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=-3.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_MED, 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 9DC8AC28CF6 for ; Thu, 2 Aug 2018 01:39:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22A1220862 for ; Thu, 2 Aug 2018 01:39:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=dugeo-com.20150623.gappssmtp.com header.i=@dugeo-com.20150623.gappssmtp.com header.b="HX+qlXqH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 22A1220862 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=dugeo.com 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 S1731991AbeHBD1f (ORCPT ); Wed, 1 Aug 2018 23:27:35 -0400 Received: from mail-pg1-f182.google.com ([209.85.215.182]:35425 "EHLO mail-pg1-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730038AbeHBD1f (ORCPT ); Wed, 1 Aug 2018 23:27:35 -0400 Received: by mail-pg1-f182.google.com with SMTP id e6-v6so311350pgv.2 for ; Wed, 01 Aug 2018 18:38:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=dugeo-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id; bh=nm0UxIhPx1cXqGRwecH+OO05GzRWqNwW8UAtOCMK7/g=; b=HX+qlXqHVdu5baAMRSed5b7l7Bl944CtnelvyzdugPnFnZPJ73k19ArZFRXFGhmNVF SupLxmicTNDZBtk2NrS761w2hDEVWBBYtrTl7fq2UZFMswZVWNbh+D/U8irtavKFHQq/ 0dZZJZAgN5GZgc+XnnFi/pF7Xe4lCmbiQJMXeHp7T+ueE6BRFyh/0IGTd5OywCrXm6Cz 1s0plRxGGurfjtaEqvEWBzDlqAZ7vPsxsu5yUQnnQQ+NlgD1CKvfB2z71YqTx2jJ3ah6 3dSwDozW11/8EeHhmlx+1M8xvZLswTYJgaQNt2EfQ1EWeg3/ZyiwJVxWlDAQcauCkXQO 9ZYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=nm0UxIhPx1cXqGRwecH+OO05GzRWqNwW8UAtOCMK7/g=; b=ZMeoWpdPagiLhJvyLiCloPROYfcOBfS2BfyHPYwBjQjQ/mn8jNUPRirHjGhSIqgKyI sfUT/xhqWgheemsYXVKgEDC656+6fXoAuL+0pmXANFVvKZrfxBT3738E6Ics4mQx9cP7 ioSgrOohxIwVxjRzYFu2i4WoomNCy8tSpN5w4hWthgfnGWFLaeMDhXg3PK64B2YlswLw m6enktLVOTk8oK3poDQ70iTqCi5q0MnB6SUTlYU3Mu7LpsAMA1I0Yl8OJ+BdenoTFUCB e4Tjh4HDT2zmQETv4GnwnnYZ1rz66YleRgV+B/q35a6nutV+pR832jcL9cZkO2Wz3wRy 4jsQ== X-Gm-Message-State: AOUpUlFFompSM2kuQjcEgY0/DNtqCSerc2/wDoAsCUwFrq9X3lzIIXf7 7nWL0hMKech24feuI5so5jpolA== X-Google-Smtp-Source: AAOMgpcKWC6BJLamrB+NPI5wzLRZggiBZbmVi/6C+/LpUzhSQlqiN3Ky8xyGIeER6nzYLMdaGHvCpg== X-Received: by 2002:a63:40c7:: with SMTP id n190-v6mr707666pga.116.1533173935985; Wed, 01 Aug 2018 18:38:55 -0700 (PDT) Received: from bud178.dugeo.com ([116.212.202.58]) by smtp.gmail.com with ESMTPSA id 14-v6sm503775pft.93.2018.08.01.18.38.52 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 Aug 2018 18:38:54 -0700 (PDT) From: Jacek Tomaka To: Peter Zijlstra , linux-kernel@vger.kernel.org, Ingo Molnar , Thomas Gleixner Cc: Jacek Tomaka Subject: [PATCH v4] perf/x86/intel: Add support for MISPREDICT bit on Knights Landing cpus Date: Thu, 2 Aug 2018 09:38:30 +0800 Message-Id: <20180802013830.10600-1-jacekt@dugeo.com> X-Mailer: git-send-email 2.17.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jacek Tomaka 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 --- arch/x86/events/intel/lbr.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c index cf372b9055..81fe5047c6 100644 --- a/arch/x86/events/intel/lbr.c +++ b/arch/x86/events/intel/lbr.c @@ -1230,4 +1230,8 @@ 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; } -- 2.17.0