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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id A3977C44501 for ; Wed, 21 Jan 2026 08:53:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Tae9U7McvW0hfPoFDeOkrv1yDXDhuBS782pMRzhzkVk=; b=4UQlnS8guJEXA8EubCHLEaBfgF bakCi7KtRZSyYnAlO4BF/7kQMwqAm6rqMWdQoxaTXn8gPPGrPQlgctCFdyqxwZCS5UciDH4eTqAXi 0jYaohLdT4NeK/ccKpwS6hAYdKJLlMY+FKwYoN7NSn9ZKOwfq87eX8yEGM3hC/DAk0DHFP5KRe2gw BgcWciy4oxeNopDWtpdwISPFnwuiVg2y2eB+fFTXyeCQTufB8VXof5UkgBzYjD3KoFXvu6H7+JKx6 7Ht/eit/YlgFJtqo5BtsFTPzdq4ObHmJ7eA3sj8CblvWjM5d9MELQ5Gq8JiIzF5UoHjnvzr0Q49Ts AhMHPrmw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1viTxz-000000058A7-1ONG; Wed, 21 Jan 2026 08:53:31 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1viTxv-0000000588q-2KuO for linux-nvme@lists.infradead.org; Wed, 21 Jan 2026 08:53:29 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1768985604; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Tae9U7McvW0hfPoFDeOkrv1yDXDhuBS782pMRzhzkVk=; b=Wb6C1+/I1YCMELiH2ww+GRPiQKU4nNmKUV+NpS7XvjBd7smm3QZubtVlTBKnxFBg+19hEY Fi1lenI8AaOEge7y3Dye5lLowT+bHCcBhkiQSScHO37NdAd4DA628RHdYzgjG1WSm6fwOU h6rkKWjUoC3dtzWfi/CGX0fmBcth478= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-465-z_KCQ28HOmKlPseQwUEmZg-1; Wed, 21 Jan 2026 03:53:22 -0500 X-MC-Unique: z_KCQ28HOmKlPseQwUEmZg-1 X-Mimecast-MFC-AGG-ID: z_KCQ28HOmKlPseQwUEmZg_1768985601 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6F17719560AE; Wed, 21 Jan 2026 08:53:21 +0000 (UTC) Received: from fedora (unknown [10.72.116.62]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CDF9219560B2; Wed, 21 Jan 2026 08:53:15 +0000 (UTC) Date: Wed, 21 Jan 2026 16:53:10 +0800 From: Ming Lei To: Yi Zhang Cc: linux-block , "open list:NVM EXPRESS DRIVER" , Shinichiro Kawasaki , Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni Subject: Re: [bug report] nvme-tcp poll queue causes busy loop and 100% CPU in nvme_tcp_poll() on the latest linux-block/for-next Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260121_005327_665612_1AB33BFD X-CRM114-Status: GOOD ( 12.59 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Jan 21, 2026 at 10:50:00AM +0800, Yi Zhang wrote: > Hi > > This issue was observed on the latest linux-block/for-next during CKI > test, where enabling the poll queues leads to a tight busy polling > loop and 100% CPU usage during "nvme connect". > It seems was introduced from v6.19-rc1 and cannot reproduced on v6.18. > I will try to bisect it. It may be related with f22ecf9c14c1 ("blk-mq: delete task running check in blk_hctx_poll()"). I guess it only happens when `nvme connect` takes a bit long time, not sure if it can be reproduced 100%. Thanks, Ming