回复: [PATCH] drm/amdgpu: New method to check block continuous

[Pan, Xinhui]

[AMD Official Use Only - General]

What I am thinking is that
Hi Chris,

For continuous memory allocation, of course the blocks are in ascending order.

For non-continuous memory allocation, the allocated memory might be continuous while the blocks are not in ascending order.

Anyway, could we just re-sort these blocks in ascending order if memory is indeed continuous?

thanks
xinhui

________________________________________
发件人: Christian König <ckoenig.leichtzumerken at gmail.com>
发送时间: 2022年11月29日 1:11
收件人: Pan, Xinhui; amd-gfx at lists.freedesktop.org
抄送: Deucher, Alexander
主题: Re: [PATCH] drm/amdgpu: New method to check block continuous

Am 27.11.22 um 06:39 schrieb xinhui pan:
> Blocks are not guarnteed to be in ascending order.

Well certainly a NAK. Blocks are required to be in ascending order to be
contiguous.

Regards,
Christian.

>
> Signed-off-by: xinhui pan <xinhui.pan at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 21 ++++++++------------
>   1 file changed, 8 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index 27159f1d112e..17175d284869 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -59,22 +59,17 @@ amdgpu_vram_mgr_first_block(struct list_head *list)
>   static inline bool amdgpu_is_vram_mgr_blocks_contiguous(struct list_head *head)
>   {
>       struct drm_buddy_block *block;
> -     u64 start, size;
> +     u64 start = LONG_MAX, end = 0, size = 0;
>
> -     block = amdgpu_vram_mgr_first_block(head);
> -     if (!block)
> -             return false;
> +     list_for_each_entry(block, head, link) {
> +             u64 bstart = amdgpu_vram_mgr_block_start(block);
> +             u64 bsize = amdgpu_vram_mgr_block_size(block);
>
> -     while (head != block->link.next) {
> -             start = amdgpu_vram_mgr_block_start(block);
> -             size = amdgpu_vram_mgr_block_size(block);
> -
> -             block = list_entry(block->link.next, struct drm_buddy_block, link);
> -             if (start + size != amdgpu_vram_mgr_block_start(block))
> -                     return false;
> +             start = min(bstart, start);
> +             end = max(bstart + bsize, end);
> +             size += bsize;
>       }
> -
> -     return true;
> +     return end == start + size;
>   }
>
>

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