From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 0/2][RFC] block: default to deadline for SMR devices To: Jeff Moyer , Damien.LeMoal@wdc.com, linux-block@vger.kernel.org Cc: bgurney@redhat.com References: <20180525211432.20359-1-jmoyer@redhat.com> From: Jens Axboe Message-ID: <9756f816-cea7-52cc-e616-54cd7b7d8c75@kernel.dk> Date: Fri, 25 May 2018 16:04:09 -0600 MIME-Version: 1.0 In-Reply-To: <20180525211432.20359-1-jmoyer@redhat.com> Content-Type: text/plain; charset=utf-8 List-ID: On 5/25/18 3:14 PM, Jeff Moyer wrote: > Bryan Gurney reported I/O errors when using dm-zoned with a host-managed > SMR device. It turns out he was using CFQ, which is the default. > Unfortunately, as of v4.16, only the deadline schedulers work well with > host-managed SMR devices. This series aatempts to switch the elevator > to deadline for those devices. > > NOTE: I'm not super happy with setting up one iosched and then > immediately tearing it down. I'm open to suggestions on better ways > to accomplish this goal. Let's please not do this, a few years ago I finally managed to kill drivers changing the scheduler manually. Why can't this go into a udev (or similar) rule? That's where it belongs, imho. -- Jens Axboe