On 11/12/2012 03:00 PM, Maarten Lankhorst wrote:
> Just use the return error from ttm_mem_evict_first instead.
Here driver need to be able to evict a memory type completely, because
they might shut down
the memory type or clear it for some legacy usage, suspending or
whatever, so returning 0 on -EBUSY isn't sufficient,
we need at least a list empty check, and a shared reservation at this
point is illegal.
This is a point where the mechanism to exclude other reservers is
needed, as we discussed previously.
vmwgfx is using the ttm lock, but will of course adapt if a new
mechanism is emerging.
Thanks,
/Thomas
>
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com>
> ---
> drivers/gpu/drm/ttm/ttm_bo.c | 27 ++++++++-------------------
> 1 file changed, 8 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 74d6e7c..a3383a7 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -1302,29 +1302,18 @@ EXPORT_SYMBOL(ttm_bo_create);
> static int ttm_bo_force_list_clean(struct ttm_bo_device *bdev,
> unsigned mem_type, bool allow_errors)
> {
> - struct ttm_mem_type_manager *man = &bdev->man[mem_type];
> - struct ttm_bo_global *glob = bdev->glob;
> - int ret;
> -
> - /*
> - * Can't use standard list traversal since we're unlocking.
> - */
> + int ret = 0;
>
> - spin_lock(&glob->lru_lock);
> - while (!list_empty(&man->lru)) {
> - spin_unlock(&glob->lru_lock);
> + while (!ret) {
> ret = ttm_mem_evict_first(bdev, mem_type, false, false, false);
> - if (ret) {
> - if (allow_errors) {
> - return ret;
> - } else {
> - pr_err("Cleanup eviction failed\n");
> - }
> + if (ret == -EBUSY)
> + return 0;
> + else if (ret && !allow_errors) {
> + pr_err("Cleanup eviction failed\n");
> + ret = 0;
> }
> - spin_lock(&glob->lru_lock);
> }
> - spin_unlock(&glob->lru_lock);
> - return 0;
> + return ret;
> }
>
> int ttm_bo_clean_mm(struct ttm_bo_device *bdev, unsigned mem_type)
