From patchwork Sat Nov 28 14:18:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shenming Lu X-Patchwork-Id: 11937483 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=-16.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 726C0C64E7B for ; Sat, 28 Nov 2020 14:21:05 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 1DE6024686 for ; Sat, 28 Nov 2020 14:21:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="pi9f8GxW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DE6024686 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+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-ID:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=vRH2kj7bivoZwdTYCqPttzIqz2N2ombtjxcjanHRv2E=; b=pi9f8GxW0FIvIhjcUroLGI8JY /cq2WjkjqqIpFtUNdLFOyZsC9NX/LWLLaA9a3t8zbdQPqfb9NqHVbT5RxN+mY+3p+1WD3d+eLMcAy PaYI30nS7KClwL4u7ZrAaOmOfQkvFRIR6xgkmZ8kg21iCeljlH42QCBySRKM7Cd2Fc+zA8uIfLDsI 3S6q3SK/l+M7QrLuvICDxlw+2B1fa+gznAQxEdo/ypxMObZDDCoRZ1kQN+G/LuFnEIR9q1awbhmro ZLaDcfATVM0tSp0tZpKv3ycxGkzXNS8m0uLflgyGlO+Ft+/2C8B7GbnRSvgwpVKTNtulu/faMoFsE bZfEKop3A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kj14o-0005LA-Q2; Sat, 28 Nov 2020 14:19:50 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kj14l-0005KZ-FX for linux-arm-kernel@lists.infradead.org; Sat, 28 Nov 2020 14:19:48 +0000 Received: from DGGEMS403-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Cjtsh1WnPzhj5H; Sat, 28 Nov 2020 22:19:20 +0800 (CST) Received: from DESKTOP-7FEPK9S.china.huawei.com (10.174.187.74) by DGGEMS403-HUB.china.huawei.com (10.3.19.203) with Microsoft SMTP Server id 14.3.487.0; Sat, 28 Nov 2020 22:19:33 +0800 From: Shenming Lu To: Marc Zyngier , Thomas Gleixner , "Jason Cooper" , , , , , James Morse , Julien Thierry , Suzuki K Poulose , Catalin Marinas , Will Deacon , Eric Auger , Christoffer Dall Subject: [PATCH v2 1/2] irqchip/gic-v4.1: Reduce the delay time of the poll on the GICR_VPENDBASER.Dirty bit Date: Sat, 28 Nov 2020 22:18:56 +0800 Message-ID: <20201128141857.983-2-lushenming@huawei.com> X-Mailer: git-send-email 2.27.0.windows.1 In-Reply-To: <20201128141857.983-1-lushenming@huawei.com> References: <20201128141857.983-1-lushenming@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.187.74] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201128_091947_857688_92249CA0 X-CRM114-Status: GOOD ( 11.32 ) 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: yuzenghui@huawei.com, wanghaibin.wang@huawei.com, lushenming@huawei.com Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The 10 delay_us of the poll on the GICR_VPENDBASER.Dirty bit is too high, which might greatly affect the total scheduling latency of a vCPU in our measurement. So we reduce it to 1 to lessen the impact. Signed-off-by: Shenming Lu --- drivers/irqchip/irq-gic-v3-its.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 0fec31931e11..22f427135c6b 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -3809,7 +3809,7 @@ static void its_wait_vpt_parse_complete(void) WARN_ON_ONCE(readq_relaxed_poll_timeout_atomic(vlpi_base + GICR_VPENDBASER, val, !(val & GICR_VPENDBASER_Dirty), - 10, 500)); + 1, 500)); } static void its_vpe_schedule(struct its_vpe *vpe)