On 2018-09-13 10:55 a.m., Christian König wrote:
> Am 13.09.2018 um 10:35 schrieb Michel Dänzer:
>> [ Moving to dri-devel, where TTM patches are reviewed ]
>>
>> On 2018-09-12 9:23 p.m., Christian König wrote:
>>> While cutting the lists we sometimes accidentally added a list_head from
>>> the stack to the LRUs, effectively corrupting the list.
>>>
>>> Remove the list cutting and use explicit list manipulation instead.
>>>
>>> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
>>> ---
>>> drivers/gpu/drm/ttm/ttm_bo.c | 51
>>> ++++++++++++++++++++++++++------------------
>>> 1 file changed, 30 insertions(+), 21 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
>>> index 138c98902033..b2a33bf1ef10 100644
>>> --- a/drivers/gpu/drm/ttm/ttm_bo.c
>>> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
>>> @@ -247,23 +247,18 @@ void ttm_bo_move_to_lru_tail(struct
>>> ttm_buffer_object *bo,
>>> }
>>> EXPORT_SYMBOL(ttm_bo_move_to_lru_tail);
>>> -static void ttm_bo_bulk_move_helper(struct ttm_lru_bulk_move_pos
>>> *pos,
>>> - struct list_head *lru, bool is_swap)
>>> +static void ttm_list_move_bulk_tail(struct list_head *list,
>>> + struct list_head *first,
>>> + struct list_head *last)
>>> {
>>> - struct list_head *list;
>>> - LIST_HEAD(entries);
>>> - LIST_HEAD(before);
>>> + first->prev->next = last->next;
>>> + last->next->prev = first->prev;
>>> - reservation_object_assert_held(pos->last->resv);
>>> - list = is_swap ? &pos->last->swap : &pos->last->lru;
>>> - list_cut_position(&entries, lru, list);
>>> + list->prev->next = first;
>>> + first->prev = list->prev;
>>> - reservation_object_assert_held(pos->first->resv);
>>> - list = is_swap ? pos->first->swap.prev : pos->first->lru.prev;
>>> - list_cut_position(&before, &entries, list);
>>> -
>>> - list_splice(&before, lru);
>>> - list_splice_tail(&entries, lru);
>>> + last->next = list;
>>> + list->prev = last;
>>> }
>>> void ttm_bo_bulk_move_lru_tail(struct ttm_lru_bulk_move *bulk)
>>> @@ -271,23 +266,33 @@ void ttm_bo_bulk_move_lru_tail(struct
>>> ttm_lru_bulk_move *bulk)
>>> unsigned i;
>>> for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
>>> + struct ttm_lru_bulk_move_pos *pos = &bulk->tt[i];
>>> struct ttm_mem_type_manager *man;
>>> - if (!bulk->tt[i].first)
>>> + if (!pos->first)
>>> continue;
>>> - man = &bulk->tt[i].first->bdev->man[TTM_PL_TT];
>>> - ttm_bo_bulk_move_helper(&bulk->tt[i], &man->lru[i], false);
>>> + reservation_object_assert_held(pos->first->resv);
>>> + reservation_object_assert_held(pos->last->resv);
>>> +
>>> + man = &pos->first->bdev->man[TTM_PL_TT];
>>> + ttm_list_move_bulk_tail(&man->lru[i], &pos->first->lru,
>>> + &pos->last->lru);
>>> }
>>> for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
>>> + struct ttm_lru_bulk_move_pos *pos = &bulk->vram[i];
>>> struct ttm_mem_type_manager *man;
>>> - if (!bulk->vram[i].first)
>>> + if (!pos->first)
>>> continue;
>>> - man = &bulk->vram[i].first->bdev->man[TTM_PL_VRAM];
>>> - ttm_bo_bulk_move_helper(&bulk->vram[i], &man->lru[i], false);
>>> + reservation_object_assert_held(pos->first->resv);
>>> + reservation_object_assert_held(pos->last->resv);
>>> +
>>> + man = &pos->first->bdev->man[TTM_PL_VRAM];
>>> + ttm_list_move_bulk_tail(&man->lru[i], &pos->first->lru,
>>> + &pos->last->lru);
>>> }
>>> for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
>>> @@ -297,8 +302,12 @@ void ttm_bo_bulk_move_lru_tail(struct
>>> ttm_lru_bulk_move *bulk)
>>> if (!pos->first)
>>> continue;
>>> + reservation_object_assert_held(pos->first->resv);
>>> + reservation_object_assert_held(pos->last->resv);
>>> +
>>> lru = &pos->first->bdev->glob->swap_lru[i];
>>> - ttm_bo_bulk_move_helper(&bulk->swap[i], lru, true);
>>> + ttm_list_move_bulk_tail(lru, &pos->first->swap,
>>> + &pos->last->swap);
>>> }
>>> }
>>> EXPORT_SYMBOL(ttm_bo_bulk_move_lru_tail);
>>>
>> Seems like more code could be kept in / moved into the shared helper
>> function. That would keep the ttm_bo_bulk_move_lru_tail code leaner, and
>> might make the helper function changes easier to review as well.
>
> Yeah, actually only wanted to send that to Rui and you for testing.
>
> Going to clean that up and send it for upstream review today.
Sounds good, but Tom needs to test it as well.
--
Earthling Michel Dänzer | http://www.amd.com
Libre software enthusiast | Mesa and X developer
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