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  1. 19 11月, 2019 2 次提交
    • C
      drm/i915/gem: Protect the obj->vma.list during iteration · 53019779
      由 Chris Wilson 提交于 
      Take the obj->vma.lock to prevent modifications to the list as we
iterate, to avoid the dreaded NULL pointer.

<1>[  347.820823] BUG: kernel NULL pointer dereference, address: 0000000000000150
<1>[  347.820856] #PF: supervisor read access in kernel mode
<1>[  347.820874] #PF: error_code(0x0000) - not-present page
<6>[  347.820892] PGD 0 P4D 0
<4>[  347.820908] Oops: 0000 [#1] PREEMPT SMP NOPTI
<4>[  347.820926] CPU: 3 PID: 1303 Comm: gem_persistent_ Tainted: G     U            5.4.0-rc7-CI-CI_DRM_7352+ #1
<4>[  347.820956] Hardware name:  /NUC6CAYB, BIOS AYAPLCEL.86A.0049.2018.0508.1356 05/08/2018
<4>[  347.821132] RIP: 0010:i915_gem_object_flush_write_domain+0xd9/0x1d0 [i915]
<4>[  347.821157] Code: 0f 84 e9 00 00 00 48 8b 80 e0 fd ff ff f6 c4 40 75 11 e9 ed 00 00 00 48 8b 80 e0 fd ff ff f6 c4 40 74 26 48 8b 83 b0 00 00 00 <48> 8b b8 50 01 00 00 e8 fb 20 fb ff 48 8b 83 30 03 00 00 49 39 c4
<4>[  347.821210] RSP: 0018:ffffc90000a1f8f8 EFLAGS: 00010202
<4>[  347.821229] RAX: 0000000000000000 RBX: ffffc900008479a0 RCX: 0000000000000018
<4>[  347.821252] RDX: 0000000000000000 RSI: 000000000000000d RDI: ffff888275a090b0
<4>[  347.821274] RBP: ffff8882673c8040 R08: ffff88825991b8d0 R09: 0000000000000000
<4>[  347.821297] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8882673c8280
<4>[  347.821319] R13: ffff8882673c8368 R14: 0000000000000000 R15: ffff888266a54000
<4>[  347.821343] FS:  00007f75865f4240(0000) GS:ffff888277b80000(0000) knlGS:0000000000000000
<4>[  347.821368] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[  347.821389] CR2: 0000000000000150 CR3: 000000025aee0000 CR4: 00000000003406e0
<4>[  347.821411] Call Trace:
<4>[  347.821555]  i915_gem_object_prepare_read+0xea/0x2a0 [i915]
<4>[  347.821706]  intel_engine_cmd_parser+0x5ce/0xe90 [i915]
<4>[  347.821834]  ? __i915_sw_fence_complete+0x1a0/0x250 [i915]
<4>[  347.821990]  i915_gem_do_execbuffer+0xb4c/0x2550 [i915]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191119100929.2628356-8-chris@chris-wilson.co.uk
      53019779
    • C
      drm/i915/gem: Merge GGTT vma flush into a single loop · 62d1c851
      由 Chris Wilson 提交于 
      We only need the one loop to find the dirty vma flush them and their
chipset.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191119100929.2628356-6-chris@chris-wilson.co.uk
      62d1c851
  3. 07 11月, 2019 1 次提交
    • D
      drm/i915: Switch obj->mm.lock lockdep annotations on its head · f86dbacb
      由 Daniel Vetter 提交于 
      The trouble with having a plain nesting flag for locks which do not
naturally nest (unlike block devices and their partitions, which is
the original motivation for nesting levels) is that lockdep will
never spot a true deadlock if you screw up.

This patch is an attempt at trying better, by highlighting a bit more
of the actual nature of the nesting that's going on. Essentially we
have two kinds of objects:

- objects without pages allocated, which cannot be on any lru and are
  hence inaccessible to the shrinker.

- objects which have pages allocated, which are on an lru, and which
  the shrinker can decide to throw out.

For the former type of object, memory allocations while holding
obj->mm.lock are permissible. For the latter they are not. And
get/put_pages transitions between the two types of objects.

This is still not entirely fool-proof since the rules might change.
But as long as we run such a code ever at runtime lockdep should be
able to observe the inconsistency and complain (like with any other
lockdep class that we've split up in multiple classes). But there are
a few clear benefits:

- We can drop the nesting flag parameter from
  __i915_gem_object_put_pages, because that function by definition is
  never going allocate memory, and calling it on an object which
  doesn't have its pages allocated would be a bug.

- We strictly catch more bugs, since there's not only one place in the
  entire tree which is annotated with the special class. All the
  other places that had explicit lockdep nesting annotations we're now
  going to leave up to lockdep again.

- Specifically this catches stuff like calling get_pages from
  put_pages (which isn't really a good idea, if we can call get_pages
  so could the shrinker). I've seen patches do exactly that.

Of course I fully expect CI will show me for the fool I am with this
one here :-)

v2: There can only be one (lockdep only has a cache for the first
subclass, not for deeper ones, and we don't want to make these locks
even slower). Still separate enums for better documentation.

Real fix: don't forget about phys objs and pin_map(), and fix the
shrinker to have the right annotations ... silly me.

v3: Forgot usertptr too ...

v4: Improve comment for pages_pin_count, drop the IMPORTANT comment
and instead prime lockdep (Chris).

v5: Appease checkpatch, no double empty lines (Chris)

v6: More rebasing over selftest changes. Also somehow I forgot to
push this patch :-/

Also format comments consistently while at it.

v7: Fix typo in commit message (Joonas)

Also drop the priming, with the lmem merge we now have allocations
while holding the lmem lock, which wreaks the generic priming I've
done in earlier patches. Should probably be resurrected when lmem is
fixed. See

commit 232a6eba
Author: Matthew Auld <matthew.auld@intel.com>
Date:   Tue Oct 8 17:01:14 2019 +0100

    drm/i915: introduce intel_memory_region

I'm keeping the priming patch locally so it wont get lost.

Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: "Tang, CQ" <cq.tang@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v5)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v6)
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191105090148.30269-1-daniel.vetter@ffwll.ch
[mlankhorst: Fix commit typos pointed out by Michael Ruhl]
      f86dbacb
  5. 22 10月, 2019 1 次提交
  7. 04 10月, 2019 1 次提交
    • C
      drm/i915: Pull i915_vma_pin under the vm->mutex · 2850748e
      由 Chris Wilson 提交于 
      Replace the struct_mutex requirement for pinning the i915_vma with the
local vm->mutex instead. Note that the vm->mutex is tainted by the
shrinker (we require unbinding from inside fs-reclaim) and so we cannot
allocate while holding that mutex. Instead we have to preallocate
workers to do allocate and apply the PTE updates after we have we
reserved their slot in the drm_mm (using fences to order the PTE writes
with the GPU work and with later unbind).

In adding the asynchronous vma binding, one subtle requirement is to
avoid coupling the binding fence into the backing object->resv. That is
the asynchronous binding only applies to the vma timeline itself and not
to the pages as that is a more global timeline (the binding of one vma
does not need to be ordered with another vma, nor does the implicit GEM
fencing depend on a vma, only on writes to the backing store). Keeping
the vma binding distinct from the backing store timelines is verified by
a number of async gem_exec_fence and gem_exec_schedule tests. The way we
do this is quite simple, we keep the fence for the vma binding separate
and only wait on it as required, and never add it to the obj->resv
itself.

Another consequence in reducing the locking around the vma is the
destruction of the vma is no longer globally serialised by struct_mutex.
A natural solution would be to add a kref to i915_vma, but that requires
decoupling the reference cycles, possibly by introducing a new
i915_mm_pages object that is own by both obj->mm and vma->pages.
However, we have not taken that route due to the overshadowing lmem/ttm
discussions, and instead play a series of complicated games with
trylocks to (hopefully) ensure that only one destruction path is called!

v2: Add some commentary, and some helpers to reduce patch churn.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-4-chris@chris-wilson.co.uk
      2850748e
  9. 11 9月, 2019 1 次提交
  11. 16 8月, 2019 1 次提交
  13. 07 8月, 2019 1 次提交
  15. 04 8月, 2019 1 次提交
  17. 03 8月, 2019 2 次提交
  19. 04 7月, 2019 1 次提交
  21. 03 7月, 2019 1 次提交
  23. 22 6月, 2019 1 次提交
    • C
      drm/i915: Throw away the active object retirement complexity · a93615f9
      由 Chris Wilson 提交于 
      Remove the accumulated optimisations that we have for i915_vma_retire
and reduce it to the bare essential of tracking the active object
reference. This allows us to only use atomic operations, and so will be
able to avoid the struct_mutex requirement.

The principal loss here is the shrinker MRU bumping, so now if we have
to shrink, we will do so in much more random order and more likely to
try and shrink recently used objects. That is a nuisance, but shrinking
active objects is a second step we try to avoid and will always be a
system-wide performance issue.

The other loss is here is in the automatic pruning of the
reservation_object when idling. This is not as large an issue as upon
reservation_object introduction as now adding new fences into the object
replaces already signaled fences, keeping the array compact. But we do
lose the auto-expiration of stale fences and unused arrays. That may be
a noticeable problem for which we need to re-implement autopruning.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190621183801.23252-3-chris@chris-wilson.co.uk
      a93615f9
  25. 21 6月, 2019 1 次提交
  27. 19 6月, 2019 1 次提交
  29. 18 6月, 2019 1 次提交
  31. 17 6月, 2019 1 次提交
  33. 14 6月, 2019 1 次提交
  35. 12 6月, 2019 1 次提交
  37. 11 6月, 2019 1 次提交
  39. 06 6月, 2019 1 次提交
  41. 01 6月, 2019 2 次提交
    • C
      drm/i915: Report all objects with allocated pages to the shrinker · d82b4b26
      由 Chris Wilson 提交于 
      Currently, we try to report to the shrinker the precise number of
objects (pages) that are available to be reaped at this moment. This
requires searching all objects with allocated pages to see if they
fulfill the search criteria, and this count is performed quite
frequently. (The shrinker tries to free ~128 pages on each invocation,
before which we count all the objects; counting takes longer than
unbinding the objects!) If we take the pragmatic view that with
sufficient desire, all objects are eventually reapable (they become
inactive, or no longer used as framebuffer etc), we can simply return
the count of pinned pages maintained during get_pages/put_pages rather
than walk the lists every time.

The downside is that we may (slightly) over-report the number of
objects/pages we could shrink and so penalize ourselves by shrinking
more than required. This is mitigated by keeping the order in which we
shrink objects such that we avoid penalizing active and frequently used
objects, and if memory is so tight that we need to free them we would
need to anyway.

v2: Only expose shrinkable objects to the shrinker; a small reduction in
not considering stolen and foreign objects.
v3: Restore the tracking from a "backup" copy from before the gem/ split
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: NMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190530203500.26272-2-chris@chris-wilson.co.uk
      d82b4b26
    • C
      drm/i915: Track the purgeable objects on a separate eviction list · 3b4fa964
      由 Chris Wilson 提交于 
      Currently the purgeable objects, I915_MADV_DONTNEED, are mixed in the
normal bound/unbound lists. Every shrinker pass starts with an attempt
to purge from this set of unneeded objects, which entails us doing a
walk over both lists looking for any candidates. If there are none, and
since we are shrinking we can reasonably assume that the lists are
full!, this becomes a very slow futile walk.

If we separate out the purgeable objects into own list, this search then
becomes its own phase that is preferentially handled during shrinking.
Instead the cost becomes that we then need to filter the purgeable list
if we want to distinguish between bound and unbound objects.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Reviewed-by: NMatthew Auld <matthew.william.auld@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190530203500.26272-1-chris@chris-wilson.co.uk
      3b4fa964
  43. 31 5月, 2019 1 次提交
  45. 28 5月, 2019 6 次提交
  47. 06 3月, 2019 1 次提交
  49. 28 2月, 2019 1 次提交
  51. 15 8月, 2017 1 次提交
  53. 03 5月, 2017 1 次提交
    • C
      drm/i915: Squash repeated awaits on the same fence · 47979480
      由 Chris Wilson 提交于 
      Track the latest fence waited upon on each context, and only add a new
asynchronous wait if the new fence is more recent than the recorded
fence for that context. This requires us to filter out unordered
timelines, which are noted by DMA_FENCE_NO_CONTEXT. However, in the
absence of a universal identifier, we have to use our own
i915->mm.unordered_timeline token.

v2: Throw around the debug crutches
v3: Inline the likely case of the pre-allocation cache being full.
v4: Drop the pre-allocation support, we can lose the most recent fence
in case of allocation failure -- it just means we may emit more awaits
than strictly necessary but will not break.
v5: Trim allocation size for leaf nodes, they only need an array of u32
not pointers.
v6: Create mock_timeline to tidy selftest writing
v7: s/intel_timeline_sync_get/intel_timeline_sync_is_later/ (Tvrtko)
v8: Prune the stale sync points when we idle.
v9: Include a small benchmark in the kselftests
v10: Separate the idr implementation into its own compartment. (Tvrkto)
v11: Refactor igt_sync kselftests to avoid deep nesting (Tvrkto)
v12: __sync_leaf_idx() to assert that p->height is 0 when checking leaves
v13: kselftests to investigate struct i915_syncmap itself (Tvrtko)
v14: Foray into ascii art graphs
v15: Take into account that the random lookup/insert does 2 prng calls,
not 1, when benchmarking, and use for_each_set_bit() (Tvrtko)
v16: Improved ascii art
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170503093924.5320-4-chris@chris-wilson.co.uk
      47979480
  55. 12 4月, 2017 1 次提交
  57. 14 2月, 2017 1 次提交
  59. 29 10月, 2016 1 次提交
  61. 15 8月, 2016 1 次提交
  63. 03 8月, 2016 1 次提交