> From: Jens Axboe [mailto:axboe@xxxxxxxxx] > Sent: Wednesday, February 8, 2017 00:09 > To: Dexuan Cui <decui@xxxxxxxxxxxxx>; Bart Van Assche > <Bart.VanAssche@xxxxxxxxxxx>; hare@xxxxxxxx; hare@xxxxxxx > Cc: hch@xxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-block@xxxxxxxxxxxxxxx; > jth@xxxxxxxxxx > Subject: Re: [PATCH] genhd: Do not hold event lock when scheduling workqueue > elements > > On 02/06/2017 11:29 PM, Dexuan Cui wrote: > >> From: linux-block-owner@xxxxxxxxxxxxxxx [mailto:linux-block- > >> owner@xxxxxxxxxxxxxxx] On Behalf Of Dexuan Cui > >> with the linux-next kernel. > >> > >> I can boot the guest with linux-next's next-20170130 without any issue, > >> but since next-20170131 I haven't succeeded in booting the guest. > >> > >> With next-20170203 (mentioned in my mail last Friday), I got the same > >> calltrace as Hannes. > >> > >> With today's linux-next (next-20170206), actually the calltrace changed to > >> the below. > >> [ 122.023036] ? remove_wait_queue+0x70/0x70 > >> [ 122.051383] async_synchronize_full+0x17/0x20 > >> [ 122.076925] do_init_module+0xc1/0x1f9 > >> [ 122.097530] load_module+0x24bc/0x2980 > > > > I don't know why it hangs here, but this is the same calltrace in my > > last-Friday mail, which contains 2 calltraces. It looks the other calltrace has > > been resolved by some changes between next-20170203 and today. > > > > Here the kernel is trying to load the Hyper-V storage driver (hv_storvsc), and > > the driver's __init and .probe have finished successfully and then the kernel > > hangs here. > > > > I believe something is broken recently, because I don't have any issue before > > Jan 31. > > Can you try and bisect it? > > Jens Axboe I bisected it on the branch for-4.11/next of the linux-block repo and the log shows the first bad commit is [e9c787e6] scsi: allocate scsi_cmnd structures as part of struct request # git bisect log git bisect start # bad: [80c6b15732f0d8830032149cbcbc8d67e074b5e8] blk-mq-sched: (un)register elevator when (un)registering queue git bisect bad 80c6b15732f0d8830032149cbcbc8d67e074b5e8 # good: [309bd96af9e26da3038661bf5cdad780eef49dd9] md: cleanup bio op / flags handling in raid1_write_request git bisect good 309bd96af9e26da3038661bf5cdad780eef49dd9 # bad: [27410a8927fb89bd150de08d749a8ed7f67b7739] nbd: remove REQ_TYPE_DRV_PRIV leftovers git bisect bad 27410a8927fb89bd150de08d749a8ed7f67b7739 # bad: [e9c787e65c0c36529745be47d490d998b4b6e589] scsi: allocate scsi_cmnd structures as part of struct request git bisect bad e9c787e65c0c36529745be47d490d998b4b6e589 # good: [3278255741326b6d66d8ca7d1cb2c57633ee43d9] scsi_dh_rdac: switch to scsi_execute_req_flags() git bisect good 3278255741326b6d66d8ca7d1cb2c57633ee43d9 # good: [0fbc3e0ff623f1012e7c2af96e781eeb26bcc0d7] scsi: remove gfp_flags member in scsi_host_cmd_pool git bisect good 0fbc3e0ff623f1012e7c2af96e781eeb26bcc0d7 # good: [eeff68c5618c8d0920b14533c70b2df007bd94b4] scsi: remove scsi_cmd_dma_pool git bisect good eeff68c5618c8d0920b14533c70b2df007bd94b4 # good: [d48777a633d6fa7ccde0f0e6509f0c01fbfc5299] scsi: remove __scsi_alloc_queue git bisect good d48777a633d6fa7ccde0f0e6509f0c01fbfc5299 # first bad commit: [e9c787e65c0c36529745be47d490d998b4b6e589] scsi: allocate scsi_cmnd structures as part of struct request Thanks, -- Dexuan
