delete hang forever
florisch opened this issue · comments
Hi,
I've been using udmabuf for quite some time now with buffers being defined on modprobe and using rmmod to destroy them. Now after updating to latest version, I am trying to use u-dma-buf-mgr to create and delete my buffers on demand. Creation seems to work but delete hang forever.
root@hw1:~# uname -a
Linux hw1 4.4.0-xilinx-00003-g5d53636e #44 SMP PREEMPT Wed Nov 18 09:13:00 CET 2020 armv7l GNU/Linux
root@hw1:~# modprobe udmabuf
root@hw1:~# echo "create udmabuf0 4096" > /dev/u-dma-buf-mgr
u-dma-buf-mgr : create udmabuf0 4096
u-dma-buf udmabuf0: driver version = 3.2.2
u-dma-buf udmabuf0: major number = 247
u-dma-buf udmabuf0: minor number = 0
u-dma-buf udmabuf0: phys address = 0x1f043000
u-dma-buf udmabuf0: buffer size = 4096
u-dma-buf u-dma-buf.0.auto: driver installed.
root@hw1:~# cat /sys/class/u-dma-buf/udmabuf0/phys_addr
0x1f043000
root@hw1:~# cat /sys/class/u-dma-buf/udmabuf0/size
4096
root@hw1:~# echo "delete udmabuf0" > /dev/u-dma-buf-mgr
u-dma-buf-mgr : delete udmabuf0
The echo "delete udmabuf0" > /dev/u-dma-buf-mgr never returns. Then after 120sec, the hang is detected by kernel with the log below.
INFO: task sh:1022 blocked for more than 120 seconds.
Tainted: G O 4.4.0-xilinx-00003-g5d53636e #44
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
sh D 4047e004 0 1022 1021 0x00000001
[<4047e004>] (__schedule) from [<4047e324>] (schedule+0x50/0xc0)
[<4047e324>] (schedule) from [<4047e758>] (schedule_preempt_disabled+0x24/0x40)
[<4047e758>] (schedule_preempt_disabled) from [<4047fc2c>] (__mutex_lock_slowpath+0xc8/0x168)
[<4047fc2c>] (__mutex_lock_slowpath) from [<4047fd14>] (mutex_lock+0x48/0x4c)
[<4047fd14>] (mutex_lock) from [<3f0750f4>] (udmabuf_get_device_name_property+0x1c/0x7c [udmabuf])
[<3f0750f4>] (udmabuf_get_device_name_property [udmabuf]) from [<3f075858>] (udmabuf_manager_file_write+0x364/0x4dc [udmabuf])
[<3f075858>] (udmabuf_manager_file_write [udmabuf]) from [<400d550c>] (__vfs_write+0x20/0xc8)
[<400d550c>] (__vfs_write) from [<400d5d00>] (vfs_write+0x90/0x164)
[<400d5d00>] (vfs_write) from [<400d651c>] (SyS_write+0x44/0x9c)
[<400d651c>] (SyS_write) from [<4000f6c0>] (ret_fast_syscall+0x0/0x3c)
Thank you.
Thank you for the issue.
This has been fixed in u-dma-buf v3.2.3.
Thank you again for everything you’ve done
Thanks you for fixing this issue so quickly.
Work fine now.