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author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-10-04 14:40:00 +0100 |
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committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-10-04 15:39:12 +0100 |
commit | b1e3177bd1d8f41e2a9cc847e56a96cdc0eefe62 (patch) | |
tree | 9af22565533f12868a015e18e51406d54773e08a /drivers/gpu/drm/i915/display/intel_frontbuffer.c | |
parent | drm/i915: Push the i915_active.retire into a worker (diff) | |
download | linux-dev-b1e3177bd1d8f41e2a9cc847e56a96cdc0eefe62.tar.xz linux-dev-b1e3177bd1d8f41e2a9cc847e56a96cdc0eefe62.zip |
drm/i915: Coordinate i915_active with its own mutex
Forgo the struct_mutex serialisation for i915_active, and interpose its
own mutex handling for active/retire.
This is a multi-layered sleight-of-hand. First, we had to ensure that no
active/retire callbacks accidentally inverted the mutex ordering rules,
nor assumed that they were themselves serialised by struct_mutex. More
challenging though, is the rule over updating elements of the active
rbtree. Instead of the whole i915_active now being serialised by
struct_mutex, allocations/rotations of the tree are serialised by the
i915_active.mutex and individual nodes are serialised by the caller
using the i915_timeline.mutex (we need to use nested spinlocks to
interact with the dma_fence callback lists).
The pain point here is that instead of a single mutex around execbuf, we
now have to take a mutex for active tracker (one for each vma, context,
etc) and a couple of spinlocks for each fence update. The improvement in
fine grained locking allowing for multiple concurrent clients
(eventually!) should be worth it in typical loads.
v2: Add some comments that barely elucidate anything :(
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191004134015.13204-6-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/display/intel_frontbuffer.c')
-rw-r--r-- | drivers/gpu/drm/i915/display/intel_frontbuffer.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c index 6428b8dd70d3..84b164f31895 100644 --- a/drivers/gpu/drm/i915/display/intel_frontbuffer.c +++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c @@ -257,7 +257,7 @@ intel_frontbuffer_get(struct drm_i915_gem_object *obj) front->obj = obj; kref_init(&front->ref); atomic_set(&front->bits, 0); - i915_active_init(i915, &front->write, + i915_active_init(&front->write, frontbuffer_active, i915_active_may_sleep(frontbuffer_retire)); |