[PATCH 3/3] drm/ttm: switch to per device LRU lock
Daniel Vetter
daniel at ffwll.ch
Tue Mar 16 09:35:54 UTC 2021
On Mon, Mar 15, 2021 at 05:04:22PM +0100, Christian König wrote:
> Instead of having a global lock.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
I guess per zone lru lock is a lot more work since then we need to handle
ordering and ABBA deadlocks? s/zone/mem region/ I think is the proper ttm
lingo.
-Daniel
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 8 ++---
> drivers/gpu/drm/qxl/qxl_release.c | 5 +--
> drivers/gpu/drm/ttm/ttm_bo.c | 49 ++++++++++++--------------
> drivers/gpu/drm/ttm/ttm_device.c | 12 +++----
> drivers/gpu/drm/ttm/ttm_execbuf_util.c | 8 ++---
> drivers/gpu/drm/ttm/ttm_resource.c | 9 +++--
> include/drm/ttm/ttm_bo_driver.h | 4 +--
> include/drm/ttm/ttm_device.h | 4 +--
> 8 files changed, 43 insertions(+), 56 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 9d19078246c8..ae18c0e32347 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -638,15 +638,15 @@ void amdgpu_vm_move_to_lru_tail(struct amdgpu_device *adev,
> struct amdgpu_vm_bo_base *bo_base;
>
> if (vm->bulk_moveable) {
> - spin_lock(&ttm_glob.lru_lock);
> + spin_lock(&adev->mman.bdev.lru_lock);
> ttm_bo_bulk_move_lru_tail(&vm->lru_bulk_move);
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&adev->mman.bdev.lru_lock);
> return;
> }
>
> memset(&vm->lru_bulk_move, 0, sizeof(vm->lru_bulk_move));
>
> - spin_lock(&ttm_glob.lru_lock);
> + spin_lock(&adev->mman.bdev.lru_lock);
> list_for_each_entry(bo_base, &vm->idle, vm_status) {
> struct amdgpu_bo *bo = bo_base->bo;
>
> @@ -660,7 +660,7 @@ void amdgpu_vm_move_to_lru_tail(struct amdgpu_device *adev,
> &bo->shadow->tbo.mem,
> &vm->lru_bulk_move);
> }
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&adev->mman.bdev.lru_lock);
>
> vm->bulk_moveable = true;
> }
> diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c
> index f5845c96d414..b19f2f00b215 100644
> --- a/drivers/gpu/drm/qxl/qxl_release.c
> +++ b/drivers/gpu/drm/qxl/qxl_release.c
> @@ -426,16 +426,13 @@ void qxl_release_fence_buffer_objects(struct qxl_release *release)
> release->id | 0xf0000000, release->base.seqno);
> trace_dma_fence_emit(&release->base);
>
> - spin_lock(&ttm_glob.lru_lock);
> -
> list_for_each_entry(entry, &release->bos, head) {
> bo = entry->bo;
>
> dma_resv_add_shared_fence(bo->base.resv, &release->base);
> - ttm_bo_move_to_lru_tail(bo, &bo->mem, NULL);
> + ttm_bo_move_to_lru_tail_unlocked(bo);
> dma_resv_unlock(bo->base.resv);
> }
> - spin_unlock(&ttm_glob.lru_lock);
> ww_acquire_fini(&release->ticket);
> }
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index a1be88be357b..a8103c8718a3 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -242,9 +242,9 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
> * reference it any more. The only tricky case is the trylock on
> * the resv object while holding the lru_lock.
> */
> - spin_lock(&ttm_glob.lru_lock);
> + spin_lock(&bo->bdev->lru_lock);
> bo->base.resv = &bo->base._resv;
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
> }
>
> return r;
> @@ -303,7 +303,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
>
> if (unlock_resv)
> dma_resv_unlock(bo->base.resv);
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
>
> lret = dma_resv_wait_timeout_rcu(resv, true, interruptible,
> 30 * HZ);
> @@ -313,7 +313,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
> else if (lret == 0)
> return -EBUSY;
>
> - spin_lock(&ttm_glob.lru_lock);
> + spin_lock(&bo->bdev->lru_lock);
> if (unlock_resv && !dma_resv_trylock(bo->base.resv)) {
> /*
> * We raced, and lost, someone else holds the reservation now,
> @@ -323,7 +323,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
> * delayed destruction would succeed, so just return success
> * here.
> */
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
> return 0;
> }
> ret = 0;
> @@ -332,13 +332,13 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
> if (ret || unlikely(list_empty(&bo->ddestroy))) {
> if (unlock_resv)
> dma_resv_unlock(bo->base.resv);
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
> return ret;
> }
>
> ttm_bo_del_from_lru(bo);
> list_del_init(&bo->ddestroy);
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
> ttm_bo_cleanup_memtype_use(bo);
>
> if (unlock_resv)
> @@ -355,13 +355,12 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
> */
> bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all)
> {
> - struct ttm_global *glob = &ttm_glob;
> struct list_head removed;
> bool empty;
>
> INIT_LIST_HEAD(&removed);
>
> - spin_lock(&glob->lru_lock);
> + spin_lock(&bdev->lru_lock);
> while (!list_empty(&bdev->ddestroy)) {
> struct ttm_buffer_object *bo;
>
> @@ -372,24 +371,24 @@ bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all)
> continue;
>
> if (remove_all || bo->base.resv != &bo->base._resv) {
> - spin_unlock(&glob->lru_lock);
> + spin_unlock(&bdev->lru_lock);
> dma_resv_lock(bo->base.resv, NULL);
>
> - spin_lock(&glob->lru_lock);
> + spin_lock(&bdev->lru_lock);
> ttm_bo_cleanup_refs(bo, false, !remove_all, true);
>
> } else if (dma_resv_trylock(bo->base.resv)) {
> ttm_bo_cleanup_refs(bo, false, !remove_all, true);
> } else {
> - spin_unlock(&glob->lru_lock);
> + spin_unlock(&bdev->lru_lock);
> }
>
> ttm_bo_put(bo);
> - spin_lock(&glob->lru_lock);
> + spin_lock(&bdev->lru_lock);
> }
> list_splice_tail(&removed, &bdev->ddestroy);
> empty = list_empty(&bdev->ddestroy);
> - spin_unlock(&glob->lru_lock);
> + spin_unlock(&bdev->lru_lock);
>
> return empty;
> }
> @@ -424,7 +423,7 @@ static void ttm_bo_release(struct kref *kref)
> ttm_bo_flush_all_fences(bo);
> bo->deleted = true;
>
> - spin_lock(&ttm_glob.lru_lock);
> + spin_lock(&bo->bdev->lru_lock);
>
> /*
> * Make pinned bos immediately available to
> @@ -438,17 +437,17 @@ static void ttm_bo_release(struct kref *kref)
>
> kref_init(&bo->kref);
> list_add_tail(&bo->ddestroy, &bdev->ddestroy);
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
>
> schedule_delayed_work(&bdev->wq,
> ((HZ / 100) < 1) ? 1 : HZ / 100);
> return;
> }
>
> - spin_lock(&ttm_glob.lru_lock);
> + spin_lock(&bo->bdev->lru_lock);
> ttm_bo_del_from_lru(bo);
> list_del(&bo->ddestroy);
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
>
> ttm_bo_cleanup_memtype_use(bo);
> dma_resv_unlock(bo->base.resv);
> @@ -622,7 +621,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
> unsigned i;
> int ret;
>
> - spin_lock(&ttm_glob.lru_lock);
> + spin_lock(&bo->bdev->lru_lock);
> for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
> list_for_each_entry(bo, &man->lru[i], lru) {
> bool busy;
> @@ -659,7 +658,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
> if (!bo) {
> if (busy_bo && !ttm_bo_get_unless_zero(busy_bo))
> busy_bo = NULL;
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
> ret = ttm_mem_evict_wait_busy(busy_bo, ctx, ticket);
> if (busy_bo)
> ttm_bo_put(busy_bo);
> @@ -673,7 +672,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
> return ret;
> }
>
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
>
> ret = ttm_bo_evict(bo, ctx);
> if (locked)
> @@ -773,10 +772,9 @@ static int ttm_bo_mem_placement(struct ttm_buffer_object *bo,
> mem->mem_type = place->mem_type;
> mem->placement = place->flags;
>
> - spin_lock(&ttm_glob.lru_lock);
> + spin_lock(&bo->bdev->lru_lock);
> ttm_bo_move_to_lru_tail(bo, mem, NULL);
> - spin_unlock(&ttm_glob.lru_lock);
> -
> + spin_unlock(&bo->bdev->lru_lock);
> return 0;
> }
>
> @@ -1160,7 +1158,6 @@ EXPORT_SYMBOL(ttm_bo_wait);
> int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
> gfp_t gfp_flags)
> {
> - struct ttm_global *glob = &ttm_glob;
> bool locked;
> int ret;
>
> @@ -1185,7 +1182,7 @@ int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
>
> ttm_bo_del_from_lru(bo);
> /* TODO: Cleanup the locking */
> - spin_unlock(&glob->lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
>
> /*
> * Move to system cached
> diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
> index 2c280fb1e992..924d892109e8 100644
> --- a/drivers/gpu/drm/ttm/ttm_device.c
> +++ b/drivers/gpu/drm/ttm/ttm_device.c
> @@ -81,7 +81,6 @@ static int ttm_global_init(void)
> ttm_pool_mgr_init(num_pages * 50 / 100);
> ttm_tt_mgr_init();
>
> - spin_lock_init(&glob->lru_lock);
> glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);
>
> if (unlikely(glob->dummy_read_page == NULL)) {
> @@ -125,13 +124,12 @@ EXPORT_SYMBOL(ttm_global_swapout);
> long ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
> gfp_t gfp_flags)
> {
> - struct ttm_global *glob = &ttm_glob;
> struct ttm_resource_manager *man;
> struct ttm_buffer_object *bo;
> unsigned i, j;
> int ret;
>
> - spin_lock(&glob->lru_lock);
> + spin_lock(&bdev->lru_lock);
> for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
> man = ttm_manager_type(bdev, i);
> if (!man || !man->use_tt)
> @@ -156,7 +154,7 @@ long ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
> }
> }
> }
> - spin_unlock(&glob->lru_lock);
> + spin_unlock(&bdev->lru_lock);
> return 0;
> }
> EXPORT_SYMBOL(ttm_device_swapout);
> @@ -223,6 +221,7 @@ int ttm_device_init(struct ttm_device *bdev, struct ttm_device_funcs *funcs,
>
> bdev->vma_manager = vma_manager;
> INIT_DELAYED_WORK(&bdev->wq, ttm_device_delayed_workqueue);
> + spin_lock_init(&bdev->lru_lock);
> INIT_LIST_HEAD(&bdev->ddestroy);
> bdev->dev_mapping = mapping;
> mutex_lock(&ttm_global_mutex);
> @@ -235,7 +234,6 @@ EXPORT_SYMBOL(ttm_device_init);
>
> void ttm_device_fini(struct ttm_device *bdev)
> {
> - struct ttm_global *glob = &ttm_glob;
> struct ttm_resource_manager *man;
> unsigned i;
>
> @@ -252,11 +250,11 @@ void ttm_device_fini(struct ttm_device *bdev)
> if (ttm_bo_delayed_delete(bdev, true))
> pr_debug("Delayed destroy list was clean\n");
>
> - spin_lock(&glob->lru_lock);
> + spin_lock(&bdev->lru_lock);
> for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
> if (list_empty(&man->lru[0]))
> pr_debug("Swap list %d was clean\n", i);
> - spin_unlock(&glob->lru_lock);
> + spin_unlock(&bdev->lru_lock);
>
> ttm_pool_fini(&bdev->pool);
> ttm_global_release();
> diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
> index 690ab97d52b7..071c48d672c6 100644
> --- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c
> +++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c
> @@ -51,14 +51,12 @@ void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
> if (list_empty(list))
> return;
>
> - spin_lock(&ttm_glob.lru_lock);
> list_for_each_entry(entry, list, head) {
> struct ttm_buffer_object *bo = entry->bo;
>
> - ttm_bo_move_to_lru_tail(bo, &bo->mem, NULL);
> + ttm_bo_move_to_lru_tail_unlocked(bo);
> dma_resv_unlock(bo->base.resv);
> }
> - spin_unlock(&ttm_glob.lru_lock);
>
> if (ticket)
> ww_acquire_fini(ticket);
> @@ -154,7 +152,6 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
> if (list_empty(list))
> return;
>
> - spin_lock(&ttm_glob.lru_lock);
> list_for_each_entry(entry, list, head) {
> struct ttm_buffer_object *bo = entry->bo;
>
> @@ -162,10 +159,9 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
> dma_resv_add_shared_fence(bo->base.resv, fence);
> else
> dma_resv_add_excl_fence(bo->base.resv, fence);
> - ttm_bo_move_to_lru_tail(bo, &bo->mem, NULL);
> + ttm_bo_move_to_lru_tail_unlocked(bo);
> dma_resv_unlock(bo->base.resv);
> }
> - spin_unlock(&ttm_glob.lru_lock);
> if (ticket)
> ww_acquire_fini(ticket);
> }
> diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
> index ed1672a9f332..04f2eef653ab 100644
> --- a/drivers/gpu/drm/ttm/ttm_resource.c
> +++ b/drivers/gpu/drm/ttm/ttm_resource.c
> @@ -91,7 +91,6 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev,
> .no_wait_gpu = false,
> .force_alloc = true
> };
> - struct ttm_global *glob = &ttm_glob;
> struct dma_fence *fence;
> int ret;
> unsigned i;
> @@ -100,18 +99,18 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev,
> * Can't use standard list traversal since we're unlocking.
> */
>
> - spin_lock(&glob->lru_lock);
> + spin_lock(&bdev->lru_lock);
> for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
> while (!list_empty(&man->lru[i])) {
> - spin_unlock(&glob->lru_lock);
> + spin_unlock(&bdev->lru_lock);
> ret = ttm_mem_evict_first(bdev, man, NULL, &ctx,
> NULL);
> if (ret)
> return ret;
> - spin_lock(&glob->lru_lock);
> + spin_lock(&bdev->lru_lock);
> }
> }
> - spin_unlock(&glob->lru_lock);
> + spin_unlock(&bdev->lru_lock);
>
> spin_lock(&man->move_lock);
> fence = dma_fence_get(man->move);
> diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
> index d007feef7676..dbccac957f8f 100644
> --- a/include/drm/ttm/ttm_bo_driver.h
> +++ b/include/drm/ttm/ttm_bo_driver.h
> @@ -180,9 +180,9 @@ static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
> static inline void
> ttm_bo_move_to_lru_tail_unlocked(struct ttm_buffer_object *bo)
> {
> - spin_lock(&ttm_glob.lru_lock);
> + spin_lock(&bo->bdev->lru_lock);
> ttm_bo_move_to_lru_tail(bo, &bo->mem, NULL);
> - spin_unlock(&ttm_glob.lru_lock);
> + spin_unlock(&bo->bdev->lru_lock);
> }
>
> static inline void ttm_bo_assign_mem(struct ttm_buffer_object *bo,
> diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h
> index cda6efb4c34b..bae56d29e8ff 100644
> --- a/include/drm/ttm/ttm_device.h
> +++ b/include/drm/ttm/ttm_device.h
> @@ -56,7 +56,6 @@ extern struct ttm_global {
> */
>
> struct page *dummy_read_page;
> - spinlock_t lru_lock;
>
> /**
> * Protected by ttm_global_mutex.
> @@ -277,8 +276,9 @@ struct ttm_device {
> struct ttm_pool pool;
>
> /*
> - * Protected by the global:lru lock.
> + * Protection for the per manager LRU and ddestroy lists.
> */
> + spinlock_t lru_lock;
> struct list_head ddestroy;
>
> /*
> --
> 2.25.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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