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=-15.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 78FAFC47083 for ; Wed, 2 Jun 2021 08:45:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59079613D2 for ; Wed, 2 Jun 2021 08:45:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232778AbhFBIrX (ORCPT ); Wed, 2 Jun 2021 04:47:23 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:3346 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232795AbhFBIrS (ORCPT ); Wed, 2 Jun 2021 04:47:18 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Fw2YD3k11z19Ps4; Wed, 2 Jun 2021 16:40:48 +0800 (CST) Received: from dggema757-chm.china.huawei.com (10.1.198.199) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Wed, 2 Jun 2021 16:45:31 +0800 Received: from [127.0.0.1] (10.69.38.203) by dggema757-chm.china.huawei.com (10.1.198.199) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Wed, 2 Jun 2021 16:45:30 +0800 Subject: Re: [PATCH v2 1/9] perf: Add EVENT_ATTR_ID to simplify event attributes To: Will Deacon , Qi Liu CC: , , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Linuxarm References: <1621417919-6632-1-git-send-email-liuqi115@huawei.com> <1621417919-6632-2-git-send-email-liuqi115@huawei.com> <20210601131020.GD28025@willie-the-truck> From: "liuqi (BA)" Message-ID: <30abdbec-3174-1f8a-47d4-63a4de3b1e47@huawei.com> Date: Wed, 2 Jun 2021 16:45:23 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20210601131020.GD28025@willie-the-truck> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit X-Originating-IP: [10.69.38.203] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggema757-chm.china.huawei.com (10.1.198.199) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Will, Thanks for reviewing this patch. On 2021/6/1 21:10, Will Deacon wrote: > On Wed, May 19, 2021 at 05:51:51PM +0800, Qi Liu wrote: >> Similar EVENT_ATTR macros are defined in many PMU drivers, >> like HiSilicon PMU driver, Arm PMU driver, Arm SMMU PMU >> driver. So Add a generic macro to simplify code. >> >> Cc: Peter Zijlstra >> Cc: Ingo Molnar >> Cc: Arnaldo Carvalho de Melo >> Cc: Mark Rutland >> Cc: Alexander Shishkin >> Signed-off-by: Qi Liu >> --- >> include/linux/perf_event.h | 6 ++++++ >> kernel/events/core.c | 2 ++ >> 2 files changed, 8 insertions(+) >> >> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h >> index f5a6a2f..d0aa74e 100644 >> --- a/include/linux/perf_event.h >> +++ b/include/linux/perf_event.h >> @@ -1576,6 +1576,12 @@ static struct perf_pmu_events_attr _var = { \ >> .event_str = _str, \ >> }; >> >> +#define PMU_EVENT_ATTR_ID(_name, _id) \ >> + (&((struct perf_pmu_events_attr[]) { \ >> + { .attr = __ATTR(_name, 0444, perf_event_sysfs_show, NULL), \ >> + .id = _id, } \ >> + })[0].attr.attr) >> + >> #define PMU_FORMAT_ATTR(_name, _format) \ >> static ssize_t \ >> _name##_show(struct device *dev, \ >> diff --git a/kernel/events/core.c b/kernel/events/core.c >> index 0ac818b..330d9cc 100644 >> --- a/kernel/events/core.c >> +++ b/kernel/events/core.c >> @@ -13295,6 +13295,8 @@ ssize_t perf_event_sysfs_show(struct device *dev, struct device_attribute *attr, >> >> if (pmu_attr->event_str) >> return sprintf(page, "%s\n", pmu_attr->event_str); >> + else >> + return sprintf(page, "config=%#llx\n", pmu_attr->id); > > I think it's a really bad idea to hardcode this here. For example, I think > this patch series breaks user ABI for the SMMU PMU which used to print: > > "event=0x%02llx\n" > > and by the looks of it many of the other conversions are unsound too. > Got it, so I'll use pmu_attr->event_str here, for example, SMMU_EVENT_ATTR(cycles, "event=0x00") As PMU_EVENT_ATTR_STRING is already defined in linux/perf_event.h，and is used in drivers of multi architectures, add a new common macro might be better than modify PMU_EVENT_ATTR_STRING. Do you have any suggestion about the name of new common macro? Thanks, Qi > I'm all for a common macro, but the string needs to be determined by the > driver. > > Will > . >