If no reservation ticket is given to the execbuf reservation utilities, try reservation with non-blocking semantics. This is intended for eviction paths that use the execbuf reservation utilities for convenience rather than for deadlock avoidance.
Signed-off-by: Thomas Hellstrom thellstrom@vmware.com --- drivers/gpu/drm/ttm/ttm_execbuf_util.c | 32 +++++++++++++++++++------------- include/drm/ttm/ttm_execbuf_util.h | 3 ++- 2 files changed, 21 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c index 6c91178..479e941 100644 --- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c +++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c @@ -32,8 +32,7 @@ #include <linux/sched.h> #include <linux/module.h>
-static void ttm_eu_backoff_reservation_locked(struct list_head *list, - struct ww_acquire_ctx *ticket) +static void ttm_eu_backoff_reservation_locked(struct list_head *list) { struct ttm_validate_buffer *entry;
@@ -93,8 +92,9 @@ void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket, entry = list_first_entry(list, struct ttm_validate_buffer, head); glob = entry->bo->glob; spin_lock(&glob->lru_lock); - ttm_eu_backoff_reservation_locked(list, ticket); - ww_acquire_fini(ticket); + ttm_eu_backoff_reservation_locked(list); + if (ticket) + ww_acquire_fini(ticket); spin_unlock(&glob->lru_lock); } EXPORT_SYMBOL(ttm_eu_backoff_reservation); @@ -130,7 +130,8 @@ int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket, entry = list_first_entry(list, struct ttm_validate_buffer, head); glob = entry->bo->glob;
- ww_acquire_init(ticket, &reservation_ww_class); + if (ticket) + ww_acquire_init(ticket, &reservation_ww_class); retry: list_for_each_entry(entry, list, head) { struct ttm_buffer_object *bo = entry->bo; @@ -139,16 +140,17 @@ retry: if (entry->reserved) continue;
- - ret = ttm_bo_reserve_nolru(bo, true, false, true, ticket); + ret = ttm_bo_reserve_nolru(bo, true, (ticket == NULL), true, + ticket);
if (ret == -EDEADLK) { /* uh oh, we lost out, drop every reservation and try * to only reserve this buffer, then start over if * this succeeds. */ + BUG_ON(ticket == NULL); spin_lock(&glob->lru_lock); - ttm_eu_backoff_reservation_locked(list, ticket); + ttm_eu_backoff_reservation_locked(list); spin_unlock(&glob->lru_lock); ttm_eu_list_ref_sub(list); ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, @@ -175,7 +177,8 @@ retry: } }
- ww_acquire_done(ticket); + if (ticket) + ww_acquire_done(ticket); spin_lock(&glob->lru_lock); ttm_eu_del_from_lru_locked(list); spin_unlock(&glob->lru_lock); @@ -184,12 +187,14 @@ retry:
err: spin_lock(&glob->lru_lock); - ttm_eu_backoff_reservation_locked(list, ticket); + ttm_eu_backoff_reservation_locked(list); spin_unlock(&glob->lru_lock); ttm_eu_list_ref_sub(list); err_fini: - ww_acquire_done(ticket); - ww_acquire_fini(ticket); + if (ticket) { + ww_acquire_done(ticket); + ww_acquire_fini(ticket); + } return ret; } EXPORT_SYMBOL(ttm_eu_reserve_buffers); @@ -224,7 +229,8 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket, } spin_unlock(&bdev->fence_lock); spin_unlock(&glob->lru_lock); - ww_acquire_fini(ticket); + if (ticket) + ww_acquire_fini(ticket);
list_for_each_entry(entry, list, head) { if (entry->old_sync_obj) diff --git a/include/drm/ttm/ttm_execbuf_util.h b/include/drm/ttm/ttm_execbuf_util.h index ec8a1d3..16db7d0 100644 --- a/include/drm/ttm/ttm_execbuf_util.h +++ b/include/drm/ttm/ttm_execbuf_util.h @@ -70,7 +70,8 @@ extern void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket, /** * function ttm_eu_reserve_buffers * - * @ticket: [out] ww_acquire_ctx returned by call. + * @ticket: [out] ww_acquire_ctx filled in by call, or NULL if only + * non-blocking reserves should be tried. * @list: thread private list of ttm_validate_buffer structs. * * Tries to reserve bos pointed to by the list entries for validation.