On 09/06/2021 22:29, Jason Ekstrand wrote:
This appears to break encapsulation by moving an intel_engine_cs
function to a i915_request file. However, this function is
intrinsically tied to the lifetime rules and allocation scheme of
i915_request and having it in intel_engine_cs.c leaks details of
i915_request. We have an abstraction leak either way. Since
i915_request's allocation scheme is far more subtle than the simple
pointer that is intel_engine_cs.request_pool, it's probably better to
keep i915_request's details to itself.
Signed-off-by: Jason Ekstrand <jason@xxxxxxxxxxxxxx>
Cc: Jon Bloomfield <jon.bloomfield@xxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_engine_cs.c | 8 --------
drivers/gpu/drm/i915/i915_request.c | 7 +++++--
drivers/gpu/drm/i915/i915_request.h | 2 --
3 files changed, 5 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 9ceddfbb1687d..df6b80ec84199 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -422,14 +422,6 @@ void intel_engines_release(struct intel_gt *gt)
}
}
-void intel_engine_free_request_pool(struct intel_engine_cs *engine)
-{
- if (!engine->request_pool)
- return;
-
- kmem_cache_free(i915_request_slab_cache(), engine->request_pool);
Argument that the slab cache shouldn't be exported from i915_request.c
sounds good to me.
But I think step better than simply reversing the break of encapsulation
(And it's even worse because it leaks much higher level object!) could
be to export a freeing helper from i915_request.c, engine pool would
then use:
void __i915_request_free(...)
{
kmem_cache_free(...);
}
?
Regards,
Tvrtko
-}
-
void intel_engines_free(struct intel_gt *gt)
{
struct intel_engine_cs *engine;
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 1014c71cf7f52..48c5f8527854b 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -106,9 +106,12 @@ static signed long i915_fence_wait(struct dma_fence *fence,
timeout);
}
-struct kmem_cache *i915_request_slab_cache(void)
+void intel_engine_free_request_pool(struct intel_engine_cs *engine)
{
- return global.slab_requests;
+ if (!engine->request_pool)
+ return;
+
+ kmem_cache_free(global.slab_requests, engine->request_pool);
}
static void i915_fence_release(struct dma_fence *fence)
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 270f6cd37650c..f84c38d29f988 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -300,8 +300,6 @@ static inline bool dma_fence_is_i915(const struct dma_fence *fence)
return fence->ops == &i915_fence_ops;
}
-struct kmem_cache *i915_request_slab_cache(void);
-
struct i915_request * __must_check
__i915_request_create(struct intel_context *ce, gfp_t gfp);
struct i915_request * __must_check
