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 3B10FCD37B5 for ; Mon, 11 May 2026 08:52:38 +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:References:To: From:Subject:Cc:Message-Id:Date:Content-Type:Content-Transfer-Encoding: Mime-Version:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=b3MA5PvIuwDpJghEkiB/TtaipFcoq0HCWN82l2B+X78=; b=S2Lu5HX/LAXswmTb4S0YgDQTVl YNuAXNbFrNYDTzJL7VAStcPF4uDdC8izxAGmTDf3PpZmF66e2BI3qB0HWawDAapa0uJ5wDSNEkHGH L+ebNmVAKyHCWmEtlXEb+cYDNrcjcd85Ph162u83f9GRgHrI+0zD6WydySYWBtBh0FvCylI+m6ayg zd1lmxRIIvRxdt4zzN8OLE8olQSwpTw9tt2/onfa2Kccv4Dz6EPSuVfaGRLMxzj1m7w30GhLE3TNy /uWZojIJ7GDhdor2PfJcLPw7YCVAjnV0o29yTfGBcsNx58U0i/rGNv+pOXSWTDdM709m549MPUknT qImeMaZA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wMMNO-0000000Cnmg-2Nn8; Mon, 11 May 2026 08:52:34 +0000 Received: from 128-116-240-228.dyn.eolo.it ([128.116.240.228] helo=arkamax.eu) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wMMNK-0000000Cnlt-2TXO for linux-nvme@lists.infradead.org; Mon, 11 May 2026 08:52:33 +0000 Received: from localhost (128-116-240-228.dyn.eolo.it [128.116.240.228]) by arkamax.eu (OpenSMTPD) with ESMTPSA id 8080efe3 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Mon, 11 May 2026 10:52:25 +0200 (CEST) Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 11 May 2026 10:52:24 +0200 Message-Id: Cc: , , , , , , , , , Subject: Re: [PATCH V4 5/9] nvme: add sysfs attribute to change IO timeout per controller From: "Maurizio Lombardi" To: "Sagi Grimberg" , "Maurizio Lombardi" , X-Mailer: aerc 0.21.0 References: <20260508133335.98612-1-mlombard@redhat.com> <20260508133335.98612-6-mlombard@redhat.com> <86fd8b31-7264-48d1-99e6-a053ae6cae4e@grimberg.me> In-Reply-To: <86fd8b31-7264-48d1-99e6-a053ae6cae4e@grimberg.me> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260511_015231_182343_8153750D X-CRM114-Status: UNSURE ( 8.49 ) X-CRM114-Notice: Please train this message. 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 Mon May 11, 2026 at 12:12 AM CEST, Sagi Grimberg wrote: > > > On 08/05/2026 16:33, Maurizio Lombardi wrote: >> Currently, there is no method to adjust the timeout values on a >> per controller basis with nvme I/O queues. >> Add an io_timeout attribute to nvme so that different nvme controllers >> which may have different timeout requirements can have custom >> I/O timeouts set. > > Why is this needed? Why not simply change the timeout on > the namespaces themselves? One reason is convenience, having an io_timeout default value at the controller level means that a newly discovered or hot-plugged namespace will automatically inherit the controller-specific timeout. Additionally, for nvmeof, the controller allocates a dedicated I/O queue (ctrl->connect_q) that doesn't have a block device representation. The io_timeout attribute will allow userspace to change the timeout for this internal queue. Maurizio