From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757818AbZF2Mpe (ORCPT ); Mon, 29 Jun 2009 08:45:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752373AbZF2MpS (ORCPT ); Mon, 29 Jun 2009 08:45:18 -0400 Received: from ip67-152-220-66.z220-152-67.customer.algx.net ([67.152.220.66]:5211 "EHLO daytona.int.panasas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751894AbZF2MpR (ORCPT ); Mon, 29 Jun 2009 08:45:17 -0400 Message-ID: <4A48B75C.5080209@panasas.com> Date: Mon, 29 Jun 2009 15:45:16 +0300 From: Boaz Harrosh User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1b3pre) Gecko/20090315 Remi/3.0-0.b2.fc10.remi Thunderbird/3.0b2 MIME-Version: 1.0 To: Jens Axboe CC: NeilBrown , "Martin K. Petersen" , Mike Snitzer , Linus Torvalds , Alasdair G Kergon , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-ide@vger.kernel.org, linux-fsdevel@vger.kernel.org, device-mapper development Subject: Re: [dm-devel] REQUEST for new 'topology' metrics to be moved out of the 'queue' sysfs directory. References: <125b48b7ffc99a496fbdd512f38cada5.squirrel@neil.brown.name> <20090625194015.GB31415@kernel.dk> <19012.49673.454853.975682@notabene.brown> <20090626125037.GO23611@kernel.dk> <20090626132940.GR23611@kernel.dk> <19014.4447.248248.63960@notabene.brown> <20090629101841.GF23611@kernel.dk> <20090629114121.GH23611@kernel.dk> In-Reply-To: <20090629114121.GH23611@kernel.dk> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 29 Jun 2009 12:45:20.0350 (UTC) FILETIME=[7641D7E0:01C9F8B7] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/29/2009 02:41 PM, Jens Axboe wrote: > On Mon, Jun 29 2009, NeilBrown wrote: >> On Mon, June 29, 2009 8:18 pm, Jens Axboe wrote: >>> On Sat, Jun 27 2009, Neil Brown wrote: >>>>> There's no such thing as first or second class block devices. The fact >>>>> that drivers using ->make_request_fn directly do not utilize the full >>>>> scope of the queue isn't a very interesting fact, imho. >>>> Your phrase "drivers using ->make_request_fn directly" seems to >>>> suggest you are looking at things very differently to me. >>>> >>>> From my perspective, all drivers use ->make_request_fn equally. >>>> Some set it to "__make_request", some to "md_make_request", others to >>>> "dm_request" or "loop_make_request" etc. >>> Neil, will you please stop these silly games. Stop trying to invent >>> differences based on interpretations of what you read into my replies. >> >> We do seem to be having trouble communicating don't we :-( >> Be assured that it is not my intention to play games, silly or otherwise. >> >> Maybe I should just try sending you patches. Maybe that will >> make my meaning clearer. >> >> For the moment, I'm much more interested in the other question, >> that of whether I can avoid having a 'queue' directory introduced into >> md/dm/etc device directories in sysfs. > > We already talked about this, several times. My answer is that it seems > pointless to begin with internally, and externally it just makes the API > worse since tools then have to know which device type they are talking > to. > I do however see a problem with sysfs-files that mostly work for most devices but for some "device type" they do nothing silently. At least make these directory/files read-only for the un-used cases (eg. dm/md). And return proper values to indicate their un-usefulness like "-1" or "NA" > So I still see absolutely zero point in making such a change, quite the > opposite. > Just my $0.017 Boaz