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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 3916EC10F11 for ; Wed, 24 Apr 2019 20:13:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E5CE72175B for ; Wed, 24 Apr 2019 20:13:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556136790; bh=WYh+kk/1twNMT0mmd6W48OSv9HDGzbHgY45yeOjOBqQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=DZZEuqCjpI0FJEtBFHEHk13QovnHzADuCpFvnz2CunUgsEtvJP0ENyfhLQ0kWQGJY 9NDyB5rnBcJA625/JSgnp0kfCY/J29RZdXOQaV2xbY592LFNRc8yKjeeT7AcQWVTA9 cZ7TthCyeAAnEsFAaF6znuvxZqZrndQB/rFPM7Vo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727751AbfDXUNI (ORCPT ); Wed, 24 Apr 2019 16:13:08 -0400 Received: from mga03.intel.com ([134.134.136.65]:56592 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726004AbfDXUNI (ORCPT ); Wed, 24 Apr 2019 16:13:08 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Apr 2019 13:13:07 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,390,1549958400"; d="scan'208";a="167600792" Received: from unknown (HELO localhost.localdomain) ([10.232.112.69]) by fmsmga001.fm.intel.com with ESMTP; 24 Apr 2019 13:13:07 -0700 Date: Wed, 24 Apr 2019 14:07:06 -0600 From: Keith Busch To: Sagi Grimberg Cc: Maximilian Heyne , David Woodhouse , Amit Shah , Keith Busch , Jens Axboe , Christoph Hellwig , James Smart , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 0/2] Adding per-controller timeout support to nvme Message-ID: <20190424200706.GB15412@localhost.localdomain> References: <20190403123506.122904-1-mheyne@amazon.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 24, 2019 at 09:55:16AM -0700, Sagi Grimberg wrote: > > > As different nvme controllers are connect via different fabrics, some require > > different timeout settings than others. This series implements per-controller > > timeouts in the nvme subsystem which can be set via sysfs. > > How much of a real issue is this? > > block io_timeout defaults to 30 seconds which are considered a universal > eternity for pretty much any nvme fabric. Moreover, io_timeout is > mutable already on a per-namespace level. > > This leaves the admin_timeout which goes beyond this to 60 seconds... > > Can you describe what exactly are you trying to solve? I think they must have an nvme target that is backed by slow media (i.e. non-SSD). If that's the case, I think it may be a better option if the target advertises relatively shallow queue depths and/or lower MDTS that better aligns to the backing storage capabilies.