Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933981Ab1D2WQ4 (ORCPT ); Fri, 29 Apr 2011 18:16:56 -0400 Received: from mail.skyhub.de ([78.46.96.112]:46501 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933950Ab1D2WQr (ORCPT ); Fri, 29 Apr 2011 18:16:47 -0400 Date: Sat, 30 Apr 2011 00:16:42 +0200 From: Borislav Petkov To: Vince Weaver Cc: Ingo Molnar , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Stephane Eranian , Andi Kleen , Thomas Gleixner Subject: Re: re-enable Nehalem raw Offcore-Events support Message-ID: <20110429221642.GA10751@liondog.tnic> Mail-Followup-To: Borislav Petkov , Vince Weaver , Ingo Molnar , torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Stephane Eranian , Andi Kleen , Thomas Gleixner References: <20110429164227.GA25491@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20110429164227.GA25491@elte.hu> 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: 2212 Lines: 46 On Fri, Apr 29, 2011 at 06:42:27PM +0200, Ingo Molnar wrote: [..] > Basically without proper generalization people get sloppy and go the fast path > and export very low level, opaque, unstructured PMU interfaces to user-space > and repeat the Oprofile and perfmon tooling mistakes again and again. > > "Thinking is hard, lets go shopping^W exporting raw ABIs." > > So the perf events policy has always been that while we tolerate raw events > (there's nothing bad with offering them once generic events have crystallized > out), we only accept them if the *useful* events are first abstracted and > generalized out. > > We put structure, proper abstractions and easy tooling *ahead* of the interests > of a small group of people who'd rather prefer a lowlevel, opaque hardware > channel so that they do not have to *think* about generalization and also > perhaps so they do not have to share their selection of events and analysis > methods with others ... Yep, absolutely. Excuse my french but even kernel developers who can understand perf code don't need to know f*cking magical hex constants in order to trace a little. And yes, we talk about perf and say how cool it is but users want to see more examples like on http://perf.wiki.kernel.org - they want to get to use it first _and_ _then_ maybe look at code/more involved scenarios. Other kernel developers don't give a rat's ass about the possibility for shooting themselves in the foot - they want to use this thing without reading code and CPU documentation for a day first. And I believe I speak for the majority when I say so. We're always bitching about Linux usability and now when it comes down to yet another case where this can be done right for a change, and perf people are trying to do something productive, you come waving hands loudly at Linus with revert requests instead of helping. This is as productive as trying to shoot yourself in the foot. -- Regards/Gruss, Boris. -- 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/