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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-02-11 17:48:31 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2020-02-12 00:58:39 +0300 |
| commit | 42fb60de3129ef998bb18266ee06530669021e55 (patch) | |
| tree | 97df241bc3c870323e38572ac2e507d41230cd3e /drivers/gpu/drm/i915/i915_sw_fence.c | |
| parent | 0b02f97f40d8e33306f4d724e90b1aff97c3bd46 (diff) | |
| download | linux-42fb60de3129ef998bb18266ee06530669021e55.tar.xz | |
drm/i915/gem: Don't leak non-persistent requests on changing engines
If we have a set of active engines marked as being non-persistent, we
lose track of those if the user replaces those engines with
I915_CONTEXT_PARAM_ENGINES. As part of our uABI contract is that
non-persistent requests are terminated if they are no longer being
tracked by the user's context (in order to prevent a lost request
causing an untracked and so unstoppable GPU hang), we need to apply the
same context cancellation upon changing engines.
v2: Track stale engines[] so we only reap at context closure.
v3: Tvrtko spotted races with closing contexts and set-engines, so add a
veneer of kill-everything paranoia to clean up after losing a race.
Fixes: a0e047156cde ("drm/i915/gem: Make context persistence optional")
Testcase: igt/gem_ctx_peristence/replace
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/20200211144831.1011498-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/i915_sw_fence.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_sw_fence.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c index 51ba97daf2a0..a3d38e089b6e 100644 --- a/drivers/gpu/drm/i915/i915_sw_fence.c +++ b/drivers/gpu/drm/i915/i915_sw_fence.c @@ -211,10 +211,21 @@ void i915_sw_fence_complete(struct i915_sw_fence *fence) __i915_sw_fence_complete(fence, NULL); } -void i915_sw_fence_await(struct i915_sw_fence *fence) +bool i915_sw_fence_await(struct i915_sw_fence *fence) { - debug_fence_assert(fence); - WARN_ON(atomic_inc_return(&fence->pending) <= 1); + int pending; + + /* + * It is only safe to add a new await to the fence while it has + * not yet been signaled (i.e. there are still existing signalers). + */ + pending = atomic_read(&fence->pending); + do { + if (pending < 1) + return false; + } while (!atomic_try_cmpxchg(&fence->pending, &pending, pending + 1)); + + return true; } void __i915_sw_fence_init(struct i915_sw_fence *fence, |