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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 07342C49ED7 for ; Sat, 21 Sep 2019 11:21:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D10B72086A for ; Sat, 21 Sep 2019 11:21:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437781AbfIULVd (ORCPT ); Sat, 21 Sep 2019 07:21:33 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:41716 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2407437AbfIULVd (ORCPT ); Sat, 21 Sep 2019 07:21:33 -0400 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id CDF62BE18E877A097D69; Sat, 21 Sep 2019 19:21:31 +0800 (CST) Received: from [127.0.0.1] (10.177.251.225) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.439.0; Sat, 21 Sep 2019 19:21:23 +0800 To: David Laight , "catalin.marinas@arm.com" , "will@kernel.org" , "kstewart@linuxfoundation.org" , "gregkh@linuxfoundation.org" , "ard.biesheuvel@linaro.org" , "tglx@linutronix.de" CC: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "wuyun.wu@huawei.com" From: Yunfeng Ye Subject: [PATCH V2] arm64: psci: Reduce waiting time of cpu_psci_cpu_kill() Message-ID: <18068756-0f39-6388-3290-cf03746e767d@huawei.com> Date: Sat, 21 Sep 2019 19:21:17 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.251.225] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If psci_ops.affinity_info() fails, it will sleep 10ms, which will not take so long in the right case. Use usleep_range() instead of msleep(), reduce the waiting time, and give a chance to busy wait before sleep. Signed-off-by: Yunfeng Ye --- V1->V2: - use usleep_range() instead of udelay() after waiting for a while arch/arm64/kernel/psci.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index c9f72b2..99b3122 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -82,6 +82,7 @@ static void cpu_psci_cpu_die(unsigned int cpu) static int cpu_psci_cpu_kill(unsigned int cpu) { int err, i; + unsigned long timeout; if (!psci_ops.affinity_info) return 0; @@ -91,16 +92,24 @@ static int cpu_psci_cpu_kill(unsigned int cpu) * while it is dying. So, try again a few times. */ - for (i = 0; i < 10; i++) { + i = 0; + timeout = jiffies + msecs_to_jiffies(100); + do { err = psci_ops.affinity_info(cpu_logical_map(cpu), 0); if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) { pr_info("CPU%d killed.\n", cpu); return 0; } - msleep(10); - pr_info("Retrying again to check for CPU kill\n"); - } + /* busy-wait max 1ms */ + if (i++ < 100) { + cond_resched(); + udelay(10); + continue; + } + + usleep_range(100, 1000); + } while (time_before(jiffies, timeout)); pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n", cpu, err); -- 2.7.4.huawei.3