From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (146.0.238.70:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 08 Feb 2019 09:02:26 -0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by Galois.linutronix.de with esmtps (TLS1.2:RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1gs23E-0005RY-Fu for speck@linutronix.de; Fri, 08 Feb 2019 10:02:25 +0100 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 1gs23C-0004WH-NV for speck@linutronix.de; Fri, 08 Feb 2019 09:02:23 +0000 Date: Fri, 8 Feb 2019 10:02:21 +0100 From: Peter Zijlstra Subject: [MODERATED] Re: [PATCH v3 3/6] PERFv3 Message-ID: <20190208090221.GL32477@hirez.programming.kicks-ass.net> References: MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: speck@linutronix.de List-ID: On Thu, Feb 07, 2019 at 03:41:05PM -0800, speck for Andi Kleen wrote: > From: Andi Kleen > Subject: x86/pmu/intel: Add perf event attribute to control RTM > > Add a "force_rtm_abort" attribute per perf event attribute > to allow user programs to opt in to use counter 3 and disable > TSX while the perf event is active. > > Also add a "allow_rtm" attribute to allow programs to > make sure TSX is enabled during the measurement (e.g. > if they want to measure TSX itself) > > This allows non root programs to override the defaults > for their needs. > > This is also needed for correct semantics in guests, > so that the KVM PMU can set the correct default > for its guests. > > We use config2 bits 0/1 in the core PMU for these > interfaces. Again; why? This isn't needed _at_all_.