From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B135C43441 for ; Thu, 29 Nov 2018 15:35:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C41492082F for ; Thu, 29 Nov 2018 15:35:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="WBTUN4tr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C41492082F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728590AbeK3ClU (ORCPT ); Thu, 29 Nov 2018 21:41:20 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:52184 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728233AbeK3ClU (ORCPT ); Thu, 29 Nov 2018 21:41:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=e/44OweujBTvsgHnwuyRm5zM9pAVKO0ArllTpHzSSnY=; b=WBTUN4tr+UwG/Uu1TdcA6EXtB 1SexAHzTOo6IHXwRoNpktwGRotJJPQ+nktW7ZZ3ZlWlPU2CxGgWFw0jglyB69v8MKeKGbZAUIWDr7 B9Ltg1JwIKAgXQjTXfifR6nPTKOiK91cktOzbNfhnEMpbdzMBac2cek8fe170kkhcceRi0IKJzrhV 4uJHWJ5WWeDjLBQX/MuthriwtUSClk/mewyYK3shH02aWAgLRCc6TCKJR/fmFppzTw0wSwzGadjak 2cZo6fB3VhH0CicQct4Yq2rq0CiDzkPBzHYWIjgPDmwrGsmclkupBkKncdjRaZ9zWa/6aXSzfWeDv R3c5ykUPg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1gSOLf-0000Cf-PZ; Thu, 29 Nov 2018 15:35:27 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 2CE7F2029FD58; Thu, 29 Nov 2018 16:35:26 +0100 (CET) Date: Thu, 29 Nov 2018 16:35:26 +0100 From: Peter Zijlstra To: Andi Kleen Cc: Kyle Huey , Kan Liang , Ingo Molnar , Robert O'Callahan , Alexander Shishkin , Arnaldo Carvalho de Melo , Jiri Olsa , Linus Torvalds , Stephane Eranian , Thomas Gleixner , Vince Weaver , acme@kernel.org, open list Subject: Re: [REGRESSION] x86, perf: counter freezing breaks rr Message-ID: <20181129153526.GR2131@hirez.programming.kicks-ass.net> References: <20181120194129.GC13936@tassilo.jf.intel.com> <20181120201144.GD13936@tassilo.jf.intel.com> <20181120221642.GE2131@hirez.programming.kicks-ass.net> <20181120222549.GA2149@hirez.programming.kicks-ass.net> <20181120223854.GH13936@tassilo.jf.intel.com> <20181121081420.GF2131@hirez.programming.kicks-ass.net> <20181127233615.GY13936@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181127233615.GY13936@tassilo.jf.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 27, 2018 at 03:36:15PM -0800, Andi Kleen wrote: > > It does seem that FREEZE_PERFMON_ON_PMI (misnamed as it is) is of > > rather limited use (or even negative, in our case) to a counter that's > > already restricted to ring 3. > > It's much faster. The PMI cost goes down dramatically. faster doesn't mean much when its broken.