From patchwork Wed Nov 6 09:08:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhenzhong Duan X-Patchwork-Id: 11229693 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6496C112B for ; Wed, 6 Nov 2019 09:11:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 413622178F for ; Wed, 6 Nov 2019 09:11:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="L6Aemdo9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731528AbfKFJLn (ORCPT ); Wed, 6 Nov 2019 04:11:43 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:45742 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727041AbfKFJLm (ORCPT ); Wed, 6 Nov 2019 04:11:42 -0500 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 xA698wYd116234; Wed, 6 Nov 2019 09:11:25 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=L6Aemdo9fhglASfZz2I71e0bQ6RJFLKi23q2FFx8QEXB8h+shi2JmTu2aijSZBJNxag5 FL8ciWvzZK2/qc2IWw0Gswr9Z9wm931bc3WonurMT9rl0zOVNf0wkNJ9vVdU2kzB1Ecj 2gBv+Hkdq0t1s8Nn9q3SJLlsD3ownbR7HuQ00IGCPxhSa3Msgdmo3ioVM5RRVAefKNAe ST6/7q/FNwlpqE7Pe0zG8o9tJpdEm1kAcS/VpP4JzzcGQ0RztuB5CXkZ4gQt+e709AWQ OhmCYy5JrS56J8x+WBsYni3NYzpoGMnXV6uOtaccfnEPpRm865Yj1jwzOurwWnY7PrY0 Mw== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 2w117u4h0q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Nov 2019 09:11:25 +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 xA6986Ah077631; Wed, 6 Nov 2019 09:09:24 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3030.oracle.com with ESMTP id 2w35pqk36k-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Nov 2019 09:09:24 +0000 Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id xA699N3M001024; Wed, 6 Nov 2019 09:09:23 GMT Received: from z2.cn.oracle.com (/10.182.71.218) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 06 Nov 2019 01:09:23 -0800 From: Zhenzhong Duan To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: pbonzini@redhat.com, rkrcmar@redhat.com, rafael.j.wysocki@intel.com, joao.m.martins@oracle.com, mtosatti@redhat.com, Zhenzhong Duan Subject: [PATCH v2 1/4] cpuidle-haltpoll: ensure grow start value is nonzero Date: Wed, 6 Nov 2019 17:08:49 +0800 Message-Id: <1573031332-2121-2-git-send-email-zhenzhong.duan@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1573031332-2121-1-git-send-email-zhenzhong.duan@oracle.com> References: <1573031332-2121-1-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=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=854 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060096 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=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=932 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060096 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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; From patchwork Wed Nov 6 09:08:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhenzhong Duan X-Patchwork-Id: 11229687 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D7261112B for ; Wed, 6 Nov 2019 09:09:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4BB421848 for ; Wed, 6 Nov 2019 09:09:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="CWii5o0w" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731541AbfKFJJs (ORCPT ); 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Wed, 06 Nov 2019 09:09:27 +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 xA698rfP015319; Wed, 6 Nov 2019 09:09:27 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 2w31631dv1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Nov 2019 09:09:27 +0000 Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id xA699QHM001033; Wed, 6 Nov 2019 09:09:26 GMT Received: from z2.cn.oracle.com (/10.182.71.218) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 06 Nov 2019 01:09:25 -0800 From: Zhenzhong Duan To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: pbonzini@redhat.com, rkrcmar@redhat.com, rafael.j.wysocki@intel.com, joao.m.martins@oracle.com, mtosatti@redhat.com, Zhenzhong Duan Subject: [PATCH v2 2/4] KVM: ensure grow start value is nonzero Date: Wed, 6 Nov 2019 17:08:50 +0800 Message-Id: <1573031332-2121-3-git-send-email-zhenzhong.duan@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1573031332-2121-1-git-send-email-zhenzhong.duan@oracle.com> References: <1573031332-2121-1-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=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=729 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060096 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=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=807 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060096 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org vcpu->halt_poll_ns could be zeroed in certain cases (e.g. by halt_poll_ns = 0). If halt_poll_grow_start is zero, vcpu->halt_poll_ns will never be bigger than zero. Use param callback to avoid writing zero to halt_poll_grow_start. Signed-off-by: Zhenzhong Duan --- virt/kvm/kvm_main.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d6f0696..359516b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -69,6 +69,26 @@ MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); +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, +}; + /* Architectures should define their poll value according to the halt latency */ unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT; module_param(halt_poll_ns, uint, 0644); @@ -81,7 +101,7 @@ /* The start value to grow halt_poll_ns from */ unsigned int halt_poll_ns_grow_start = 10000; /* 10us */ -module_param(halt_poll_ns_grow_start, uint, 0644); +module_param_cb(halt_poll_ns_grow_start, &grow_start_ops, &halt_poll_ns_grow_start, 0644); EXPORT_SYMBOL_GPL(halt_poll_ns_grow_start); /* Default resets per-vcpu halt_poll_ns . */ From patchwork Wed Nov 6 09:08:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhenzhong Duan X-Patchwork-Id: 11229691 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B5073112B for ; Wed, 6 Nov 2019 09:10:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 91220217F5 for ; Wed, 6 Nov 2019 09:10:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="FDVg98sK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731646AbfKFJKD (ORCPT ); Wed, 6 Nov 2019 04:10:03 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:44116 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731631AbfKFJJ6 (ORCPT ); Wed, 6 Nov 2019 04:09:58 -0500 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 xA698eQS115926; Wed, 6 Nov 2019 09:09:29 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=Z5cM7OxDMmHXMNVS03rtcEV1AuDRRTLHQfvZ7yXT3XA=; b=FDVg98sKQ+FA88I49PM9+wbl1KeVTiawHXqKEwFUfkwHOmgzlR0owvji/PZNjMS0pqV7 mfVCHvEw/DAT0O/riEig/c1TE66A1GyUAO4wdT0leg48S89wPs9ppYo6iLs7Kbr3wC27 ApXcQFzgdO3lh3YHo7BPa2m5Srm74bsVXlnhV7iTPjZFsFcQjzRlP6kOxGCxMyZecGHT iqMd8zJKYUOxNlMvP0nW0YAOoSdJ0hNq7mhCOjfuv79YM3HwOpoZvx9Zd5L80fSOjXE7 HDNjLQLeoka/sX+gJp6QLsVuH9TYaX6oNHJyUM2WnOd0iW6ZMcMIfVfVcli0qR6kyW8Q cA== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2130.oracle.com with ESMTP id 2w117u4gny-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Nov 2019 09:09:29 +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 xA698qnP015260; Wed, 6 Nov 2019 09:09:29 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3020.oracle.com with ESMTP id 2w31631dwc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Nov 2019 09:09:29 +0000 Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id xA699SAk013641; Wed, 6 Nov 2019 09:09:28 GMT Received: from z2.cn.oracle.com (/10.182.71.218) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 06 Nov 2019 01:09:28 -0800 From: Zhenzhong Duan To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: pbonzini@redhat.com, rkrcmar@redhat.com, rafael.j.wysocki@intel.com, joao.m.martins@oracle.com, mtosatti@redhat.com, Zhenzhong Duan Subject: [PATCH v2 3/4] cpuidle-haltpoll: ensure cpu_halt_poll_us in right scope Date: Wed, 6 Nov 2019 17:08:51 +0800 Message-Id: <1573031332-2121-4-git-send-email-zhenzhong.duan@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1573031332-2121-1-git-send-email-zhenzhong.duan@oracle.com> References: <1573031332-2121-1-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=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060096 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=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060096 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org As user can adjust guest_halt_poll_grow_start and guest_halt_poll_ns which leads to cpu_halt_poll_us beyond the two boundaries. This patch ensures cpu_halt_poll_us in that scope. If guest_halt_poll_shrink is 0, shrink the cpu_halt_poll_us to guest_halt_poll_grow_start instead of 0. To disable poll we can set guest_halt_poll_ns to 0. If user wrongly set guest_halt_poll_grow_start > guest_halt_poll_ns > 0, guest_halt_poll_ns take precedency and poll time is a fixed value of guest_halt_poll_ns. Signed-off-by: Zhenzhong Duan --- drivers/cpuidle/governors/haltpoll.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c index 660859d..d0b38b53 100644 --- a/drivers/cpuidle/governors/haltpoll.c +++ b/drivers/cpuidle/governors/haltpoll.c @@ -97,32 +97,30 @@ 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 = dev->poll_limit_ns; u64 block_ns = block_us*NSEC_PER_USEC; /* Grow cpu_halt_poll_us if - * cpu_halt_poll_us < block_ns < guest_halt_poll_us + * cpu_halt_poll_us < block_ns <= guest_halt_poll_us */ - if (block_ns > dev->poll_limit_ns && block_ns <= guest_halt_poll_ns) { + if (block_ns > dev->poll_limit_ns && block_ns <= guest_halt_poll_ns && + guest_halt_poll_grow) val = dev->poll_limit_ns * guest_halt_poll_grow; - - if (val < guest_halt_poll_grow_start) - val = guest_halt_poll_grow_start; - if (val > guest_halt_poll_ns) - val = guest_halt_poll_ns; - - dev->poll_limit_ns = val; - } else if (block_ns > guest_halt_poll_ns && - guest_halt_poll_allow_shrink) { + else if (block_ns > guest_halt_poll_ns && + guest_halt_poll_allow_shrink) { unsigned int shrink = guest_halt_poll_shrink; - val = dev->poll_limit_ns; if (shrink == 0) - val = 0; + val = guest_halt_poll_grow_start; else val /= shrink; - dev->poll_limit_ns = val; } + if (val < guest_halt_poll_grow_start) + val = guest_halt_poll_grow_start; + if (val > guest_halt_poll_ns) + val = guest_halt_poll_ns; + + dev->poll_limit_ns = val; } /** From patchwork Wed Nov 6 09:08:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhenzhong Duan X-Patchwork-Id: 11229689 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6243E112B for ; Wed, 6 Nov 2019 09:10:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F32321848 for ; 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Wed, 06 Nov 2019 09:09:32 +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 xA69867h077683; Wed, 6 Nov 2019 09:09:32 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3030.oracle.com with ESMTP id 2w35pqk3c2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 06 Nov 2019 09:09:31 +0000 Received: from abhmp0009.oracle.com (abhmp0009.oracle.com [141.146.116.15]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id xA699U1x006074; Wed, 6 Nov 2019 09:09:30 GMT Received: from z2.cn.oracle.com (/10.182.71.218) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 06 Nov 2019 01:09:30 -0800 From: Zhenzhong Duan To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: pbonzini@redhat.com, rkrcmar@redhat.com, rafael.j.wysocki@intel.com, joao.m.martins@oracle.com, mtosatti@redhat.com, Zhenzhong Duan Subject: [PATCH v2 4/4] KVM: ensure vCPU halt_poll_us in right scope Date: Wed, 6 Nov 2019 17:08:52 +0800 Message-Id: <1573031332-2121-5-git-send-email-zhenzhong.duan@oracle.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1573031332-2121-1-git-send-email-zhenzhong.duan@oracle.com> References: <1573031332-2121-1-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=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060096 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=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1911060096 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org As user can adjust halt_poll_ns_grow_start and halt_poll_ns which leads to vcpu->halt_poll_ns beyond the two boundaries. This patch ensures vcpu->halt_poll_ns in that scope after growing or shrinking. If halt_poll_ns_shrink is 0, shrink vcpu->halt_poll_ns to halt_poll_ns_grow_start instead of 0. To disable poll we can set halt_poll_ns to 0. In case user wrongly set halt_poll_ns_grow_start > halt_poll_ns > 0, halt_poll_ns take precedency and poll time is a fixed value of halt_poll_ns. This patch also simplifies branch check based on the guest haltpoll code. Signed-off-by: Zhenzhong Duan --- virt/kvm/kvm_main.c | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 359516b..b4fca66 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -2308,9 +2308,15 @@ static void shrink_halt_poll_ns(struct kvm_vcpu *vcpu) old = val = vcpu->halt_poll_ns; shrink = READ_ONCE(halt_poll_ns_shrink); if (shrink == 0) - val = 0; - else + val = halt_poll_ns_grow_start; + else { val /= shrink; + if (val < halt_poll_ns_grow_start) + val = halt_poll_ns_grow_start; + } + + if (val > halt_poll_ns) + val = halt_poll_ns; vcpu->halt_poll_ns = val; trace_kvm_halt_poll_ns_shrink(vcpu->vcpu_id, val, old); @@ -2385,21 +2391,12 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) block_ns = ktime_to_ns(cur) - ktime_to_ns(start); if (!kvm_arch_no_poll(vcpu)) { - if (!vcpu_valid_wakeup(vcpu)) { + /* we had a long block, shrink polling */ + if (!vcpu_valid_wakeup(vcpu) || block_ns > halt_poll_ns) shrink_halt_poll_ns(vcpu); - } else if (halt_poll_ns) { - if (block_ns <= vcpu->halt_poll_ns) - ; - /* we had a long block, shrink polling */ - else if (vcpu->halt_poll_ns && block_ns > halt_poll_ns) - shrink_halt_poll_ns(vcpu); - /* we had a short halt and our poll time is too small */ - else if (vcpu->halt_poll_ns < halt_poll_ns && - block_ns < halt_poll_ns) - grow_halt_poll_ns(vcpu); - } else { - vcpu->halt_poll_ns = 0; - } + /* we had a short block and our poll time is too small */ + else if (block_ns > vcpu->halt_poll_ns) + grow_halt_poll_ns(vcpu); } trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));