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=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 E8E42C04A6B for ; Wed, 8 May 2019 09:36:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C5131216F4 for ; Wed, 8 May 2019 09:36:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726404AbfEHJgk (ORCPT ); Wed, 8 May 2019 05:36:40 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:45714 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726847AbfEHJgj (ORCPT ); Wed, 8 May 2019 05:36:39 -0400 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id C7F2825680005E233F3B; Wed, 8 May 2019 17:36:37 +0800 (CST) Received: from [127.0.0.1] (10.177.223.23) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.439.0; Wed, 8 May 2019 17:36:30 +0800 Subject: Re: [PATCH v3 0/5] arm64: SPE ACPI enablement To: Jeremy Linton , CC: , , , , , , , , , , Hongbo Yao , Alexander Shishkin References: <20190503232407.37195-1-jeremy.linton@arm.com> <5eaa1607-4bf0-a320-e9cf-2d51eca912c6@huawei.com> <82032e5b-0cb5-e48f-ab51-ba5d5f9dceec@arm.com> From: Hanjun Guo Message-ID: <819de863-92ff-51c5-9c35-880db4f6a922@huawei.com> Date: Wed, 8 May 2019 17:35:51 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <82032e5b-0cb5-e48f-ab51-ba5d5f9dceec@arm.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.223.23] X-CFilter-Loop: Reflected Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org +Cc Alexander. On 2019/5/8 1:58, Jeremy Linton wrote: > Hi, > > On 5/4/19 6:06 AM, Hanjun Guo wrote: >> Hi Jeremy, Mark, >> >> On 2019/5/4 7:24, Jeremy Linton wrote: >>> This patch series enables the Arm Statistical Profiling >>> Extension (SPE) on ACPI platforms. >>> >>> This is possible because ACPI 6.3 uses a previously >>> reserved field in the MADT to store the SPE interrupt >>> number, similarly to how the normal PMU is described. >>> If a consistent valid interrupt exists across all the >>> cores in the system, a platform device is registered. >>> That then triggers the SPE module, which runs as normal. >>> >>> We also add the ability to parse the PPTT for IDENTICAL >>> cores. We then use this to sanity check the single SPE >>> device we create. This creates a bit of a problem with >>> respect to the specification though. The specification >>> says that its legal for multiple tree's to exist in the >>> PPTT. We handle this fine, but what happens in the >>> case of multiple tree's is that the lack of a common >>> node with IDENTICAL set forces us to assume that there >>> are multiple non-IDENTICAL cores in the machine. >> >> Adding this patch set on top of latest mainline kernel, >> and tested on D06 which has the SPE feature, in boot message >> shows it was probed successfully: >> >> arm_spe_pmu arm,spe-v1: probed for CPUs 0-95 [max_record_sz 128, align 4, features 0x7] >> >> but when I test it with spe events such as >> >> perf record -c 1024 -e arm_spe_0/branch_filter=0/ -o spe ls >> >> it fails with: >> failed to mmap with 12 (Cannot allocate memory), >> >> Confirmed that patch [0] is merged and other perf events are working >> fine. > > Its pretty easy to get into the weeds with this driver, does it work with examples like: > > https://lkml.org/lkml/2018/1/14/122 No, not work at all. SPE works on 5.0, but not work after 5.1-rc1, bisected to this commit: 5768402fd9c6 perf/ring_buffer: Use high order allocations for AUX buffers optimistically Cced Alexander as well as Alexander is the author of above patch. Thanks Hanjun