Re: [Intel-gfx] [linux-mmotm] i915_gem_userptr_get_pages: possible circular locking dependency detected
On Tue, Mar 14, 2017 at 10:21:09PM +0900, Sergey Senozhatsky wrote:
> Hello,
>
> [ 530.698622] ==
> [ 530.698623] WARNING: possible circular locking dependency detected
> [ 530.698626] 4.11.0-rc2-mm1-dbg-00167-gdb8a9941614c-dirty #222 Not tainted
> [ 530.698627] --
> [ 530.698628] Xorg/343 is trying to acquire lock:
> [ 530.698630] (>mmap_sem){++}, at: []
> i915_gem_userptr_get_pages+0x60/0x29c [i915]
> [ 530.698702]
>but task is already holding lock:
> [ 530.698703] (>mm.lock){+.+.+.}, at: []
> __i915_gem_object_get_pages+0x21/0x62 [i915]
> [ 530.698763]
>which lock already depends on the new lock.
Yup, just seen it myself. This particular cycle is a non-issue, but
there is another possiblity for a mmap_sem recursion in the ggtt fault
handler.
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
Re: [Intel-gfx] [linux-mmotm] i915_gem_userptr_get_pages: possible circular locking dependency detected
On Tue, Mar 14, 2017 at 10:21:09PM +0900, Sergey Senozhatsky wrote:
> Hello,
>
> [ 530.698622] ==
> [ 530.698623] WARNING: possible circular locking dependency detected
> [ 530.698626] 4.11.0-rc2-mm1-dbg-00167-gdb8a9941614c-dirty #222 Not tainted
> [ 530.698627] --
> [ 530.698628] Xorg/343 is trying to acquire lock:
> [ 530.698630] (>mmap_sem){++}, at: []
> i915_gem_userptr_get_pages+0x60/0x29c [i915]
> [ 530.698702]
>but task is already holding lock:
> [ 530.698703] (>mm.lock){+.+.+.}, at: []
> __i915_gem_object_get_pages+0x21/0x62 [i915]
> [ 530.698763]
>which lock already depends on the new lock.
Yup, just seen it myself. This particular cycle is a non-issue, but
there is another possiblity for a mmap_sem recursion in the ggtt fault
handler.
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
