From patchwork Sun Feb 4 07:45:25 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yicong Yang X-Patchwork-Id: 13544528 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E4B10C48286 for ; Sun, 4 Feb 2024 07:50:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=3DUX7drMZYEFISTURpqeTgmhV8KY/T3pJ7tBhHr5rwg=; b=v42TfvJnbRNlHz Uwc1sgmMw2wrhroa7usV7n+8R165+yMiQ2hqTE5f57LQxeogBa0sIp0Tp5nOvclzJLTBXpK4LGzez 9tlc5NyTl18765MJnZbc7oCS30bIP/uz1VcctpVxp6hkRBFsMNDSv4uRz6JRaoKZJXzL6CpFOyoVA URDUlXYIm/C42w1toTYbX0RJ2QpQfSMKXOob25WnxubCrPNb7bhAwuP9Tfb9AECMd+ay8nrvp4r5I rUWSJiwEbkzYNpJMzF0SNqgT2+ZaT8atPuEkf/1PXlO+fpbrzoeFttxf36a4g52M2wIBQv6D9i/Ci Kt+/v9K9HVrFnxuZIlDg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rWXGF-00000000M77-35UD; Sun, 04 Feb 2024 07:49:55 +0000 Received: from szxga04-in.huawei.com ([45.249.212.190]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rWXG8-00000000M1p-0VXF for linux-arm-kernel@lists.infradead.org; Sun, 04 Feb 2024 07:49:51 +0000 Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4TSM7z5Bgkz1xnCC; Sun, 4 Feb 2024 15:48:31 +0800 (CST) Received: from canpemm500009.china.huawei.com (unknown [7.192.105.203]) by mail.maildlp.com (Postfix) with ESMTPS id D72DD1404FC; Sun, 4 Feb 2024 15:49:35 +0800 (CST) Received: from localhost.localdomain (10.50.165.33) 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 15.1.2507.35; Sun, 4 Feb 2024 15:49:35 +0800 From: Yicong Yang To: , , , , , CC: , , , Subject: [PATCH 5/7] drivers/perf: hisi_pcie: Relax the check on related events Date: Sun, 4 Feb 2024 15:45:25 +0800 Message-ID: <20240204074527.47110-6-yangyicong@huawei.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20240204074527.47110-1-yangyicong@huawei.com> References: <20240204074527.47110-1-yangyicong@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.50.165.33] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To canpemm500009.china.huawei.com (7.192.105.203) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240203_234948_553400_6DB078A7 X-CRM114-Status: GOOD ( 14.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Junhao He If we use two events with the same filter and related event type (see the following example), the driver check whether they are related events and are in the same group, otherwise the function hisi_pcie_pmu_find_related_event() return -EINVAL, then the 2nd event cannot count but the 1st event is running, although the PCIe PMU has other idle counters. In this case, The perf event scheduler will make the two events to multiplex a counter, if the user use the formula (1st event_value / 2nd event_value) to calculate the bandwidth, he/she won't get the correct value, because they are not counting at the same period. This patch tries to fix this by making the related events to use different idle counters if they are not in the same event group. And finally, I'm going to say. The related events are best used in the same group [1]. There are two ways to know if they are related events. a) By event name, such as the latency events "xxx_latency, xxx_cnt" or bandwidth events "xxx_flux, xxx_time". b) By event type, such as "event=0xXXXX, event=0x1XXXX". Use group to count the related events: [1] -e "{pmu_name/xxx_latency,port=1/,pmu_name/xxx_cnt,port=1/}" example: 1st event: hisi_pcie0_core1/event=0x804,port=1 2nd event: hisi_pcie0_core1/event=0x10804,port=1 test cmd: perf stata -e hisi_pcie0_core1/event=0x804,port=1/ \ -e hisi_pcie0_core1/event=0x10804,port=1/ before patch: 25,281 hisi_pcie0_core1/event=0x804,port=1/ (49.91%) 470,598 hisi_pcie0_core1/event=0x10804,port=1/ (50.09%) after patch: 24,147 hisi_pcie0_core1/event=0x804,port=1/ 474,558 hisi_pcie0_core1/event=0x10804,port=1/ Signed-off-by: Junhao He Signed-off-by: Yicong Yang --- drivers/perf/hisilicon/hisi_pcie_pmu.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c index b91f03c02c57..1b45aeb82859 100644 --- a/drivers/perf/hisilicon/hisi_pcie_pmu.c +++ b/drivers/perf/hisilicon/hisi_pcie_pmu.c @@ -408,14 +408,10 @@ static int hisi_pcie_pmu_find_related_event(struct hisi_pcie_pmu *pcie_pmu, if (!sibling) continue; - if (!hisi_pcie_pmu_cmp_event(sibling, event)) - continue; - /* Related events must be used in group */ - if (sibling->group_leader == event->group_leader) + if (hisi_pcie_pmu_cmp_event(sibling, event) && + sibling->group_leader == event->group_leader) return idx; - else - return -EINVAL; } return idx;