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=unavailable 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 CF867C31E4D for ; Fri, 14 Jun 2019 20:33:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C9EA217F9 for ; Fri, 14 Jun 2019 20:33:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560544392; bh=OG2a7VMG5z5jIVJknxckUrEivgArjIq1V+A3jrVfaTY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mPUNuE/kAGkOlgD6OThl4QXpM8DPFp0WtUleRZSQbxLZvtm5lHBay7l6BxPZkFqsR YYd/WvO7xhlIJAAtDiiZBSBE9gSOxBrzs1afHEKj92FcYVWcjmcjtcKfj/djl71jV+ X0XzXhPDTWCnH6qKBc9i1WRjLDsFiFnclQiwKPX4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727735AbfFNUae (ORCPT ); Fri, 14 Jun 2019 16:30:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:53532 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727708AbfFNUac (ORCPT ); Fri, 14 Jun 2019 16:30:32 -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 F2AA421851; Fri, 14 Jun 2019 20:30:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560544232; bh=OG2a7VMG5z5jIVJknxckUrEivgArjIq1V+A3jrVfaTY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tTy0DqFuTxEDE4iTx3s3hZnXXou0l8cQnJzhAqqcDci8yp/OloNGKP4UQTzF5JxTs woy8ESeQy3yUzPTuh0qErC2TaNg88pc1pMXH4RED2akvVZL8JqhxLkqbB0Ily7XVk6 u5mhNNNLOSBoCXZpL38cK0o9ZESgQrHmOtrI+LbQ= 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 4.14 15/27] sparc: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD Date: Fri, 14 Jun 2019 16:30:04 -0400 Message-Id: <20190614203018.27686-15-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190614203018.27686-1-sashal@kernel.org> References: <20190614203018.27686-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 eceb0215bdee..58ea64a29d5f 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