Re: [PATCH 5.13 000/800] 5.13.2-rc1 review

From: Greg Kroah-Hartman
Date: Wed Jul 14 2021 - 09:31:17 EST


On Wed, Jul 14, 2021 at 01:26:26PM +0000, Holger Kiehl wrote:
> On Wed, 14 Jul 2021, Holger Kiehl wrote:
>
> > On Wed, 14 Jul 2021, Greg Kroah-Hartman wrote:
> >
> > > On Wed, Jul 14, 2021 at 05:39:43AM +0000, Holger Kiehl wrote:
> > > > Hello,
> > > >
> > > > On Mon, 12 Jul 2021, Greg Kroah-Hartman wrote:
> > > >
> > > > > This is the start of the stable review cycle for the 5.13.2 release.
> > > > > There are 800 patches in this series, all will be posted as a response
> > > > > to this one. If anyone has any issues with these being applied, please
> > > > > let me know.
> > > > >
> > > > > Responses should be made by Wed, 14 Jul 2021 06:02:46 +0000.
> > > > > Anything received after that time might be too late.
> > > > >
> > > > With this my system no longer boots:
> > > >
> > > > [ OK ] Reached target Swap.
> > > > [ 75.213852] NMI watchdog: Watchdog detected hard LOCKUP on cpu 0
> > > > [ 75.213926] NMI watchdog: Watchdog detected hard LOCKUP on cpu 2
> > > > [ 75.213962] NMI watchdog: Watchdog detected hard LOCKUP on cpu 4
> > > > [FAILED] Failed to start Wait for udev To Complete Device Initialization.
> > > > See 'systemctl status systemd-udev-settle.service' for details.
> > > > Starting Activation of DM RAID sets...
> > > > [ ] (1 of 2) A start job is running for Activation of DM RAID sets (..min ..s / no limit)
> > > > [ ] (2 of 2) A start job is running for Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progress polling (..min ..s / no limit)
> > > >
> > > > System is a Fedora 34 with all updates applied. Two other similar
> > > > systems with AMD CPUs (Ryzen 4750G + 3400G) this does not happen
> > > > and boots fine. The system where it does not boot has an Intel
> > > > Xeon E3-1285L v4 CPU. All of them use a dm_crypt root filesystem.
> > > >
> > > > Any idea which patch I should drop to see if it boots again. I already
> > > > dropped
> > > >
> > > > [PATCH 5.13 743/800] ASoC: Intel: sof_sdw: add quirk support for Brya and BT-offload
> > > >
> > > > and I just see that this one should also be dropped:
> > > >
> > > > [PATCH 5.13 768/800] hugetlb: address ref count racing in prep_compound_gigantic_page
> > > >
> > > > Will still need to test this.
> > >
> > > Can you run 'git bisect' to see what commit causes the problem?
> > >
> > Yes, will try to do that. I think it will take some time ...
> >
> With the help of Pavel Machek and Jiri Slaby I was able 'git bisect'
> this to:
>
> yoda:/usr/src/kernels/linux-5.13.y# git bisect good
> a483f513670541227e6a31ac7141826b8c785842 is the first bad commit
> commit a483f513670541227e6a31ac7141826b8c785842
> Author: Jan Kara <jack@xxxxxxx>
> Date: Wed Jun 23 11:36:33 2021 +0200
>
> bfq: Remove merged request already in bfq_requests_merged()
>
> [ Upstream commit a921c655f2033dd1ce1379128efe881dda23ea37 ]
>
> Currently, bfq does very little in bfq_requests_merged() and handles all
> the request cleanup in bfq_finish_requeue_request() called from
> blk_mq_free_request(). That is currently safe only because
> blk_mq_free_request() is called shortly after bfq_requests_merged()
> while bfqd->lock is still held. However to fix a lock inversion between
> bfqd->lock and ioc->lock, we need to call blk_mq_free_request() after
> dropping bfqd->lock. That would mean that already merged request could
> be seen by other processes inside bfq queues and possibly dispatched to
> the device which is wrong. So move cleanup of the request from
> bfq_finish_requeue_request() to bfq_requests_merged().
>
> Acked-by: Paolo Valente <paolo.valente@xxxxxxxxxx>
> Signed-off-by: Jan Kara <jack@xxxxxxx>
> Link: https://lore.kernel.org/r/20210623093634.27879-2-jack@xxxxxxx
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
>
> block/bfq-iosched.c | 41 +++++++++++++----------------------------
> 1 file changed, 13 insertions(+), 28 deletions(-)
>
> Holger

Wonderful!

So if you drop that, all works well? I'll go drop that from the queues
now.

thanks,

greg k-h