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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 EA159ECE58E for ; Thu, 17 Oct 2019 14:20:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0D182089C for ; Thu, 17 Oct 2019 14:20:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2440087AbfJQOUl (ORCPT ); Thu, 17 Oct 2019 10:20:41 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:4216 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2440048AbfJQOUk (ORCPT ); Thu, 17 Oct 2019 10:20:40 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 5444352314939BFFAD81; Thu, 17 Oct 2019 22:20:29 +0800 (CST) Received: from [127.0.0.1] (10.177.251.225) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.439.0; Thu, 17 Oct 2019 22:20:23 +0800 Subject: Re: [PATCH V2] arm64: psci: Reduce waiting time of cpu_psci_cpu_kill() To: David Laight , Sudeep Holla CC: "catalin.marinas@arm.com" , "will@kernel.org" , "kstewart@linuxfoundation.org" , "gregkh@linuxfoundation.org" , "ard.biesheuvel@linaro.org" , "tglx@linutronix.de" , "wuyun.wu@huawei.com" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "hushiyuan@huawei.com" , "linfeilong@huawei.com" References: <18068756-0f39-6388-3290-cf03746e767d@huawei.com> <9df267db-e647-a81d-16bb-b8bfb06c2624@huawei.com> <20191016153221.GA8978@bogus> <0f550044-9ed2-5f72-1335-73417678ba45@huawei.com> From: Yunfeng Ye Message-ID: <1cd555f0-4074-36b7-8426-6f01130051d2@huawei.com> Date: Thu, 17 Oct 2019 22:19:54 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: 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 On 2019/10/17 22:00, David Laight wrote: > From: Yunfeng Ye >> Sent: 17 October 2019 14:26 > ... >>>> - 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"); >>> >>> You dropped this message, any particular reason ? >>> >> When reduce the time interval to 1ms, the print message maybe increase 10 times. >> on the other hand, cpu_psci_cpu_kill() will print message on success or failure, which >> this retry log is not very necessary. of cource, I think use pr_info_once() instead of >> pr_info() is better. > > Maybe you should print in on (say) the 10th time around the loop. > Can it like this: pr_info("CPU%d killed with %d loops.\n", cpu, loops); If put the number of waiting times in the successful printing message, it is not necessary to print the "Retrying ..." message. thanks. > David > > - > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK > Registration No: 1397386 (Wales) >