af23facc38
Do an early rejection of a i915_vma_unbind() attempt if the i915_vma is
currently pinned, without waiting to see if the inflight operations may
unpin it. We see this problem with the shrinker trying to unbind the
active vma from inside its bind worker:
<6> [472.618968] Workqueue: events_unbound fence_work [i915]
<4> [472.618970] Call Trace:
<4> [472.618974] ? __schedule+0x2e5/0x810
<4> [472.618978] schedule+0x37/0xe0
<4> [472.618982] schedule_preempt_disabled+0xf/0x20
<4> [472.618984] __mutex_lock+0x281/0x9c0
<4> [472.618987] ? mark_held_locks+0x49/0x70
<4> [472.618989] ? _raw_spin_unlock_irqrestore+0x47/0x60
<4> [472.619038] ? i915_vma_unbind+0xae/0x110 [i915]
<4> [472.619084] ? i915_vma_unbind+0xae/0x110 [i915]
<4> [472.619122] i915_vma_unbind+0xae/0x110 [i915]
<4> [472.619165] i915_gem_object_unbind+0x1dc/0x400 [i915]
<4> [472.619208] i915_gem_shrink+0x328/0x660 [i915]
<4> [472.619250] ? i915_gem_shrink_all+0x38/0x60 [i915]
<4> [472.619282] i915_gem_shrink_all+0x38/0x60 [i915]
<4> [472.619325] vm_alloc_page.constprop.25+0x1aa/0x240 [i915]
<4> [472.619330] ? rcu_read_lock_sched_held+0x4d/0x80
<4> [472.619363] ? __alloc_pd+0xb/0x30 [i915]
<4> [472.619366] ? module_assert_mutex_or_preempt+0xf/0x30
<4> [472.619368] ? __module_address+0x23/0xe0
<4> [472.619371] ? is_module_address+0x26/0x40
<4> [472.619374] ? static_obj+0x34/0x50
<4> [472.619376] ? lockdep_init_map+0x4d/0x1e0
<4> [472.619407] setup_page_dma+0xd/0x90 [i915]
<4> [472.619437] alloc_pd+0x29/0x50 [i915]
<4> [472.619470] __gen8_ppgtt_alloc+0x443/0x6b0 [i915]
<4> [472.619503] gen8_ppgtt_alloc+0xd7/0x300 [i915]
<4> [472.619535] ppgtt_bind_vma+0x2a/0xe0 [i915]
<4> [472.619577] __vma_bind+0x26/0x40 [i915]
<4> [472.619611] fence_work+0x1c/0x90 [i915]
<4> [472.619617] process_one_work+0x26a/0x620
Fixes: 2850748ef876 ("drm/i915: Pull i915_vma_pin under the vm->mutex")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200403120150.17091-1-chris@chris-wilson.co.uk
(cherry picked from commit 614654abe847a42fc75d7eb5096e46f796a438b6)
(cherry picked from commit dd086cf516d9bea3878abb267f62ccc53acd764b)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.