf was doing. So we have finally unified that under perf. The good point is that archs don't need to care much about ptrace breakpoints tracking, just the interface. But yeah the bad point is that dependency. -- 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/