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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 44529C606C1 for ; Mon, 8 Jul 2019 15:18:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13040216C4 for ; Mon, 8 Jul 2019 15:18:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599139; bh=8WFReox3sk8YgaXFZ4lhamtoghRFzlHCt7+B7fMxcok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EGziW+RQWGLwxbeRMshJV40v4GtfJc+vjxrVgoZTxuD1rBcy2uv+be7BOj13wQ44p 17TzWMNt2HGxnkXUedQYn9o7z1eecThZjrG7JhonDTtSYlcnv0/WuDIH73SU6nDeDc zl2LcSbPHrWj42CvNhSR7po8wexG8BXhWRZxjsDs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733151AbfGHPS6 (ORCPT ); Mon, 8 Jul 2019 11:18:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:42914 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730690AbfGHPSy (ORCPT ); Mon, 8 Jul 2019 11:18:54 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 692B8216FD; Mon, 8 Jul 2019 15:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562599133; bh=8WFReox3sk8YgaXFZ4lhamtoghRFzlHCt7+B7fMxcok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YUGgrLwl34BTu+poR7OzP/rVrBHzozUNZ5/4d5yZr/OEubDJf2cCQJRupTs6MjFGl nKqutudNpYAlYpjQCbKWFYDWnt7fH9/mWC4W8xtFhP+/Agb1QQlhEvMnwq132q6ASE D0/vod8qqWnbMFkBtEImukI7BT1r/ayCjyHhTbis= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Young Xiao <92siuyang@gmail.com>, "David S. Miller" , Sasha Levin Subject: [PATCH 4.9 017/102] sparc: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD Date: Mon, 8 Jul 2019 17:12:10 +0200 Message-Id: <20190708150527.052385847@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190708150525.973820964@linuxfoundation.org> References: <20190708150525.973820964@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ 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