From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: SDHCI Regression with 6ce3dd6eec11 ("blk-mq: issue directly if hw queue isn't busy in case of 'none'") To: Ming Lei Cc: Adrian Hunter , linux-block@vger.kernel.org, linux-mmc@vger.kernel.org, Jens Axboe References: <855d68f2-17ed-eaae-2f13-d0ff95b6834f@linux.intel.com> <2f4d5335-15dd-1dea-5d80-36b79455577a@intel.com> <20180821135725.GA28835@ming.t460p> From: Jarkko Nikula Message-ID: <741127be-7d37-695c-15a9-47186959e639@linux.intel.com> Date: Wed, 22 Aug 2018 09:06:40 +0300 MIME-Version: 1.0 In-Reply-To: <20180821135725.GA28835@ming.t460p> Content-Type: text/plain; charset=utf-8; format=flowed List-ID: On 08/21/2018 04:57 PM, Ming Lei wrote: > On Tue, Aug 21, 2018 at 04:45:41PM +0300, Jarkko Nikula wrote: >> On 08/21/2018 04:03 PM, Adrian Hunter wrote: >>> On 21/08/18 15:37, Jarkko Nikula wrote: >>>> Hi >>>> >>>> I bisected some kind of SDHCI regression to commit 6ce3dd6eec11 ("blk-mq: >>>> issue directly if hw queue isn't busy in case of 'none'") causing dumps >>>> below and one or more systemd-udevd processes being in uninterruptible sleep >>>> state preventing safe reboot/shutdown. >>>> >>>> This is from an Intel Baytrail based tablet with integrated eMMC but my >>>> up-to-date Debian/testing rootfs (with systemd) is on USB stick. >>>> >>>> It doesn't revert cleanly on today's head 778a33959a8a but issue is gone if >>>> I go to a commit before 6ce3dd6eec11 and occurs at 6ce3dd6eec11. >>> >>> This was discussed here: >>> >>> https://marc.info/?l=linux-block&m=153334717506073&w=2 >>> >>> Coincidentally, I just sent the fix patch: >>> >>> https://marc.info/?l=linux-mmc&m=153485326025301&w=2 >>> >> Cool, it fixed my regression. I tested both on top of 6ce3dd6eec11 and head >> 778a33959a8a. Maybe you would like to add into your patch another fixes tag >> and my tested by: >> >> Fixes: 6ce3dd6eec11 ("blk-mq: issue directly if hw queue isn't busy in case >> of 'none'") > > If you read the above links carefully, you'd see it is wrong to add the tag of > 'Fixes: 6ce3dd6eec11'. > Hmm... why? That commit 6ce3dd6eec11 was clearly regressing on my setup while Adrian's fix for 81196976ed94 that has been present since v4.16 fixes my finding too. I don't know well enough MMC and block layer but if commit 6ce3dd6eec11 revealed an issue from MMC under my configuration I'd call it still a regression. -- Jarkko