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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 88284C31E4B for ; Fri, 14 Jun 2019 20:36:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B57721848 for ; Fri, 14 Jun 2019 20:36:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560544592; bh=KKYH9BGJ4VGKUCyRJKTlgi3ZCPu5H0tuZNbJsslSLw0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ulZRAuWNMU4M52QVlIx5bT11bryWaPzR51RD86z4UbKcRkRAkKFW9YGOHUR0hhkrz QWyXfXEsGbad2I6Y85YWeUAcKpYvMOsXBDEpyDUizDaGMh+PK+qekrITB6t2JDL9KD Au8hpWspZxAoTHITptMWfTlhUZgKRTCF9YxXKX1o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728369AbfFNUga (ORCPT ); Fri, 14 Jun 2019 16:36:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:51838 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727071AbfFNU3k (ORCPT ); Fri, 14 Jun 2019 16:29:40 -0400 Received: from sasha-vm.mshome.net (unknown [131.107.159.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 85DA82184B; Fri, 14 Jun 2019 20:29:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560544179; bh=KKYH9BGJ4VGKUCyRJKTlgi3ZCPu5H0tuZNbJsslSLw0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zoVQAQzW+aPveniH704Bcz1PS8BkkLc23zskoydff9FUXgEBeHtOrowbDuOrrNjsr 8EHXvL4ABN2cJWUGz97wDH50cZU/aTCgzCDp0LXUr/bOLy7NQCYjl1vUmuwElFIPj1 7r1Zd3rMxEapwlKDP1hgo45KMzdH0GXQ4hezJOBg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Young Xiao <92siuyang@gmail.com>, "David S . Miller" , Sasha Levin , sparclinux@vger.kernel.org Subject: [PATCH AUTOSEL 5.1 37/59] sparc: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD Date: Fri, 14 Jun 2019 16:28:21 -0400 Message-Id: <20190614202843.26941-37-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190614202843.26941-1-sashal@kernel.org> References: <20190614202843.26941-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Young Xiao <92siuyang@gmail.com> [ Upstream commit 56cd0aefa475079e9613085b14a0f05037518fed ] The PERF_EVENT_IOC_PERIOD ioctl command can be used to change the sample period of a running perf_event. Consequently, when calculating the next event period, the new period will only be considered after the previous one has overflowed. This patch changes the calculation of the remaining event ticks so that they are offset if the period has changed. See commit 3581fe0ef37c ("ARM: 7556/1: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD") for details. Signed-off-by: Young Xiao <92siuyang@gmail.com> Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- arch/sparc/kernel/perf_event.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c index 6de7c684c29f..a58ae9c42803 100644 --- a/arch/sparc/kernel/perf_event.c +++ b/arch/sparc/kernel/perf_event.c @@ -891,6 +891,10 @@ static int sparc_perf_event_set_period(struct perf_event *event, s64 period = hwc->sample_period; int ret = 0; + /* The period may have been changed by PERF_EVENT_IOC_PERIOD */ + if (unlikely(period != hwc->last_period)) + left = period - (hwc->last_period - left); + if (unlikely(left <= -period)) { left = period; local64_set(&hwc->period_left, left); -- 2.20.1