From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH] elevator: allow specifying elevator by config boot param for blk-mq devices To: Johannes Thumshirn Cc: Alex Ivanov , linux-block@vger.kernel.org References: <20170712185708.5987-1-yourbestfriend@openmailbox.org> <0661f4cc-a5dc-5747-dd38-de78586843a2@kernel.dk> <20170713101154.GH5212@linux-x5ow.site> <49033d7d-8941-3c17-962f-dab170401bcf@kernel.dk> <20170714064026.GB3484@linux-x5ow.site> From: Jens Axboe Message-ID: <8080a6a6-ccc5-95d8-031b-01a156b2cd65@kernel.dk> Date: Fri, 14 Jul 2017 08:26:52 -0600 MIME-Version: 1.0 In-Reply-To: <20170714064026.GB3484@linux-x5ow.site> Content-Type: text/plain; charset=utf-8 List-ID: On 07/14/2017 12:40 AM, Johannes Thumshirn wrote: > On Thu, Jul 13, 2017 at 08:02:41AM -0600, Jens Axboe wrote: >> Because it sucks as an interface - there's no way to apply different >> settings to different devices, and using the kernel command line to >> control something like this is ugly. It never should have been done. >> >> The sysfs interface, either manually, scripted, or through udev, >> makes a lot more sense. > > Not that I disagree with your reasons, but not being able to select a > mq scheduler confuses quite some users out there. Maybe we can add something about the API being deprecated, if someone tries to select an mq scheduler. The old scheduler will die in due course once that path goes away, and once that happens, we can kill the parameter. -- Jens Axboe