From patchwork Mon Oct 21 10:52:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yunfeng Ye X-Patchwork-Id: 11201887 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 782C7139A for ; Mon, 21 Oct 2019 10:52:54 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 55DDB2084C for ; Mon, 21 Oct 2019 10:52:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="q+Hwo1Ng" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 55DDB2084C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Date:Message-ID:Subject: From:To:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=9g7XdKfGUtRMLllu28LXFx4Rd8v2pQBOupmYaZh97kk=; b=q+Hwo1NgCaBTkd o/3m8QYT0h5Jv+K65ExX6Se11sAXTEyC3Q4Jqqws0yOe/SVWZdrzEnPQlO6XIrD8yko6ytJSxDPlw +lVTBE948BzfmwJOmx3NlA9crTiSUGSj0RTfqUQadJ9iwgd63crIcFd9VCnXKci/hy3vNA0jazuVi FQ9FzCu3XloB0IaambumQt0aXfOCBejdhNiykLefa7SL3Qkbyx0QqHu6jLIqgaNavTFijXs8UMkvJ gX3R7Fl3Z9dw2UaSNWUhiymAZttyG4Oc3te5Ltgy2qU059KXgbQ/nC18w2lE/AQ7jEg6n48/04xo8 NMJUTD2HX9fs2UvWIbpg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iMVIz-0005tB-Pg; Mon, 21 Oct 2019 10:52:53 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191] helo=huawei.com) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iMVIw-0005s1-Vw for linux-arm-kernel@lists.infradead.org; Mon, 21 Oct 2019 10:52:52 +0000 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 7B0CC45A7532B2973BD4; Mon, 21 Oct 2019 18:52:43 +0800 (CST) Received: from [127.0.0.1] (10.177.251.225) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.439.0; Mon, 21 Oct 2019 18:52:36 +0800 To: , , , , , , , , , From: Yunfeng Ye Subject: [PATCH v5] arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill() Message-ID: <710429cc-4d88-b7c3-b068-5459cf8133b5@huawei.com> Date: Mon, 21 Oct 2019 18:52:16 +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-Language: en-US X-Originating-IP: [10.177.251.225] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191021_035251_220292_C7422AA1 X-CRM114-Status: GOOD ( 14.67 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [45.249.212.191 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: hushiyuan@huawei.com, linfeilong@huawei.com, wuyun.wu@huawei.com, "linux-kernel@vger.kernel.org" , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org In cases like suspend-to-disk and suspend-to-ram, a large number of CPU cores need to be shut down. At present, the CPU hotplug operation is serialised, and the CPU cores can only be shut down one by one. In this process, if PSCI affinity_info() does not return LEVEL_OFF quickly, cpu_psci_cpu_kill() needs to wait for 10ms. If hundreds of CPU cores need to be shut down, it will take a long time. Normally, there is no need to wait 10ms in cpu_psci_cpu_kill(). So change the wait interval from 10 ms to max 1 ms and use usleep_range() instead of msleep() for more accurate timer. In addition, reducing the time interval will increase the messages output, so remove the "Retry ..." message, instead, track time and output to the the sucessful message. Signed-off-by: Yunfeng Ye Reviewed-by: Sudeep Holla --- v4 -> v5: - track time instead of loop counter v3 -> v4: - using time_before(jiffies, timeout) to check - update the comment as review suggest v2 -> v3: - update the comment - remove the busy-wait logic, modify the loop logic and output message v1 -> v2: - use usleep_range() instead of udelay() after waiting for a while arch/arm64/kernel/psci.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index c9f72b2665f1..43ae4e0c968f 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -81,7 +81,8 @@ static void cpu_psci_cpu_die(unsigned int cpu) static int cpu_psci_cpu_kill(unsigned int cpu) { - int err, i; + int err; + unsigned long start, end; if (!psci_ops.affinity_info) return 0; @@ -91,16 +92,18 @@ 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++) { + start = jiffies; + end = start + 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); + pr_info("CPU%d killed (polled %d ms)\n", cpu, + jiffies_to_msecs(jiffies - start)); return 0; } - msleep(10); - pr_info("Retrying again to check for CPU kill\n"); - } + usleep_range(100, 1000); + } while (time_before(jiffies, end)); pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n", cpu, err);