From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: New driver mtipx2xx submission Date: Thu, 12 May 2011 10:39:31 -0400 Message-ID: <4DCBF123.1050607@garzik.org> References: <22A973199D2C2F46933448F6E7990A300204F2BC@ntxboimbx31.micron.com> <20110428230605.78c55c70@lxorguk.ukuu.org.uk> <4DC01907.50009@teksavvy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-yw0-f46.google.com ([209.85.213.46]:43601 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757518Ab1ELOje (ORCPT ); Thu, 12 May 2011 10:39:34 -0400 Received: by ywj3 with SMTP id 3so535337ywj.19 for ; Thu, 12 May 2011 07:39:34 -0700 (PDT) In-Reply-To: <4DC01907.50009@teksavvy.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Mark Lord Cc: Jeff Moyer , Alan Cox , "Asai Thambi Samymuthu Pattrayasamy (asamymuthupa) [CONTRACTOR]" , linux-ide@vger.kernel.org On 05/03/2011 11:02 AM, Mark Lord wrote: > On 11-05-02 02:40 PM, Jeff Moyer wrote: > .. >> Given the highly parallel nature of these parts, I wouldn't be surprised >> if the ahci queue depth of 31 is one of the main bottlenecks. Can you >> think of a way to extend the ahci driver in this manner to accommodate >> devices like this one? > .. > > I imagine that another performance drain might be libata's lack of > support for host controller queues --> a hardware queuing layer that > exists between the host and the drive's own queuing mechanism. What do you feel libata lacks, in this area? AHCI has a host controller queue that it actively manages, and we ship off requests to that queue ASAP. Jeff