From d6ea88865d3e5b0c62040531310c1f2c6a994f46 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Mon, 22 Nov 2010 13:24:40 +1000 Subject: drm/ttm: Add a bo list reserve fastpath (v2) Makes it possible to reserve a list of buffer objects with a single spin lock / unlock if there is no contention. Should improve cpu usage on SMP kernels. v2: Initialize private list members on reserve and don't call ttm_bo_list_ref_sub() with zero put_count. Signed-off-by: Thomas Hellstrom Signed-off-by: Dave Airlie --- drivers/gpu/drm/ttm/ttm_bo.c | 32 ++++----- drivers/gpu/drm/ttm/ttm_execbuf_util.c | 124 ++++++++++++++++++++++++++++++--- 2 files changed, 129 insertions(+), 27 deletions(-) (limited to 'drivers/gpu/drm/ttm') diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 148a322d8f5..a586378b1b2 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -169,7 +169,7 @@ int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo, bool interruptible) } EXPORT_SYMBOL(ttm_bo_wait_unreserved); -static void ttm_bo_add_to_lru(struct ttm_buffer_object *bo) +void ttm_bo_add_to_lru(struct ttm_buffer_object *bo) { struct ttm_bo_device *bdev = bo->bdev; struct ttm_mem_type_manager *man; @@ -191,11 +191,7 @@ static void ttm_bo_add_to_lru(struct ttm_buffer_object *bo) } } -/** - * Call with the lru_lock held. - */ - -static int ttm_bo_del_from_lru(struct ttm_buffer_object *bo) +int ttm_bo_del_from_lru(struct ttm_buffer_object *bo) { int put_count = 0; @@ -267,6 +263,15 @@ static void ttm_bo_ref_bug(struct kref *list_kref) BUG(); } +void ttm_bo_list_ref_sub(struct ttm_buffer_object *bo, int count, + bool never_free) +{ + while (count--) + kref_put(&bo->list_kref, + (never_free || (count >= 0)) ? ttm_bo_ref_bug : + ttm_bo_release_list); +} + int ttm_bo_reserve(struct ttm_buffer_object *bo, bool interruptible, bool no_wait, bool use_sequence, uint32_t sequence) @@ -282,8 +287,7 @@ int ttm_bo_reserve(struct ttm_buffer_object *bo, put_count = ttm_bo_del_from_lru(bo); spin_unlock(&glob->lru_lock); - while (put_count--) - kref_put(&bo->list_kref, ttm_bo_ref_bug); + ttm_bo_list_ref_sub(bo, put_count, true); return ret; } @@ -496,8 +500,7 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo) spin_unlock(&glob->lru_lock); ttm_bo_cleanup_memtype_use(bo); - while (put_count--) - kref_put(&bo->list_kref, ttm_bo_ref_bug); + ttm_bo_list_ref_sub(bo, put_count, true); return; } else { @@ -580,8 +583,7 @@ retry: spin_unlock(&glob->lru_lock); ttm_bo_cleanup_memtype_use(bo); - while (put_count--) - kref_put(&bo->list_kref, ttm_bo_ref_bug); + ttm_bo_list_ref_sub(bo, put_count, true); return 0; } @@ -802,8 +804,7 @@ retry: BUG_ON(ret != 0); - while (put_count--) - kref_put(&bo->list_kref, ttm_bo_ref_bug); + ttm_bo_list_ref_sub(bo, put_count, true); ret = ttm_bo_evict(bo, interruptible, no_wait_reserve, no_wait_gpu); ttm_bo_unreserve(bo); @@ -1783,8 +1784,7 @@ static int ttm_bo_swapout(struct ttm_mem_shrink *shrink) put_count = ttm_bo_del_from_lru(bo); spin_unlock(&glob->lru_lock); - while (put_count--) - kref_put(&bo->list_kref, ttm_bo_ref_bug); + ttm_bo_list_ref_sub(bo, put_count, true); /** * Wait for GPU, then move to system cached. diff --git a/drivers/gpu/drm/ttm/ttm_execbuf_util.c b/drivers/gpu/drm/ttm/ttm_execbuf_util.c index c285c2902d1..201a71d111e 100644 --- a/drivers/gpu/drm/ttm/ttm_execbuf_util.c +++ b/drivers/gpu/drm/ttm/ttm_execbuf_util.c @@ -32,6 +32,72 @@ #include #include +static void ttm_eu_backoff_reservation_locked(struct list_head *list) +{ + struct ttm_validate_buffer *entry; + + list_for_each_entry(entry, list, head) { + struct ttm_buffer_object *bo = entry->bo; + if (!entry->reserved) + continue; + + if (entry->removed) { + ttm_bo_add_to_lru(bo); + entry->removed = false; + + } + entry->reserved = false; + atomic_set(&bo->reserved, 0); + wake_up_all(&bo->event_queue); + } +} + +static void ttm_eu_del_from_lru_locked(struct list_head *list) +{ + struct ttm_validate_buffer *entry; + + list_for_each_entry(entry, list, head) { + struct ttm_buffer_object *bo = entry->bo; + if (!entry->reserved) + continue; + + if (!entry->removed) { + entry->put_count = ttm_bo_del_from_lru(bo); + entry->removed = true; + } + } +} + +static void ttm_eu_list_ref_sub(struct list_head *list) +{ + struct ttm_validate_buffer *entry; + + list_for_each_entry(entry, list, head) { + struct ttm_buffer_object *bo = entry->bo; + + if (entry->put_count) { + ttm_bo_list_ref_sub(bo, entry->put_count, true); + entry->put_count = 0; + } + } +} + +static int ttm_eu_wait_unreserved_locked(struct list_head *list, + struct ttm_buffer_object *bo) +{ + struct ttm_bo_global *glob = bo->glob; + int ret; + + ttm_eu_del_from_lru_locked(list); + spin_unlock(&glob->lru_lock); + ret = ttm_bo_wait_unreserved(bo, true); + spin_lock(&glob->lru_lock); + if (unlikely(ret != 0)) + ttm_eu_backoff_reservation_locked(list); + return ret; +} + + void ttm_eu_backoff_reservation(struct list_head *list) { struct ttm_validate_buffer *entry; @@ -61,35 +127,71 @@ EXPORT_SYMBOL(ttm_eu_backoff_reservation); int ttm_eu_reserve_buffers(struct list_head *list, uint32_t val_seq) { + struct ttm_bo_global *glob; struct ttm_validate_buffer *entry; int ret; + if (list_empty(list)) + return 0; + + list_for_each_entry(entry, list, head) { + entry->reserved = false; + entry->put_count = 0; + entry->removed = false; + } + + entry = list_first_entry(list, struct ttm_validate_buffer, head); + glob = entry->bo->glob; + retry: + spin_lock(&glob->lru_lock); list_for_each_entry(entry, list, head) { struct ttm_buffer_object *bo = entry->bo; - entry->reserved = false; - ret = ttm_bo_reserve(bo, true, false, true, val_seq); - if (ret != 0) { - ttm_eu_backoff_reservation(list); - if (ret == -EAGAIN) { - ret = ttm_bo_wait_unreserved(bo, true); - if (unlikely(ret != 0)) - return ret; - goto retry; - } else +retry_this_bo: + ret = ttm_bo_reserve_locked(bo, true, true, true, val_seq); + switch (ret) { + case 0: + break; + case -EBUSY: + ret = ttm_eu_wait_unreserved_locked(list, bo); + if (unlikely(ret != 0)) { + spin_unlock(&glob->lru_lock); + ttm_eu_list_ref_sub(list); + return ret; + } + goto retry_this_bo; + case -EAGAIN: + ttm_eu_backoff_reservation_locked(list); + spin_unlock(&glob->lru_lock); + ttm_eu_list_ref_sub(list); + ret = ttm_bo_wait_unreserved(bo, true); + if (unlikely(ret != 0)) return ret; + goto retry; + default: + ttm_eu_backoff_reservation_locked(list); + spin_unlock(&glob->lru_lock); + ttm_eu_list_ref_sub(list); + return ret; } entry->reserved = true; if (unlikely(atomic_read(&bo->cpu_writers) > 0)) { - ttm_eu_backoff_reservation(list); + ttm_eu_backoff_reservation_locked(list); + spin_unlock(&glob->lru_lock); + ttm_eu_list_ref_sub(list); ret = ttm_bo_wait_cpu(bo, false); if (ret) return ret; goto retry; } } + + ttm_eu_del_from_lru_locked(list); + spin_unlock(&glob->lru_lock); + ttm_eu_list_ref_sub(list); + return 0; } EXPORT_SYMBOL(ttm_eu_reserve_buffers); -- cgit v1.2.3-70-g09d2