d5a480b44b
After starting VNC server or running CTS test, kernel will hang and can see below call trace: [961816] INFO: task khugepaged:42 blocked for more than 120 seconds. [968581] Tainted: G OE 4.13.0 #1 [973495] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [980962] khugepaged D 0 42 2 0x00000000 [980967] Call Trace: [980977] __schedule+0x28d/0x890 [980982] schedule+0x36/0x80 [980986] rwsem_down_read_failed+0x139/0x1c0 [980991] ? update_curr+0x100/0x1c0 [981004] call_rwsem_down_read_failed+0x18/0x30 [981007] down_read+0x20/0x40 [981012] khugepaged_scan_mm_slot+0x78/0x1ac0 [981018] ? __switch_to+0x23e/0x4a0 [981022] ? finish_task_switch+0x79/0x240 [981026] khugepaged+0x146/0x480 [981031] ? remove_wait_queue+0x60/0x60 [981035] kthread+0x109/0x140 [981037] ? khugepaged_scan_mm_slot+0x1ac0/0x1ac0 [981039] ? kthread_park+0x60/0x60 [981044] ret_from_fork+0x25/0x30 After checking code and found 'commit b72cf4fca2bb7 ("drm/amdgpu: move taking mmap_sem into get_user_pages v2")' forget to drop one case of up_read. Signed-off-by: Xiangliang.Yu <Xiangliang.Yu@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.