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,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, 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 69D0BCA9EA0 for ; Sat, 26 Oct 2019 03:25:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A2E221872 for ; Sat, 26 Oct 2019 03:25:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="F+wGFwf3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726330AbfJZDZS (ORCPT ); Fri, 25 Oct 2019 23:25:18 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:43440 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726010AbfJZDZO (ORCPT ); Fri, 25 Oct 2019 23:25:14 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x9Q3OPgI051029; Sat, 26 Oct 2019 03:24:52 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=corp-2019-08-05; bh=JH5g7kGl18GmOwGR9exKyCwwdZcdLzKY/dznWLlvQQA=; b=F+wGFwf3/iCqaqO3tACZ9VBzsZnhkahSeBlmxuAVt93LTYHTgF6aLfc8S9hXR0DAsDqj 6+mE2DfrYXWU9YHcQ0BYx/WS1c6G0hGgueOQ8f8dJxlqV/J7A6DqVoS2n8H/mRQkfH9n Nklx70T+kQ2sSqgYaG9aYf3XRXOQ8Z9QX00g89fD9qqnCrn7curvDvkaOxavlx3C+b87 FkwpRq2OYrwyC3aVTBXHVPk5xn6NUjlMnyF3X6KgLj9gdKo5tCimntE6JGC651l1CH31 zSQM/Zg9rIamN2C4IcHJTxsRsI5u4vBzjUNPCUemOcqhE+Ev/ZNZlbkTZqWSwi4UC8y3 Dg== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 2vvdjtr51n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 26 Oct 2019 03:24:51 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x9Q3OJEc082815; Sat, 26 Oct 2019 03:24:51 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3030.oracle.com with ESMTP id 2vvc6mmwkp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 26 Oct 2019 03:24:50 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x9Q3OoJl025657; Sat, 26 Oct 2019 03:24:50 GMT Received: from z2.cn.oracle.com (/10.182.71.218) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 25 Oct 2019 20:24:50 -0700 From: Zhenzhong Duan To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org, mtosatti@redhat.com, joao.m.martins@oracle.com, rafael.j.wysocki@intel.com, rkrcmar@redhat.com, pbonzini@redhat.com, Zhenzhong Duan Subject: [PATCH 4/5] cpuidle-haltpoll: add a check to ensure grow start value is nonzero Date: Sat, 26 Oct 2019 11:23:58 +0800 Message-Id: <1572060239-17401-5-git-send-email-zhenzhong.duan@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1572060239-17401-1-git-send-email-zhenzhong.duan@oracle.com> References: <1572060239-17401-1-git-send-email-zhenzhong.duan@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9421 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=875 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910260033 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9421 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=954 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910260034 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org dev->poll_limit_ns could be zeroed in certain cases (e.g. by guest_halt_poll_shrink). If guest_halt_poll_grow_start is zero, dev->poll_limit_ns will never be larger than zero. Signed-off-by: Zhenzhong Duan --- drivers/cpuidle/governors/haltpoll.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c index 7a703d2..4b00d7a 100644 --- a/drivers/cpuidle/governors/haltpoll.c +++ b/drivers/cpuidle/governors/haltpoll.c @@ -77,7 +77,7 @@ static int haltpoll_select(struct cpuidle_driver *drv, static void adjust_poll_limit(struct cpuidle_device *dev, unsigned int block_us) { - unsigned int val; + unsigned int val, grow_start; u64 block_ns = block_us*NSEC_PER_USEC; /* Grow cpu_halt_poll_us if @@ -86,8 +86,17 @@ static void adjust_poll_limit(struct cpuidle_device *dev, unsigned int block_us) if (block_ns > dev->poll_limit_ns && block_ns <= guest_halt_poll_ns) { val = dev->poll_limit_ns * guest_halt_poll_grow; - if (val < guest_halt_poll_grow_start) - val = guest_halt_poll_grow_start; + /* + * vcpu->halt_poll_ns needs a nonzero start point to grow if + * it's zero. + */ + grow_start = guest_halt_poll_grow_start; + if (!grow_start) + grow_start = 1; + + if (val < grow_start) + val = grow_start; + if (val > guest_halt_poll_ns) val = guest_halt_poll_ns; -- 1.8.3.1