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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 81EA3C433E0 for ; Wed, 10 Mar 2021 15:24:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4356864F60 for ; Wed, 10 Mar 2021 15:24:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231187AbhCJPYB (ORCPT ); Wed, 10 Mar 2021 10:24:01 -0500 Received: from mga02.intel.com ([134.134.136.20]:38467 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229602AbhCJPX7 (ORCPT ); Wed, 10 Mar 2021 10:23:59 -0500 IronPort-SDR: mN30GvvSgQzJSA3piu5p8bVklGGQyXi3d7x6GOOqqefia3Bnz5C1qvXbPTWrYrhVG5HewSjn7d 7R7PC53VTaCw== X-IronPort-AV: E=McAfee;i="6000,8403,9919"; a="175591770" X-IronPort-AV: E=Sophos;i="5.81,237,1610438400"; d="scan'208";a="175591770" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Mar 2021 07:23:58 -0800 IronPort-SDR: bRtDhYMHwW7QEbjiH14ChdldRcRD9gXCKABb3tIBs/ZeT/tUlV4taXTRkh4SKx2aJwNXe3dYo4 s6KbyvjZI2ng== X-IronPort-AV: E=Sophos;i="5.81,237,1610438400"; d="scan'208";a="437963249" Received: from tassilo.jf.intel.com ([10.54.74.11]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Mar 2021 07:23:57 -0800 From: Andi Kleen To: peterz@infradead.org Cc: linux-kernel@vger.kernel.org, Andi Kleen , jmattson@google.com Subject: [PATCH] perf/x86/kvm: Fix inverted pebs_no_isolation check Date: Wed, 10 Mar 2021 07:23:33 -0800 Message-Id: <20210310152333.1291338-1-ak@linux.intel.com> X-Mailer: git-send-email 2.25.4 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The pebs_no_isolation optimization check is inverted. We want to disable PEBS isolation when the microcode is at least the revision in the table, not for older microcode. So remove the extra !. It meant that the new microcodes did unnecessary work, and the old microcodes could crash the PEBS. Presumably most people already running with newer microcodes, so that functional impact is small. But it should speed up the newer systems by the 2-4% claimed in the original patch. Cc: jmattson@google.com Fixes: 9b545c04abd4 ("perf/x86/kvm: Avoid unnecessary work ...") Signed-off-by: Andi Kleen --- arch/x86/events/intel/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 5bac48d5c18e..d74deadd3a6d 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -4532,7 +4532,7 @@ static const struct x86_cpu_desc isolation_ucodes[] = { static void intel_check_pebs_isolation(void) { - x86_pmu.pebs_no_isolation = !x86_cpu_has_min_microcode_rev(isolation_ucodes); + x86_pmu.pebs_no_isolation = x86_cpu_has_min_microcode_rev(isolation_ucodes); } static __init void intel_pebs_isolation_quirk(void) -- 2.25.4