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@jlekstrand.net Cc: Jon Bloomfield jon.bloomfield@intel.com Cc: Daniel Vetter daniel.vetter@intel.com Cc: Matthew Auld matthew.auld@intel.com Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com
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