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=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 7C84EC5DF63 for ; Wed, 6 Nov 2019 11:56:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4669321848 for ; Wed, 6 Nov 2019 11:56:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="moDcX+2w" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730155AbfKFL4H (ORCPT ); Wed, 6 Nov 2019 06:56:07 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:40192 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725856AbfKFL4G (ORCPT ); Wed, 6 Nov 2019 06:56:06 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xA6Bs8Ph049980; Wed, 6 Nov 2019 11:55:44 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=EPKzfVRRWTGlG40d7rhnldMOWGwhBLJaJGkHe+80yiw=; b=moDcX+2wcqRmyIvB8FKPWFflJ+KDihvj4whWqFyfE71UiGmuXEcGhGKPKz9FEVAUbH5x B8NYPal0fGdPgvfDBKNL4KoNIBWB8AEtJMFNz42PELtAui17slpTuYsQf8+n4KNDxUkJ Zom61tgP25VcZthq73P1v19qA5b1galtl0XPq1zc73QravPV9ZTtnkTE5Ghd+V0JLCv4 vWf/9DK4tmPXPo35oLEfxdYPttPAW5yszxDrkHAIeY2uddzROD/Qb/+KFIDMP5XTisKo Itv9SGVp5JZ6a+oOi9sOiR+nNKxmSFlY5KfLLj7Llty49P8C2qEvmyy0zX7I2pVDd4Y/ Wg== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 2w11rq5m5s-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Nov 2019 11:55:43 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id xA6BsLeu051863; Wed, 6 Nov 2019 11:55:43 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 2w31639sgh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Nov 2019 11:55:42 +0000 Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id xA6BtffF022120; Wed, 6 Nov 2019 11:55:41 GMT Received: from z2.cn.oracle.com (/10.182.71.218) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 06 Nov 2019 03:55:41 -0800 From: Zhenzhong Duan To: linux-kernel@vger.kernel.org Cc: pbonzini@redhat.com, rkrcmar@redhat.com, rafael.j.wysocki@intel.com, joao.m.martins@oracle.com, mtosatti@redhat.com, kvm@vger.kernel.org, linux-pm@vger.kernel.org, Zhenzhong Duan Subject: [PATCH RESEND v2 1/4] cpuidle-haltpoll: ensure grow start value is nonzero Date: Wed, 6 Nov 2019 19:54:59 +0800 Message-Id: <1573041302-4904-2-git-send-email-zhenzhong.duan@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1573041302-4904-1-git-send-email-zhenzhong.duan@oracle.com> References: <1573041302-4904-1-git-send-email-zhenzhong.duan@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9432 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=808 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060119 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9432 signatures=668685 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=886 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060119 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org dev->poll_limit_ns could be zeroed in certain cases (e.g. by guest_halt_poll_ns = 0). If guest_halt_poll_grow_start is zero, dev->poll_limit_ns will never be bigger than zero. Use param callback to avoid writing zero to guest_halt_poll_grow_start. Signed-off-by: Zhenzhong Duan --- drivers/cpuidle/governors/haltpoll.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c index 7a703d2..660859d 100644 --- a/drivers/cpuidle/governors/haltpoll.c +++ b/drivers/cpuidle/governors/haltpoll.c @@ -20,6 +20,26 @@ #include #include +static int grow_start_set(const char *val, const struct kernel_param *kp) +{ + int ret; + unsigned int n; + + if (!val) + return -EINVAL; + + ret = kstrtouint(val, 0, &n); + if (ret || !n) + return -EINVAL; + + return param_set_uint(val, kp); +} + +static const struct kernel_param_ops grow_start_ops = { + .set = grow_start_set, + .get = param_get_uint, +}; + static unsigned int guest_halt_poll_ns __read_mostly = 200000; module_param(guest_halt_poll_ns, uint, 0644); @@ -33,7 +53,7 @@ /* value in us to start growing per-cpu halt_poll_ns */ static unsigned int guest_halt_poll_grow_start __read_mostly = 50000; -module_param(guest_halt_poll_grow_start, uint, 0644); +module_param_cb(guest_halt_poll_grow_start, &grow_start_ops, &guest_halt_poll_grow_start, 0644); /* allow shrinking guest halt poll */ static bool guest_halt_poll_allow_shrink __read_mostly = true; -- 1.8.3.1