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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 6BF75C43331 for ; Fri, 6 Sep 2019 22:35:08 +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 3C02A2082C for ; Fri, 6 Sep 2019 22:35:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QOVOS9qH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C02A2082C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.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:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0WCuXkb+7m/XsAcpieQ6SjzipF2UeASeQhnlEZ33ybE=; b=QOVOS9qH2jbT+E hkhkYnsEejS3keINryorzV+3AhYU85ofMoRPsmvs9z/yU0Sq8mW+11XKFOTzvB2d7NV51C/5NZwvg elCfa8hMHC5i8f3E5e8tH4dJ9/MbfpsDt95whfcpF85Upw+H8dPS581ZBvlaZUJWsfRIM29SaUahc RW29BmlY5DvgzBUyV0pDjQMRuqT0qzcuur6xvzdq0U5M7s4ekxMZtNGf23/7YCZAq6EQsJ2kctukt 7ce+HmhkoXe+59YiCjsOMCBmiizatMD5tlBUmZweKcWR4HBn9lqQ/s+p7GA4ZVQ0SuHfxH8Iikv18 mMk1UF7X33c+2NiJZAJw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i6Mon-00033X-Mr; Fri, 06 Sep 2019 22:35:01 +0000 Received: from mga05.intel.com ([192.55.52.43]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i6Mol-00031c-ET for linux-nvme@lists.infradead.org; Fri, 06 Sep 2019 22:35:00 +0000 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Sep 2019 15:34:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,474,1559545200"; d="scan'208";a="190955919" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by FMSMGA003.fm.intel.com with ESMTP; 06 Sep 2019 15:34:55 -0700 Date: Fri, 6 Sep 2019 16:25:55 -0600 From: Keith Busch To: Ming Lei Subject: Re: [PATCH 1/4] softirq: implement IRQ flood detection mechanism Message-ID: <20190906222555.GB4260@localhost.localdomain> References: <20190903072848.GA22170@ming.t460p> <6f3b6557-1767-8c80-f786-1ea667179b39@acm.org> <2a8bd278-5384-d82f-c09b-4fce236d2d95@linaro.org> <20190905090617.GB4432@ming.t460p> <6a36ccc7-24cd-1d92-fef1-2c5e0f798c36@linaro.org> <20190906014819.GB27116@ming.t460p> <20190906141858.GA3953@localhost.localdomain> <20190906221920.GA12290@ming.t460p> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190906221920.GA12290@ming.t460p> User-Agent: Mutt/1.9.1 (2017-09-22) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190906_153459_499952_E509F299 X-CRM114-Status: GOOD ( 11.76 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jens Axboe , Hannes Reinecke , John Garry , Bart Van Assche , "linux-scsi@vger.kernel.org" , Peter Zijlstra , Long Li , Daniel Lezcano , LKML , "linux-nvme@lists.infradead.org" , Keith Busch , Ingo Molnar , Thomas Gleixner , Christoph Hellwig , Sagi Grimberg Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Sat, Sep 07, 2019 at 06:19:21AM +0800, Ming Lei wrote: > On Fri, Sep 06, 2019 at 05:50:49PM +0000, Long Li wrote: > > >Subject: Re: [PATCH 1/4] softirq: implement IRQ flood detection mechanism > > > > > >Why are all 8 nvmes sharing the same CPU for interrupt handling? > > >Shouldn't matrix_find_best_cpu_managed() handle selecting the least used > > >CPU from the cpumask for the effective interrupt handling? > > > > The tests run on 10 NVMe disks on a system of 80 CPUs. Each NVMe disk has 32 hardware queues. > > Then there are total 320 NVMe MSI/X vectors, and 80 CPUs, so irq matrix > can't avoid effective CPUs overlapping at all. Sure, but it's at most half, meanwhile the CPU that's dispatching requests would naturally be throttled by the other half who's completions are interrupting that CPU, no? _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme