From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 2/2] libata: turn off NCQ if queue depth is adjusted to 1 Date: Sat, 16 Dec 2006 12:19:35 -0500 Message-ID: <45842AA7.5060204@pobox.com> References: <20060930104439.GP25800@htj.dyndns.org> <20060930104500.GQ25800@htj.dyndns.org> <20060930180359.GP4163@kernel.dk> <1159649460.13029.145.camel@localhost.localdomain> <20060930202628.GF5670@kernel.dk> <451F0927.2010804@emc.com> <451F0BF7.1000200@gmail.com> <451F1148.5050604@emc.com> <451FBAFC.4040001@emc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:35071 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161239AbWLPRTo (ORCPT ); Sat, 16 Dec 2006 12:19:44 -0500 In-Reply-To: <451FBAFC.4040001@emc.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Ric Wheeler Cc: Tejun Heo , Jens Axboe , Alan Cox , linux-ide@vger.kernel.org Ric Wheeler wrote: > Just thinking out loud, but it would be really helpful to get drive > vendor's a basic set of tests for Linux systems - error handling, > performance, SMART features, etc - that would run natively on linux. > We would need to get something really easy to deploy, like a live CD > image with the test suite that could be booted on a pc, to get into an > environment that is used to booting DOS based floppies... Strongly agreed. I know some people use DOS-based environments; I would prefer the following test environment: Equip systems with NICs that can do wake-on-lan and PXE. To initiate testing of a system, perform a PXE boot, which downloads a custom-compiled kernel and initrd over the net. The kernel boots, sets up a test environment in either ramfs or nfs (or a combination thereof), and runs a "do everything" script which starts the tests specified by the network admin. The tests performed should be in three classes: (1) data and non-data tests performed over a "direct submit" interface like SG_IO, (2) data tests performed by directly accessing the block device, and (3) data tests performed by accessing data through a common filesystem [ext3 or whatever is popular]. It is already trivial to write tests for #2 and #3. Tests in class #1 may require some thought and complexity, such as using multiple threads, to achieve maximal use of command queueing features. I'm not aware of any userspace interface that allows fine-grained control of TCQ (Jens correct me here), or even an interface that does not require multiple threads to submit multiple tasks simultaneously. Jeff