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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 A780BC677D4 for ; Mon, 8 Oct 2018 18:40:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 70C432087D for ; Mon, 8 Oct 2018 18:40:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ep2uHrl2" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 70C432087D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.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 S1729650AbeJIBxM (ORCPT ); Mon, 8 Oct 2018 21:53:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:40468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727315AbeJIBxL (ORCPT ); Mon, 8 Oct 2018 21:53:11 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BBBB3214C3; Mon, 8 Oct 2018 18:40:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539024007; bh=4Sq+qpIWduUW/Dcm6wdl+uwyRI8RUS8SyX+cuOdmiZo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ep2uHrl2MBl3UJvwjylsMjCT4VjbqARjo7eNce+CfUPyILDk62JV7q1N/kY22Sa73 2Y+yFvPAUldjV5TCisa6JiTn6NYro/VI6qPJm/kZHP2QDFbo5gxDiXeJ1dkfm89n/9 wYBYKiH9zERjkUI4X/Uepj9Dpf1t4BeWZD9skkmw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jacek Tomaka , "Peter Zijlstra (Intel)" , Linus Torvalds , Thomas Gleixner , Ingo Molnar , Sasha Levin Subject: [PATCH 4.9 40/59] perf/x86/intel: Add support/quirk for the MISPREDICT bit on Knights Landing CPUs Date: Mon, 8 Oct 2018 20:31:47 +0200 Message-Id: <20181008175550.673563753@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181008175546.620836256@linuxfoundation.org> References: <20181008175546.620836256@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jacek Tomaka [ Upstream commit 16160c1946b702dcfa95ef63389a56deb2f1c7cb ] Problem: perf did not show branch predicted/mispredicted bit in brstack. Output of perf -F brstack for profile collected Before: 0x4fdbcd/0x4fdc03/-/-/-/0 0x45f4c1/0x4fdba0/-/-/-/0 0x45f544/0x45f4bb/-/-/-/0 0x45f555/0x45f53c/-/-/-/0 0x7f66901cc24b/0x45f555/-/-/-/0 0x7f66901cc22e/0x7f66901cc23d/-/-/-/0 0x7f66901cc1ff/0x7f66901cc20f/-/-/-/0 0x7f66901cc1e8/0x7f66901cc1fc/-/-/-/0 After: 0x4fdbcd/0x4fdc03/P/-/-/0 0x45f4c1/0x4fdba0/P/-/-/0 0x45f544/0x45f4bb/P/-/-/0 0x45f555/0x45f53c/P/-/-/0 0x7f66901cc24b/0x45f555/P/-/-/0 0x7f66901cc22e/0x7f66901cc23d/P/-/-/0 0x7f66901cc1ff/0x7f66901cc20f/P/-/-/0 0x7f66901cc1e8/0x7f66901cc1fc/P/-/-/0 Cause: As mentioned in Software Development Manual vol 3, 17.4.8.1, IA32_PERF_CAPABILITIES[5:0] indicates the format of the address that is stored in the LBR stack. Knights Landing reports 1 (LBR_FORMAT_LIP) as its format. Despite that, registers containing FROM address of the branch, do have MISPREDICT bit but because of the format indicated in IA32_PERF_CAPABILITIES[5:0], LBR did not read MISPREDICT bit. Solution: Teach LBR about above Knights Landing quirk and make it read MISPREDICT bit. Signed-off-by: Jacek Tomaka Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20180802013830.10600-1-jacekt@dugeo.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/events/intel/lbr.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -1195,4 +1195,8 @@ void intel_pmu_lbr_init_knl(void) x86_pmu.lbr_sel_mask = LBR_SEL_MASK; x86_pmu.lbr_sel_map = snb_lbr_sel_map; + + /* Knights Landing does have MISPREDICT bit */ + if (x86_pmu.intel_cap.lbr_format == LBR_FORMAT_LIP) + x86_pmu.intel_cap.lbr_format = LBR_FORMAT_EIP_FLAGS; }