From mboxrd@z Thu Jan 1 00:00:00 1970 From: kylin Subject: Re: PCI express equipment Date: Thu, 5 May 2005 00:28:17 +0800 Message-ID: <87ab37ab05050409283d26dcab@mail.gmail.com> References: <87ab37ab05050404516a2bcc40@mail.gmail.com> <20050504121420.GH19678@parcelfarce.linux.theplanet.co.uk> Reply-To: kylin Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from zproxy.gmail.com ([64.233.162.206]:64313 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S261913AbVEDQ2S convert rfc822-to-8bit (ORCPT ); Wed, 4 May 2005 12:28:18 -0400 Received: by zproxy.gmail.com with SMTP id 18so360364nzp for ; Wed, 04 May 2005 09:28:18 -0700 (PDT) In-Reply-To: <20050504121420.GH19678@parcelfarce.linux.theplanet.co.uk> Content-Disposition: inline Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Matthew Wilcox Cc: linux-scsi@vger.kernel.org On 5/4/05, Matthew Wilcox wrote: > On Wed, May 04, 2005 at 07:51:12PM +0800, kylin wrote: > > On one hand ,hardwarely,as it is always said, PCIE provides the > > superexcellent performance > > > > comparing with the PCI and PCI -X > > On the other ,softwarely,in most the application scenarios i have met > > , the PCIE equipment will > > > > have to use the pci-compatible driver first in linux. > > because the Configuration head is pci compatible in the first 256 byte , > > it is allowed and really works. > > i know if we use the conventional Device Driver for pcie equipment, > > the advanced option such as MSI ,Flow Control ,TC ,VC and hotplug are > > rubbish. MSI and Hotplug are independent of PCI Express and are used > by conventional PCI drivers today. Flow control, TC and VC are all part > of the same thing. sorry for my innocence,but all i want to say here is if the unMSI and unHotplug device driver would influence the normal speed in ONE common scenarios > > unavailable, i also know > > > > that the speed is mainly the problem of Bandwidth and Clocking. Still > > i know that the Trafic > > > > control mechanism is good for the arbitration and thus improve the > > performance just like the > > > > TCP protocol ways. > > Um, no, not really. There's very little hardware support for VC/TC at the > moment, so having software support for it isn't a priority. yeah ,even the bios will rarely support this > In addition, > it really depends how deep your PCI bus hierarchy is whether VC/TC will > have any effect on performance at all. have you seen the E7520 chipset ,sir? > Why is this question on linux-scsi anyway? because myu SCSI interface is connecting to the pcie bus:),love it and love the dog :) -- we who r about to die,salute u!