| Message ID | 20250210124203.124191-2-adrian.larumbe@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] drm/panthor: Replace sleep locks with spinlocks in fdinfo path | expand |
On Mon, 10 Feb 2025 12:42:00 +0000 Adrián Larumbe <adrian.larumbe@collabora.com> wrote: > A previous commit dealt with a similar situation, whereby upon enabling > some mutex debug features, a warning about sleep muteces being used in a ^ mutexes > /proc file read atomic context was being triggered. > > Because in this case replacing the heap mutex with a spinlock isn't > feasible, the fdinfo handler no longer traverses the list of heaps for > every single VM associated with an open DRM file. Instad, when a new heap > chunk is allocated, its size is accumulated into a VM-wide tally, which > also makes the atomic context code path somewhat faster. > > Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com> > Fixes: 3e2c8c718567 ("drm/panthor: Expose size of driver internal BO's over fdinfo") > --- > drivers/gpu/drm/panthor/panthor_heap.c | 38 ++++++++------------------ > drivers/gpu/drm/panthor/panthor_heap.h | 2 -- > drivers/gpu/drm/panthor/panthor_mmu.c | 18 +++++++----- > drivers/gpu/drm/panthor/panthor_mmu.h | 1 + > 4 files changed, 23 insertions(+), 36 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_heap.c b/drivers/gpu/drm/panthor/panthor_heap.c > index db0285ce5812..686f209f5b09 100644 > --- a/drivers/gpu/drm/panthor/panthor_heap.c > +++ b/drivers/gpu/drm/panthor/panthor_heap.c > @@ -127,6 +127,8 @@ static void panthor_free_heap_chunk(struct panthor_vm *vm, > heap->chunk_count--; > mutex_unlock(&heap->lock); > > + panthor_vm_heaps_accumulate(vm, -heap->chunk_size); > + > panthor_kernel_bo_destroy(chunk->bo); > kfree(chunk); > } > @@ -180,6 +182,8 @@ static int panthor_alloc_heap_chunk(struct panthor_device *ptdev, > heap->chunk_count++; > mutex_unlock(&heap->lock); > > + panthor_vm_heaps_accumulate(vm, heap->chunk_size); > + > return 0; > > err_destroy_bo: > @@ -389,6 +393,7 @@ int panthor_heap_return_chunk(struct panthor_heap_pool *pool, > removed = chunk; > list_del(&chunk->node); > heap->chunk_count--; > + panthor_vm_heaps_accumulate(chunk->bo->vm, -heap->chunk_size); > break; > } > } > @@ -560,6 +565,8 @@ panthor_heap_pool_create(struct panthor_device *ptdev, struct panthor_vm *vm) > if (ret) > goto err_destroy_pool; > > + panthor_vm_heaps_accumulate(vm, pool->gpu_contexts->obj->size); > + > return pool; > > err_destroy_pool: > @@ -594,8 +601,11 @@ void panthor_heap_pool_destroy(struct panthor_heap_pool *pool) > xa_for_each(&pool->xa, i, heap) > drm_WARN_ON(&pool->ptdev->base, panthor_heap_destroy_locked(pool, i)); > > - if (!IS_ERR_OR_NULL(pool->gpu_contexts)) > + if (!IS_ERR_OR_NULL(pool->gpu_contexts)) { > + panthor_vm_heaps_accumulate(pool->gpu_contexts->vm, > + -pool->gpu_contexts->obj->size); > panthor_kernel_bo_destroy(pool->gpu_contexts); > + } > > /* Reflects the fact the pool has been destroyed. */ > pool->vm = NULL; > @@ -603,29 +613,3 @@ void panthor_heap_pool_destroy(struct panthor_heap_pool *pool) > > panthor_heap_pool_put(pool); > } > - > -/** > - * panthor_heap_pool_size() - Calculate size of all chunks across all heaps in a pool > - * @pool: Pool whose total chunk size to calculate. > - * > - * This function adds the size of all heap chunks across all heaps in the > - * argument pool. It also adds the size of the gpu contexts kernel bo. > - * It is meant to be used by fdinfo for displaying the size of internal > - * driver BO's that aren't exposed to userspace through a GEM handle. > - * > - */ > -size_t panthor_heap_pool_size(struct panthor_heap_pool *pool) > -{ > - struct panthor_heap *heap; > - unsigned long i; > - size_t size = 0; > - > - down_read(&pool->lock); > - xa_for_each(&pool->xa, i, heap) > - size += heap->chunk_size * heap->chunk_count; > - up_read(&pool->lock); > - > - size += pool->gpu_contexts->obj->size; > - > - return size; > -} > diff --git a/drivers/gpu/drm/panthor/panthor_heap.h b/drivers/gpu/drm/panthor/panthor_heap.h > index e3358d4e8edb..25a5f2bba445 100644 > --- a/drivers/gpu/drm/panthor/panthor_heap.h > +++ b/drivers/gpu/drm/panthor/panthor_heap.h > @@ -27,8 +27,6 @@ struct panthor_heap_pool * > panthor_heap_pool_get(struct panthor_heap_pool *pool); > void panthor_heap_pool_put(struct panthor_heap_pool *pool); > > -size_t panthor_heap_pool_size(struct panthor_heap_pool *pool); > - > int panthor_heap_grow(struct panthor_heap_pool *pool, > u64 heap_gpu_va, > u32 renderpasses_in_flight, > diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c > index 0a4e352b5505..aaad1a560805 100644 > --- a/drivers/gpu/drm/panthor/panthor_mmu.c > +++ b/drivers/gpu/drm/panthor/panthor_mmu.c > @@ -345,6 +345,10 @@ struct panthor_vm { > > /** @heaps.lock: Lock used to protect access to @pool. */ > struct mutex lock; > + > + /** @heaps.size: Size of all chunks across all heaps in the pool. */ > + ssize_t size; Let's put that into an fdinfo struct. > + Drop the extra blank-line. > } heaps; > > /** @node: Used to insert the VM in the panthor_mmu::vm::list. */ > @@ -1539,6 +1543,7 @@ static void panthor_vm_destroy(struct panthor_vm *vm) > mutex_lock(&vm->heaps.lock); > panthor_heap_pool_destroy(vm->heaps.pool); > vm->heaps.pool = NULL; > + vm->heaps.size = 0; > mutex_unlock(&vm->heaps.lock); > > drm_WARN_ON(&vm->ptdev->base, > @@ -1963,13 +1968,7 @@ void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats > > xa_lock(&pfile->vms->xa); > xa_for_each(&pfile->vms->xa, i, vm) { > - size_t size = 0; > - > - mutex_lock(&vm->heaps.lock); > - if (vm->heaps.pool) > - size = panthor_heap_pool_size(vm->heaps.pool); > - mutex_unlock(&vm->heaps.lock); > - > + size_t size = vm->heaps.size; > stats->resident += size; > if (vm->as.id >= 0) > stats->active += size; > @@ -1977,6 +1976,11 @@ void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats > xa_unlock(&pfile->vms->xa); > } > > +void panthor_vm_heaps_accumulate(struct panthor_vm *vm, ssize_t acc) > +{ Either there's some lock protecting this operation and we want a lockdep_assert_held(), or we need to make it an atomic operation (and make the size an atomic_t) to avoid races. > + vm->heaps.size += acc; > +} > + > static u64 mair_to_memattr(u64 mair, bool coherent) > { > u64 memattr = 0; > diff --git a/drivers/gpu/drm/panthor/panthor_mmu.h b/drivers/gpu/drm/panthor/panthor_mmu.h > index fc274637114e..b6686896f8ef 100644 > --- a/drivers/gpu/drm/panthor/panthor_mmu.h > +++ b/drivers/gpu/drm/panthor/panthor_mmu.h > @@ -39,6 +39,7 @@ struct panthor_heap_pool * > panthor_vm_get_heap_pool(struct panthor_vm *vm, bool create); > > void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats *stats); > +void panthor_vm_heaps_accumulate(struct panthor_vm *vm, ssize_t acc); > > struct panthor_vm *panthor_vm_get(struct panthor_vm *vm); > void panthor_vm_put(struct panthor_vm *vm);
On Mon, Feb 10, 2025 at 02:18:07PM +0100, Boris Brezillon wrote: > On Mon, 10 Feb 2025 12:42:00 +0000 > Adrián Larumbe <adrian.larumbe@collabora.com> wrote: > > > A previous commit dealt with a similar situation, whereby upon enabling > > some mutex debug features, a warning about sleep muteces being used in a > > ^ mutexes > > > /proc file read atomic context was being triggered. > > > > Because in this case replacing the heap mutex with a spinlock isn't > > feasible, the fdinfo handler no longer traverses the list of heaps for > > every single VM associated with an open DRM file. Instad, when a new heap > > chunk is allocated, its size is accumulated into a VM-wide tally, which > > also makes the atomic context code path somewhat faster. > > > > Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com> > > Fixes: 3e2c8c718567 ("drm/panthor: Expose size of driver internal BO's over fdinfo") > > --- > > drivers/gpu/drm/panthor/panthor_heap.c | 38 ++++++++------------------ > > drivers/gpu/drm/panthor/panthor_heap.h | 2 -- > > drivers/gpu/drm/panthor/panthor_mmu.c | 18 +++++++----- > > drivers/gpu/drm/panthor/panthor_mmu.h | 1 + > > 4 files changed, 23 insertions(+), 36 deletions(-) > > > > diff --git a/drivers/gpu/drm/panthor/panthor_heap.c b/drivers/gpu/drm/panthor/panthor_heap.c > > index db0285ce5812..686f209f5b09 100644 > > --- a/drivers/gpu/drm/panthor/panthor_heap.c > > +++ b/drivers/gpu/drm/panthor/panthor_heap.c > > @@ -127,6 +127,8 @@ static void panthor_free_heap_chunk(struct panthor_vm *vm, > > heap->chunk_count--; > > mutex_unlock(&heap->lock); > > > > + panthor_vm_heaps_accumulate(vm, -heap->chunk_size); > > + > > panthor_kernel_bo_destroy(chunk->bo); > > kfree(chunk); > > } > > @@ -180,6 +182,8 @@ static int panthor_alloc_heap_chunk(struct panthor_device *ptdev, > > heap->chunk_count++; > > mutex_unlock(&heap->lock); > > > > + panthor_vm_heaps_accumulate(vm, heap->chunk_size); > > + > > return 0; > > > > err_destroy_bo: > > @@ -389,6 +393,7 @@ int panthor_heap_return_chunk(struct panthor_heap_pool *pool, > > removed = chunk; > > list_del(&chunk->node); > > heap->chunk_count--; > > + panthor_vm_heaps_accumulate(chunk->bo->vm, -heap->chunk_size); > > break; > > } > > } > > @@ -560,6 +565,8 @@ panthor_heap_pool_create(struct panthor_device *ptdev, struct panthor_vm *vm) > > if (ret) > > goto err_destroy_pool; > > > > + panthor_vm_heaps_accumulate(vm, pool->gpu_contexts->obj->size); > > + > > return pool; > > > > err_destroy_pool: > > @@ -594,8 +601,11 @@ void panthor_heap_pool_destroy(struct panthor_heap_pool *pool) > > xa_for_each(&pool->xa, i, heap) > > drm_WARN_ON(&pool->ptdev->base, panthor_heap_destroy_locked(pool, i)); > > > > - if (!IS_ERR_OR_NULL(pool->gpu_contexts)) > > + if (!IS_ERR_OR_NULL(pool->gpu_contexts)) { > > + panthor_vm_heaps_accumulate(pool->gpu_contexts->vm, > > + -pool->gpu_contexts->obj->size); > > panthor_kernel_bo_destroy(pool->gpu_contexts); > > + } > > > > /* Reflects the fact the pool has been destroyed. */ > > pool->vm = NULL; > > @@ -603,29 +613,3 @@ void panthor_heap_pool_destroy(struct panthor_heap_pool *pool) > > > > panthor_heap_pool_put(pool); > > } > > - > > -/** > > - * panthor_heap_pool_size() - Calculate size of all chunks across all heaps in a pool > > - * @pool: Pool whose total chunk size to calculate. > > - * > > - * This function adds the size of all heap chunks across all heaps in the > > - * argument pool. It also adds the size of the gpu contexts kernel bo. > > - * It is meant to be used by fdinfo for displaying the size of internal > > - * driver BO's that aren't exposed to userspace through a GEM handle. > > - * > > - */ > > -size_t panthor_heap_pool_size(struct panthor_heap_pool *pool) > > -{ > > - struct panthor_heap *heap; > > - unsigned long i; > > - size_t size = 0; > > - > > - down_read(&pool->lock); > > - xa_for_each(&pool->xa, i, heap) > > - size += heap->chunk_size * heap->chunk_count; > > - up_read(&pool->lock); > > - > > - size += pool->gpu_contexts->obj->size; > > - > > - return size; > > -} > > diff --git a/drivers/gpu/drm/panthor/panthor_heap.h b/drivers/gpu/drm/panthor/panthor_heap.h > > index e3358d4e8edb..25a5f2bba445 100644 > > --- a/drivers/gpu/drm/panthor/panthor_heap.h > > +++ b/drivers/gpu/drm/panthor/panthor_heap.h > > @@ -27,8 +27,6 @@ struct panthor_heap_pool * > > panthor_heap_pool_get(struct panthor_heap_pool *pool); > > void panthor_heap_pool_put(struct panthor_heap_pool *pool); > > > > -size_t panthor_heap_pool_size(struct panthor_heap_pool *pool); > > - > > int panthor_heap_grow(struct panthor_heap_pool *pool, > > u64 heap_gpu_va, > > u32 renderpasses_in_flight, > > diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c > > index 0a4e352b5505..aaad1a560805 100644 > > --- a/drivers/gpu/drm/panthor/panthor_mmu.c > > +++ b/drivers/gpu/drm/panthor/panthor_mmu.c > > @@ -345,6 +345,10 @@ struct panthor_vm { > > > > /** @heaps.lock: Lock used to protect access to @pool. */ > > struct mutex lock; > > + > > + /** @heaps.size: Size of all chunks across all heaps in the pool. */ > > + ssize_t size; > > Let's put that into an fdinfo struct. > > > + > > Drop the extra blank-line. > > > } heaps; > > > > /** @node: Used to insert the VM in the panthor_mmu::vm::list. */ > > @@ -1539,6 +1543,7 @@ static void panthor_vm_destroy(struct panthor_vm *vm) > > mutex_lock(&vm->heaps.lock); > > panthor_heap_pool_destroy(vm->heaps.pool); > > vm->heaps.pool = NULL; > > + vm->heaps.size = 0; > > mutex_unlock(&vm->heaps.lock); > > > > drm_WARN_ON(&vm->ptdev->base, > > @@ -1963,13 +1968,7 @@ void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats > > > > xa_lock(&pfile->vms->xa); > > xa_for_each(&pfile->vms->xa, i, vm) { > > - size_t size = 0; > > - > > - mutex_lock(&vm->heaps.lock); > > - if (vm->heaps.pool) > > - size = panthor_heap_pool_size(vm->heaps.pool); > > - mutex_unlock(&vm->heaps.lock); > > - > > + size_t size = vm->heaps.size; > > stats->resident += size; > > if (vm->as.id >= 0) > > stats->active += size; > > @@ -1977,6 +1976,11 @@ void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats > > xa_unlock(&pfile->vms->xa); > > } > > > > +void panthor_vm_heaps_accumulate(struct panthor_vm *vm, ssize_t acc) > > +{ > > Either there's some lock protecting this operation and we want a > lockdep_assert_held(), or we need to make it an atomic operation (and > make the size an atomic_t) to avoid races. If Adrián moves the call site in panthor_{alloc,free}_heap_chunk() before he drops the heap->lock, would that be sufficient? Pool create and destroy are hopefully race-free and panthor_heap_return_chunk() should be also safe. Best regards, Liviu > > > + vm->heaps.size += acc; > > +} > > + > > static u64 mair_to_memattr(u64 mair, bool coherent) > > { > > u64 memattr = 0; > > diff --git a/drivers/gpu/drm/panthor/panthor_mmu.h b/drivers/gpu/drm/panthor/panthor_mmu.h > > index fc274637114e..b6686896f8ef 100644 > > --- a/drivers/gpu/drm/panthor/panthor_mmu.h > > +++ b/drivers/gpu/drm/panthor/panthor_mmu.h > > @@ -39,6 +39,7 @@ struct panthor_heap_pool * > > panthor_vm_get_heap_pool(struct panthor_vm *vm, bool create); > > > > void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats *stats); > > +void panthor_vm_heaps_accumulate(struct panthor_vm *vm, ssize_t acc); > > > > struct panthor_vm *panthor_vm_get(struct panthor_vm *vm); > > void panthor_vm_put(struct panthor_vm *vm); >
On Mon, 10 Feb 2025 13:43:17 +0000 Liviu Dudau <liviu.dudau@arm.com> wrote: > On Mon, Feb 10, 2025 at 02:18:07PM +0100, Boris Brezillon wrote: > > On Mon, 10 Feb 2025 12:42:00 +0000 > > Adrián Larumbe <adrian.larumbe@collabora.com> wrote: > > > > > A previous commit dealt with a similar situation, whereby upon enabling > > > some mutex debug features, a warning about sleep muteces being used in a > > > > ^ mutexes > > > > > /proc file read atomic context was being triggered. > > > > > > Because in this case replacing the heap mutex with a spinlock isn't > > > feasible, the fdinfo handler no longer traverses the list of heaps for > > > every single VM associated with an open DRM file. Instad, when a new heap > > > chunk is allocated, its size is accumulated into a VM-wide tally, which > > > also makes the atomic context code path somewhat faster. > > > > > > Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com> > > > Fixes: 3e2c8c718567 ("drm/panthor: Expose size of driver internal BO's over fdinfo") > > > --- > > > drivers/gpu/drm/panthor/panthor_heap.c | 38 ++++++++------------------ > > > drivers/gpu/drm/panthor/panthor_heap.h | 2 -- > > > drivers/gpu/drm/panthor/panthor_mmu.c | 18 +++++++----- > > > drivers/gpu/drm/panthor/panthor_mmu.h | 1 + > > > 4 files changed, 23 insertions(+), 36 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/panthor/panthor_heap.c b/drivers/gpu/drm/panthor/panthor_heap.c > > > index db0285ce5812..686f209f5b09 100644 > > > --- a/drivers/gpu/drm/panthor/panthor_heap.c > > > +++ b/drivers/gpu/drm/panthor/panthor_heap.c > > > @@ -127,6 +127,8 @@ static void panthor_free_heap_chunk(struct panthor_vm *vm, > > > heap->chunk_count--; > > > mutex_unlock(&heap->lock); > > > > > > + panthor_vm_heaps_accumulate(vm, -heap->chunk_size); > > > + > > > panthor_kernel_bo_destroy(chunk->bo); > > > kfree(chunk); > > > } > > > @@ -180,6 +182,8 @@ static int panthor_alloc_heap_chunk(struct panthor_device *ptdev, > > > heap->chunk_count++; > > > mutex_unlock(&heap->lock); > > > > > > + panthor_vm_heaps_accumulate(vm, heap->chunk_size); > > > + > > > return 0; > > > > > > err_destroy_bo: > > > @@ -389,6 +393,7 @@ int panthor_heap_return_chunk(struct panthor_heap_pool *pool, > > > removed = chunk; > > > list_del(&chunk->node); > > > heap->chunk_count--; > > > + panthor_vm_heaps_accumulate(chunk->bo->vm, -heap->chunk_size); > > > break; > > > } > > > } > > > @@ -560,6 +565,8 @@ panthor_heap_pool_create(struct panthor_device *ptdev, struct panthor_vm *vm) > > > if (ret) > > > goto err_destroy_pool; > > > > > > + panthor_vm_heaps_accumulate(vm, pool->gpu_contexts->obj->size); > > > + > > > return pool; > > > > > > err_destroy_pool: > > > @@ -594,8 +601,11 @@ void panthor_heap_pool_destroy(struct panthor_heap_pool *pool) > > > xa_for_each(&pool->xa, i, heap) > > > drm_WARN_ON(&pool->ptdev->base, panthor_heap_destroy_locked(pool, i)); > > > > > > - if (!IS_ERR_OR_NULL(pool->gpu_contexts)) > > > + if (!IS_ERR_OR_NULL(pool->gpu_contexts)) { > > > + panthor_vm_heaps_accumulate(pool->gpu_contexts->vm, > > > + -pool->gpu_contexts->obj->size); > > > panthor_kernel_bo_destroy(pool->gpu_contexts); > > > + } > > > > > > /* Reflects the fact the pool has been destroyed. */ > > > pool->vm = NULL; > > > @@ -603,29 +613,3 @@ void panthor_heap_pool_destroy(struct panthor_heap_pool *pool) > > > > > > panthor_heap_pool_put(pool); > > > } > > > - > > > -/** > > > - * panthor_heap_pool_size() - Calculate size of all chunks across all heaps in a pool > > > - * @pool: Pool whose total chunk size to calculate. > > > - * > > > - * This function adds the size of all heap chunks across all heaps in the > > > - * argument pool. It also adds the size of the gpu contexts kernel bo. > > > - * It is meant to be used by fdinfo for displaying the size of internal > > > - * driver BO's that aren't exposed to userspace through a GEM handle. > > > - * > > > - */ > > > -size_t panthor_heap_pool_size(struct panthor_heap_pool *pool) > > > -{ > > > - struct panthor_heap *heap; > > > - unsigned long i; > > > - size_t size = 0; > > > - > > > - down_read(&pool->lock); > > > - xa_for_each(&pool->xa, i, heap) > > > - size += heap->chunk_size * heap->chunk_count; > > > - up_read(&pool->lock); > > > - > > > - size += pool->gpu_contexts->obj->size; > > > - > > > - return size; > > > -} > > > diff --git a/drivers/gpu/drm/panthor/panthor_heap.h b/drivers/gpu/drm/panthor/panthor_heap.h > > > index e3358d4e8edb..25a5f2bba445 100644 > > > --- a/drivers/gpu/drm/panthor/panthor_heap.h > > > +++ b/drivers/gpu/drm/panthor/panthor_heap.h > > > @@ -27,8 +27,6 @@ struct panthor_heap_pool * > > > panthor_heap_pool_get(struct panthor_heap_pool *pool); > > > void panthor_heap_pool_put(struct panthor_heap_pool *pool); > > > > > > -size_t panthor_heap_pool_size(struct panthor_heap_pool *pool); > > > - > > > int panthor_heap_grow(struct panthor_heap_pool *pool, > > > u64 heap_gpu_va, > > > u32 renderpasses_in_flight, > > > diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c > > > index 0a4e352b5505..aaad1a560805 100644 > > > --- a/drivers/gpu/drm/panthor/panthor_mmu.c > > > +++ b/drivers/gpu/drm/panthor/panthor_mmu.c > > > @@ -345,6 +345,10 @@ struct panthor_vm { > > > > > > /** @heaps.lock: Lock used to protect access to @pool. */ > > > struct mutex lock; > > > + > > > + /** @heaps.size: Size of all chunks across all heaps in the pool. */ > > > + ssize_t size; > > > > Let's put that into an fdinfo struct. > > > > > + > > > > Drop the extra blank-line. > > > > > } heaps; > > > > > > /** @node: Used to insert the VM in the panthor_mmu::vm::list. */ > > > @@ -1539,6 +1543,7 @@ static void panthor_vm_destroy(struct panthor_vm *vm) > > > mutex_lock(&vm->heaps.lock); > > > panthor_heap_pool_destroy(vm->heaps.pool); > > > vm->heaps.pool = NULL; > > > + vm->heaps.size = 0; > > > mutex_unlock(&vm->heaps.lock); > > > > > > drm_WARN_ON(&vm->ptdev->base, > > > @@ -1963,13 +1968,7 @@ void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats > > > > > > xa_lock(&pfile->vms->xa); > > > xa_for_each(&pfile->vms->xa, i, vm) { > > > - size_t size = 0; > > > - > > > - mutex_lock(&vm->heaps.lock); > > > - if (vm->heaps.pool) > > > - size = panthor_heap_pool_size(vm->heaps.pool); > > > - mutex_unlock(&vm->heaps.lock); > > > - > > > + size_t size = vm->heaps.size; > > > stats->resident += size; > > > if (vm->as.id >= 0) > > > stats->active += size; > > > @@ -1977,6 +1976,11 @@ void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats > > > xa_unlock(&pfile->vms->xa); > > > } > > > > > > +void panthor_vm_heaps_accumulate(struct panthor_vm *vm, ssize_t acc) > > > +{ > > > > Either there's some lock protecting this operation and we want a > > lockdep_assert_held(), or we need to make it an atomic operation (and > > make the size an atomic_t) to avoid races. > > If Adrián moves the call site in panthor_{alloc,free}_heap_chunk() before he drops the heap->lock, > would that be sufficient? Pool create and destroy are hopefully race-free and > panthor_heap_return_chunk() should be also safe. I'm not sure that's enough. The tiler_oom_work is per-group, and you can have multiple groups sharing the same VM. The workqueue we schedule these works on is also not single-threaded, so you can potentially have multiple threads updating the total VM tiler heap size at the same time.
diff --git a/drivers/gpu/drm/panthor/panthor_heap.c b/drivers/gpu/drm/panthor/panthor_heap.c index db0285ce5812..686f209f5b09 100644 --- a/drivers/gpu/drm/panthor/panthor_heap.c +++ b/drivers/gpu/drm/panthor/panthor_heap.c @@ -127,6 +127,8 @@ static void panthor_free_heap_chunk(struct panthor_vm *vm, heap->chunk_count--; mutex_unlock(&heap->lock); + panthor_vm_heaps_accumulate(vm, -heap->chunk_size); + panthor_kernel_bo_destroy(chunk->bo); kfree(chunk); } @@ -180,6 +182,8 @@ static int panthor_alloc_heap_chunk(struct panthor_device *ptdev, heap->chunk_count++; mutex_unlock(&heap->lock); + panthor_vm_heaps_accumulate(vm, heap->chunk_size); + return 0; err_destroy_bo: @@ -389,6 +393,7 @@ int panthor_heap_return_chunk(struct panthor_heap_pool *pool, removed = chunk; list_del(&chunk->node); heap->chunk_count--; + panthor_vm_heaps_accumulate(chunk->bo->vm, -heap->chunk_size); break; } } @@ -560,6 +565,8 @@ panthor_heap_pool_create(struct panthor_device *ptdev, struct panthor_vm *vm) if (ret) goto err_destroy_pool; + panthor_vm_heaps_accumulate(vm, pool->gpu_contexts->obj->size); + return pool; err_destroy_pool: @@ -594,8 +601,11 @@ void panthor_heap_pool_destroy(struct panthor_heap_pool *pool) xa_for_each(&pool->xa, i, heap) drm_WARN_ON(&pool->ptdev->base, panthor_heap_destroy_locked(pool, i)); - if (!IS_ERR_OR_NULL(pool->gpu_contexts)) + if (!IS_ERR_OR_NULL(pool->gpu_contexts)) { + panthor_vm_heaps_accumulate(pool->gpu_contexts->vm, + -pool->gpu_contexts->obj->size); panthor_kernel_bo_destroy(pool->gpu_contexts); + } /* Reflects the fact the pool has been destroyed. */ pool->vm = NULL; @@ -603,29 +613,3 @@ void panthor_heap_pool_destroy(struct panthor_heap_pool *pool) panthor_heap_pool_put(pool); } - -/** - * panthor_heap_pool_size() - Calculate size of all chunks across all heaps in a pool - * @pool: Pool whose total chunk size to calculate. - * - * This function adds the size of all heap chunks across all heaps in the - * argument pool. It also adds the size of the gpu contexts kernel bo. - * It is meant to be used by fdinfo for displaying the size of internal - * driver BO's that aren't exposed to userspace through a GEM handle. - * - */ -size_t panthor_heap_pool_size(struct panthor_heap_pool *pool) -{ - struct panthor_heap *heap; - unsigned long i; - size_t size = 0; - - down_read(&pool->lock); - xa_for_each(&pool->xa, i, heap) - size += heap->chunk_size * heap->chunk_count; - up_read(&pool->lock); - - size += pool->gpu_contexts->obj->size; - - return size; -} diff --git a/drivers/gpu/drm/panthor/panthor_heap.h b/drivers/gpu/drm/panthor/panthor_heap.h index e3358d4e8edb..25a5f2bba445 100644 --- a/drivers/gpu/drm/panthor/panthor_heap.h +++ b/drivers/gpu/drm/panthor/panthor_heap.h @@ -27,8 +27,6 @@ struct panthor_heap_pool * panthor_heap_pool_get(struct panthor_heap_pool *pool); void panthor_heap_pool_put(struct panthor_heap_pool *pool); -size_t panthor_heap_pool_size(struct panthor_heap_pool *pool); - int panthor_heap_grow(struct panthor_heap_pool *pool, u64 heap_gpu_va, u32 renderpasses_in_flight, diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c index 0a4e352b5505..aaad1a560805 100644 --- a/drivers/gpu/drm/panthor/panthor_mmu.c +++ b/drivers/gpu/drm/panthor/panthor_mmu.c @@ -345,6 +345,10 @@ struct panthor_vm { /** @heaps.lock: Lock used to protect access to @pool. */ struct mutex lock; + + /** @heaps.size: Size of all chunks across all heaps in the pool. */ + ssize_t size; + } heaps; /** @node: Used to insert the VM in the panthor_mmu::vm::list. */ @@ -1539,6 +1543,7 @@ static void panthor_vm_destroy(struct panthor_vm *vm) mutex_lock(&vm->heaps.lock); panthor_heap_pool_destroy(vm->heaps.pool); vm->heaps.pool = NULL; + vm->heaps.size = 0; mutex_unlock(&vm->heaps.lock); drm_WARN_ON(&vm->ptdev->base, @@ -1963,13 +1968,7 @@ void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats xa_lock(&pfile->vms->xa); xa_for_each(&pfile->vms->xa, i, vm) { - size_t size = 0; - - mutex_lock(&vm->heaps.lock); - if (vm->heaps.pool) - size = panthor_heap_pool_size(vm->heaps.pool); - mutex_unlock(&vm->heaps.lock); - + size_t size = vm->heaps.size; stats->resident += size; if (vm->as.id >= 0) stats->active += size; @@ -1977,6 +1976,11 @@ void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats xa_unlock(&pfile->vms->xa); } +void panthor_vm_heaps_accumulate(struct panthor_vm *vm, ssize_t acc) +{ + vm->heaps.size += acc; +} + static u64 mair_to_memattr(u64 mair, bool coherent) { u64 memattr = 0; diff --git a/drivers/gpu/drm/panthor/panthor_mmu.h b/drivers/gpu/drm/panthor/panthor_mmu.h index fc274637114e..b6686896f8ef 100644 --- a/drivers/gpu/drm/panthor/panthor_mmu.h +++ b/drivers/gpu/drm/panthor/panthor_mmu.h @@ -39,6 +39,7 @@ struct panthor_heap_pool * panthor_vm_get_heap_pool(struct panthor_vm *vm, bool create); void panthor_vm_heaps_sizes(struct panthor_file *pfile, struct drm_memory_stats *stats); +void panthor_vm_heaps_accumulate(struct panthor_vm *vm, ssize_t acc); struct panthor_vm *panthor_vm_get(struct panthor_vm *vm); void panthor_vm_put(struct panthor_vm *vm);
A previous commit dealt with a similar situation, whereby upon enabling some mutex debug features, a warning about sleep muteces being used in a /proc file read atomic context was being triggered. Because in this case replacing the heap mutex with a spinlock isn't feasible, the fdinfo handler no longer traverses the list of heaps for every single VM associated with an open DRM file. Instad, when a new heap chunk is allocated, its size is accumulated into a VM-wide tally, which also makes the atomic context code path somewhat faster. Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com> Fixes: 3e2c8c718567 ("drm/panthor: Expose size of driver internal BO's over fdinfo") --- drivers/gpu/drm/panthor/panthor_heap.c | 38 ++++++++------------------ drivers/gpu/drm/panthor/panthor_heap.h | 2 -- drivers/gpu/drm/panthor/panthor_mmu.c | 18 +++++++----- drivers/gpu/drm/panthor/panthor_mmu.h | 1 + 4 files changed, 23 insertions(+), 36 deletions(-)