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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A433EB64D7 for ; Tue, 20 Jun 2023 09:09:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231179AbjFTJJ6 (ORCPT ); Tue, 20 Jun 2023 05:09:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229597AbjFTJJ5 (ORCPT ); Tue, 20 Jun 2023 05:09:57 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF572C9; Tue, 20 Jun 2023 02:09:54 -0700 (PDT) Received: from canpemm500009.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4QlgnP0kByz1FDfh; Tue, 20 Jun 2023 17:09:45 +0800 (CST) Received: from [10.67.102.169] (10.67.102.169) by canpemm500009.china.huawei.com (7.192.105.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Tue, 20 Jun 2023 17:09:46 +0800 CC: , , , , Subject: Re: [PATCH v4 4/5] hwtracing: hisi_ptt: Advertise PERF_PMU_CAP_NO_EXCLUDE for PTT PMU To: hejunhao , , , , , , References: <20230606142244.10939-1-yangyicong@huawei.com> <20230606142244.10939-5-yangyicong@huawei.com> <01c39cb9-e56a-862b-2d99-024b7ba5a769@huawei.com> From: Yicong Yang Message-ID: Date: Tue, 20 Jun 2023 17:09:46 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.1 MIME-Version: 1.0 In-Reply-To: <01c39cb9-e56a-862b-2d99-024b7ba5a769@huawei.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.102.169] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500009.china.huawei.com (7.192.105.203) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hi Junhao, On 2023/6/19 21:00, hejunhao wrote: > Hi, Yicong > > > On 2023/6/6 22:22, Yicong Yang wrote: >> From: Yicong Yang >> >> The PTT trace collects PCIe TLP headers from the PCIe link and don't >> have the ability to exclude certain context. It doesn't support itrace >> as well. So only advertise PERF_PMU_CAP_NO_EXCLUDE. This will greatly >> save the storage of final data. Tested tracing idle link for ~15s, >> without this patch we'll collect ~28.682MB data for context related >> information and with this patch it reduced to ~0.226MB. >> >> Reviewed-by: Jonathan Cameron >> Signed-off-by: Yicong Yang >> --- >>   drivers/hwtracing/ptt/hisi_ptt.c | 2 +- >>   1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c >> index 5c7e93e7705f..ff2c16efe5b1 100644 >> --- a/drivers/hwtracing/ptt/hisi_ptt.c >> +++ b/drivers/hwtracing/ptt/hisi_ptt.c >> @@ -1210,7 +1210,7 @@ static int hisi_ptt_register_pmu(struct hisi_ptt *hisi_ptt) >>         hisi_ptt->hisi_ptt_pmu = (struct pmu) { >>           .module        = THIS_MODULE, >> -        .capabilities    = PERF_PMU_CAP_EXCLUSIVE | PERF_PMU_CAP_ITRACE, >> +        .capabilities    = PERF_PMU_CAP_NO_EXCLUDE, > > According to the error prompt of function hisi_ptt_trace_start(). > https://elixir.bootlin.com/linux/v6.4-rc7/source/drivers/hwtracing/ptt/hisi_ptt.c#L197 > > You may be need to keep advertise PERF_PMU_CAP_EXCLUSIVE? > Such pmus can only have one event scheduled at a time, if not the perf > tool will report device busy. > Thanks for point it out. Checking [1] I think we still need this flag here, will add it back. [1] https://github.com/torvalds/linux/blob/v6.4-rc6/kernel/events/core.c#L5054 Thanks.