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 0C70FC31E4B for ; Fri, 14 Jun 2019 20:32:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C66092080A for ; Fri, 14 Jun 2019 20:32:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560544348; bh=jhQqnymgbcED4Wg31HonswJM/vkpXR8hme/VKMnjuzU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HCpMAnqh4tOCcqTTgZZfbtM8nJhyObp/YoQzQGwkJnu1x/Ps9eOubCq40hQuIkqdo EFezbMedCY7bvBst63kriCc4XFLGBwXpdSylcsMLkD4hGSgb77IY9n2v5RDKkLE51X 3cIfcgmcZJEroCePBbepj+Czq5Fi7/6s0FkKZySM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728239AbfFNUc1 (ORCPT ); Fri, 14 Jun 2019 16:32:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:54368 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727876AbfFNUap (ORCPT ); Fri, 14 Jun 2019 16:30:45 -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 C413F21880; Fri, 14 Jun 2019 20:30:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560544244; bh=jhQqnymgbcED4Wg31HonswJM/vkpXR8hme/VKMnjuzU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mHZNJYVv1PfHpZE+nzDd3MLZxnQRyp+dkNpYQLEIhYbaDsLOzT7dU9gl4Mj0I3Hpf n5SxjHPNtiobe80lL/Z32slZnasfBUnJ+Kdubqh85YrAl+HY6Q8IHzTXXnh0o3nNKN FmnCp5oTKVKcTqrVvTQQeqW4XrKAztrJ5PQsCbYc= 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 4.9 10/18] sparc: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD Date: Fri, 14 Jun 2019 16:30:26 -0400 Message-Id: <20190614203037.27910-10-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190614203037.27910-1-sashal@kernel.org> References: <20190614203037.27910-1-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 71e7f77f6776..84a80cd004eb 100644 --- a/arch/sparc/kernel/perf_event.c +++ b/arch/sparc/kernel/perf_event.c @@ -889,6 +889,10 @@ 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