> 2021年6月15日 20:01，Christian König <ckoenig.leichtzumer...@gmail.com> 写道：
>
> Am 15.06.21 um 13:57 schrieb xinhui pan:
>> Amdgpu set SG flag in populate callback. So TTM still count pages in SG
>> BO.
>
> It's probably better to fix this instead. E.g. why does amdgpu modify the SG
> flag during populate and not during initial creation? That doesn't seem to
> make sense.
fair enough. Let me have a try.
No idea why we set SG flag in populate years ago.
>
> Christian.
>
>> One easy way to fix this is lets count pages after populate callback.
>>
>> We hit one issue that amdgpu alloc many SG BOs, but TTM try to do swap
>> again and again even if swapout does not swap SG BOs at all.
>>
>> Signed-off-by: xinhui pan <xinhui....@amd.com>
>> ---
>> drivers/gpu/drm/ttm/ttm_tt.c | 32 +++++++++++++-------------------
>> 1 file changed, 13 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
>> index a1a25410ec74..4fa0a8cd71c0 100644
>> --- a/drivers/gpu/drm/ttm/ttm_tt.c
>> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
>> @@ -317,13 +317,6 @@ int ttm_tt_populate(struct ttm_device *bdev,
>> if (ttm_tt_is_populated(ttm))
>> return 0;
>> - if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) {
>> - atomic_long_add(ttm->num_pages, &ttm_pages_allocated);
>> - if (bdev->pool.use_dma32)
>> - atomic_long_add(ttm->num_pages,
>> - &ttm_dma32_pages_allocated);
>> - }
>> -
>> while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit ||
>> atomic_long_read(&ttm_dma32_pages_allocated) >
>> ttm_dma32_pages_limit) {
>> @@ -342,6 +335,13 @@ int ttm_tt_populate(struct ttm_device *bdev,
>> if (ret)
>> goto error;
>> + if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) {
>> + atomic_long_add(ttm->num_pages, &ttm_pages_allocated);
>> + if (bdev->pool.use_dma32)
>> + atomic_long_add(ttm->num_pages,
>> + &ttm_dma32_pages_allocated);
>> + }
>> +
>> ttm_tt_add_mapping(bdev, ttm);
>> ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
>> if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
>> @@ -355,12 +355,6 @@ int ttm_tt_populate(struct ttm_device *bdev,
>> return 0;
>> error:
>> - if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) {
>> - atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
>> - if (bdev->pool.use_dma32)
>> - atomic_long_sub(ttm->num_pages,
>> - &ttm_dma32_pages_allocated);
>> - }
>> return ret;
>> }
>> EXPORT_SYMBOL(ttm_tt_populate);
>> @@ -384,12 +378,6 @@ void ttm_tt_unpopulate(struct ttm_device *bdev, struct
>> ttm_tt *ttm)
>> if (!ttm_tt_is_populated(ttm))
>> return;
>> - ttm_tt_clear_mapping(ttm);
>> - if (bdev->funcs->ttm_tt_unpopulate)
>> - bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
>> - else
>> - ttm_pool_free(&bdev->pool, ttm);
>> -
>> if (!(ttm->page_flags & TTM_PAGE_FLAG_SG)) {
>> atomic_long_sub(ttm->num_pages, &ttm_pages_allocated);
>> if (bdev->pool.use_dma32)
>> @@ -397,6 +385,12 @@ void ttm_tt_unpopulate(struct ttm_device *bdev, struct
>> ttm_tt *ttm)
>> &ttm_dma32_pages_allocated);
>> }
>> + ttm_tt_clear_mapping(ttm);
>> + if (bdev->funcs->ttm_tt_unpopulate)
>> + bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
>> + else
>> + ttm_pool_free(&bdev->pool, ttm);
>> +
>> ttm->page_flags &= ~TTM_PAGE_FLAG_PRIV_POPULATED;
>> }
>>
>
