diff options
author | Chris Wilson <chris@chris-wilson.co.uk> | 2019-10-04 14:40:00 +0100 |
---|---|---|
committer | Chris Wilson <chris@chris-wilson.co.uk> | 2019-10-04 15:39:12 +0100 |
commit | b1e3177bd1d8f41e2a9cc847e56a96cdc0eefe62 (patch) | |
tree | 9af22565533f12868a015e18e51406d54773e08a /drivers/gpu/drm/i915/gt/selftest_context.c | |
parent | 274cbf20fd108fa26d0497282b102e00371210fd (diff) |
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/gt/selftest_context.c')
-rw-r--r-- | drivers/gpu/drm/i915/gt/selftest_context.c | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/drivers/gpu/drm/i915/gt/selftest_context.c b/drivers/gpu/drm/i915/gt/selftest_context.c index 4ce1e25433d2..e6bcbe7ab5e1 100644 --- a/drivers/gpu/drm/i915/gt/selftest_context.c +++ b/drivers/gpu/drm/i915/gt/selftest_context.c @@ -47,24 +47,20 @@ static int context_sync(struct intel_context *ce) mutex_lock(&tl->mutex); do { - struct i915_request *rq; + struct dma_fence *fence; long timeout; - rcu_read_lock(); - rq = rcu_dereference(tl->last_request.request); - if (rq) - rq = i915_request_get_rcu(rq); - rcu_read_unlock(); - if (!rq) + fence = i915_active_fence_get(&tl->last_request); + if (!fence) break; - timeout = i915_request_wait(rq, 0, HZ / 10); + timeout = dma_fence_wait_timeout(fence, false, HZ / 10); if (timeout < 0) err = timeout; else - i915_request_retire_upto(rq); + i915_request_retire_upto(to_request(fence)); - i915_request_put(rq); + dma_fence_put(fence); } while (!err); mutex_unlock(&tl->mutex); |