From patchwork Sat Sep 21 11:21:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yunfeng Ye X-Patchwork-Id: 11155443 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 B9AD314E5 for ; Sat, 21 Sep 2019 11:21:47 +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 8D0E021835 for ; Sat, 21 Sep 2019 11:21:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="f1PWumWF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D0E021835 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=65u09tV6Nfhd3Aa7yPWBy2MTYk7ioslqBxwuWX7lyec=; b=f1PWumWFkwqem/ XyEeHm+GxNf1FfkIHyqqg+IxzMvg/rsxH0AQ+xY3vu+ljn/Iane+FEcvxpg3MGMkoWRYBA4BVneTU ufFVzh1ojpj3CoN4Al+e2nws5p2s7/FRcqjiL8KRwfjwmOVVLDXIfoCv2kwTT0OnryvuqAqQFIU3c 1XIC+h7qDPgCXTT9lDdQg9TouJv3eefFLtOEP8yD+ERUhOwLhAqwJXc3sRzAiBIcob/4sJBgkBnFW COCzZNsNq3XVsk53UzytxIf6GavWz1Vh3mGtL6GTcE8hYvrjuqV5vyYGHqKoFGdgpbCWIBEaOgLlz Atmc/nm9Gn66f83By4vg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iBdSR-0004Oa-Mw; Sat, 21 Sep 2019 11:21:43 +0000 Received: from szxga06-in.huawei.com ([45.249.212.32] helo=huawei.com) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iBdSN-0004Np-O3 for linux-arm-kernel@lists.infradead.org; Sat, 21 Sep 2019 11:21:41 +0000 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" 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-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-20190921_042139_947143_E47A6C9C X-CRM114-Status: GOOD ( 13.95 ) 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 ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [45.249.212.32 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -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: "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 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);