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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 CEF97C433DF for ; Mon, 10 Aug 2020 22:37:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFD27206DA for ; Mon, 10 Aug 2020 22:37:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727023AbgHJWhN (ORCPT ); Mon, 10 Aug 2020 18:37:13 -0400 Received: from mga06.intel.com ([134.134.136.31]:13676 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726761AbgHJWhM (ORCPT ); Mon, 10 Aug 2020 18:37:12 -0400 IronPort-SDR: AceMMsjUXLeO317Nl5OV6ev5SJK6p9jN1iC/Seyo5m4/L18o+/Mz0IwJ+1CYMdYSgzljlgwJ4o SUHxxIbGCfFQ== X-IronPort-AV: E=McAfee;i="6000,8403,9709"; a="215146132" X-IronPort-AV: E=Sophos;i="5.75,458,1589266800"; d="scan'208";a="215146132" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Aug 2020 15:37:11 -0700 IronPort-SDR: 9LK8gXSB52smKO7JHoXNyLrAdMmD23DxxTfR+m5ny18Vz3V2XLR8a+/fcob0zWYXcekg2oRQXX e6VIWXGjsDbQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,458,1589266800"; d="scan'208";a="494477392" Received: from linux.intel.com ([10.54.29.200]) by fmsmga006.fm.intel.com with ESMTP; 10 Aug 2020 15:37:11 -0700 Received: from [10.254.81.180] (kliang2-MOBL.ccr.corp.intel.com [10.254.81.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by linux.intel.com (Postfix) with ESMTPS id 0D836580223; Mon, 10 Aug 2020 15:37:09 -0700 (PDT) Subject: Re: [PATCH V6 03/16] perf/core: Add support for PERF_SAMPLE_CODE_PAGE_SIZE To: Peter Zijlstra Cc: acme@kernel.org, mingo@redhat.com, linux-kernel@vger.kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@redhat.com, eranian@google.com, ak@linux.intel.com, dave.hansen@intel.com, kirill.shutemov@linux.intel.com References: <20200810212436.8026-1-kan.liang@linux.intel.com> <20200810212436.8026-4-kan.liang@linux.intel.com> <20200810214100.GL3982@worktop.programming.kicks-ass.net> From: "Liang, Kan" Message-ID: <3313128b-04f3-e5b5-9918-aaed7ede43de@linux.intel.com> Date: Mon, 10 Aug 2020 18:37:08 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200810214100.GL3982@worktop.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/10/2020 5:41 PM, Peter Zijlstra wrote: > On Mon, Aug 10, 2020 at 02:24:23PM -0700, Kan Liang wrote: >> From: Stephane Eranian >> >> When studying code layout, it is useful to capture the page size of the >> sampled code address. >> >> Add a new sample type for code page size. >> The new sample type requires collecting the ip. The code page size can >> be calculated from the IRQ-safe perf_get_page_size(). >> >> Only the generic support is covered. The large PEBS will be disabled >> with this sample type. > > -ENOREASON I think the reason is similar to PERF_SAMPLE_DATA_PAGE_SIZE. For large PEBS, the mapping could be gone for the earlier PEBS records. Invalid page size may be retrieved. I will update the commit message. Thanks, Kan