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=-8.8 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 F3CD2C48BE9 for ; Mon, 24 Jun 2019 10:18:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C2DDF2146E for ; Mon, 24 Jun 2019 10:18:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561371537; bh=6OdPh8UvNgFw9kAu6ULVURDzR2ajJLVxWU0NRDBdpe0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GyBhPVQYdAKzre/yk8ZdVoOOOjOE3J2dMFn2rrPmSBAteEbPpv6JAa6V6YbOoB52/ V/GUXWyaJdxjqrRd/RlD7kIAhBPlTj5zE/MEmXjpgg8PIB6fGYzSJhxgeUJzsgmwFz BB828fG1+px5oZAErDxt2pkMlhCm12Uerd0rT0Ac= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728677AbfFXKPn (ORCPT ); Mon, 24 Jun 2019 06:15:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:53044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729706AbfFXKPm (ORCPT ); Mon, 24 Jun 2019 06:15:42 -0400 Received: from localhost (f4.8f.5177.ip4.static.sl-reverse.com [119.81.143.244]) (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 6456A2089F; Mon, 24 Jun 2019 10:15:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561371341; bh=6OdPh8UvNgFw9kAu6ULVURDzR2ajJLVxWU0NRDBdpe0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K/QllV4T15nfPeq9EY5tYSi16iLAylaiJY1d6mSaDTaD+9wIYSQUEddMbVVqEdkGY zRabsYg1U52ipTsaCbZazBtfQHYCdOtsabNh2V+Ljj7GjW0XvkW+Fu/tTG4YvSpKp8 PyfVTBSkKbYFAuP/wXTHk8oVgkU4HyTzHHPsovXA= 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 5.1 066/121] sparc: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD Date: Mon, 24 Jun 2019 17:56:38 +0800 Message-Id: <20190624092324.192490402@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190624092320.652599624@linuxfoundation.org> References: <20190624092320.652599624@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 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