[AMD Official Use Only - Internal Distribution Only]

Hi Chris,

Yes. I'll rework the patch. Thanks for your comments.

--Brs, Morris Zhang MLSE Linux ML SRDC Ext. 25147

-----Original Message----- From: Koenig, Christian Christian.Koenig@amd.com Sent: Wednesday, April 21, 2021 9:34 PM To: Zhang, Morris Shiwu.Zhang@amd.com; dri-devel@lists.freedesktop.org Subject: Re: [PATCH] drm/ttm: fix error handling if no BO can be swapped out

Am 20.04.21 um 16:32 schrieb Shiwu Zhang:

In case that all pre-allocated BOs are busy, just continue to populate BOs since likely half of system memory in total is still free.

Signed-off-by: Shiwu Zhang shiwu.zhang@amd.com

drivers/gpu/drm/ttm/ttm_device.c | 4 ++-- drivers/gpu/drm/ttm/ttm_tt.c | 2 ++ 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c index 1f2024164d72..0200709db9be 100644 --- a/drivers/gpu/drm/ttm/ttm_device.c +++ b/drivers/gpu/drm/ttm/ttm_device.c @@ -133,7 +133,7 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx, struct ttm_resource_manager *man; struct ttm_buffer_object *bo; unsigned i, j;

• int ret;

• int ret=-EBUSY;

  spin_lock(&bdev->lru_lock); for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) { @@ -161,7

+161,7 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx, } } spin_unlock(&bdev->lru_lock);

• return 0;

• return ret;

The function should return the number of pages swapped out. Returning 0 here is already perfectly ok.

} EXPORT_SYMBOL(ttm_device_swapout);

diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c index 48c407cff112..4e1e06a04428 100644 --- a/drivers/gpu/drm/ttm/ttm_tt.c +++ b/drivers/gpu/drm/ttm/ttm_tt.c @@ -329,6 +329,8 @@ int ttm_tt_populate(struct ttm_device *bdev, ttm_dma32_pages_limit) {

ret = ttm_global_swapout(ctx, GFP_KERNEL);

• if (ret == -EBUSY)
  

• 	break;
  

  if (ret < 0) goto error;

Here we should just have a check for ret == 0 instead of testing for -EBUSY.

Regards, Christian.

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