From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932350Ab1KGQCQ (ORCPT ); Mon, 7 Nov 2011 11:02:16 -0500 Received: from merlin.infradead.org ([205.233.59.134]:53302 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752546Ab1KGQCO convert rfc822-to-8bit (ORCPT ); Mon, 7 Nov 2011 11:02:14 -0500 Subject: Re: [PATCHv2 6/9] perf: expose perf capability to other modules. From: Peter Zijlstra To: Gleb Natapov Cc: kvm@vger.kernel.org, avi@redhat.com, mtosatti@redhat.com, linux-kernel@vger.kernel.org, mingo@elte.hu, acme@ghostprotocols.net Date: Mon, 07 Nov 2011 17:01:11 +0100 In-Reply-To: <20111107155336.GI8670@redhat.com> References: <1320323618-10375-1-git-send-email-gleb@redhat.com> <1320323618-10375-7-git-send-email-gleb@redhat.com> <1320674870.18053.37.camel@twins> <20111107155336.GI8670@redhat.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.0.3- Message-ID: <1320681671.17809.5.camel@twins> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-11-07 at 17:53 +0200, Gleb Natapov wrote: > I removed branch-miss-retired here because for perf user it exists. Perf > approximates it by other event but perf user shouldn't know that. A > guest is not always runs with exactly same cpu model number as a host, > so if we will not drop the bit here if guest will see cpu model other > than the one that has this quirk it will not be able to use the event. Right, so what model number do you expose? Anyway I don't really mind masking the thing as long as we grow an ebx iteration, > BTW why perf does not check event mask to see if architectural event is > available before programming it? No idea why not.. just one of those things nobody noticed/got around to doing or so.