[PATCH v2] drm/amdkfd: handle errors from svm validate and map
Chen, Xiaogang
xiaogang.chen at amd.com
Fri Sep 15 21:06:07 UTC 2023
On 9/15/2023 8:28 AM, Philip Yang wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
>
>
> If new range is splited to multiple pranges with max_svm_range_pages
> alignment and added to update_list, svm validate and map should keep
> going after error to make sure maps_to_gpu flag is up to date for the
> whole range.
>
> svm validate and map update set prange->mapped_to_gpu after mapping to
> GPUs successfully, otherwise clear prange->mapped_to_gpu flag (for
> update mapping case) instead of setting error flag, we can remove
> the redundant error flag to simpliy code.
>
> Update prange->mapped_to_gpu flag inside svm_range_lock, to guarant we
> always set prange invalid flag to evict queues or unmap from GPUs before
> the system memory is moved.
>
> After svm validate and map return error, the caller retry will update
> the mapping for the whole range.
>
> Fixes: c22b04407097 ("drm/amdkfd: flag added to handle errors from svm validate and map")
> Signed-off-by: Philip Yang <Philip.Yang at amd.com>
> ---
> drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 18 ++++++++----------
> drivers/gpu/drm/amd/amdkfd/kfd_svm.h | 1 -
> 2 files changed, 8 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> index 5d7ba7dbf6ce..26018b1d6138 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
> @@ -818,7 +818,7 @@ svm_range_is_same_attrs(struct kfd_process *p, struct svm_range *prange,
> }
> }
>
> - return !prange->is_error_flag;
> + return true;
> }
>
> /**
> @@ -1724,20 +1724,17 @@ static int svm_range_validate_and_map(struct mm_struct *mm,
> ctx->bitmap, wait, flush_tlb);
>
> unlock_out:
> + prange->mapped_to_gpu = !r;
I do not understand why set prange->mapped_to_gpu here? It handles one
vma, not for all prange. If there are multiple vma and first vma handle
is ok, and second vma handle fail at amdgpu_hmm_range_get_pages or
svm_range_dma_map, you would get prange->mapped_to_gpu be true, but only
part of pragne got mapped, right?
Regards
Xiaogang
> svm_range_unlock(prange);
>
> addr = next;
> }
>
> - if (addr == end) {
> + if (addr == end)
> prange->validated_once = true;
> - prange->mapped_to_gpu = true;
> - }
>
> unreserve_out:
> svm_range_unreserve_bos(ctx);
> -
> - prange->is_error_flag = !!r;
> if (!r)
> prange->validate_timestamp = ktime_get_boottime();
>
> @@ -2106,7 +2103,8 @@ svm_range_add(struct kfd_process *p, uint64_t start, uint64_t size,
> next = interval_tree_iter_next(node, start, last);
> next_start = min(node->last, last) + 1;
>
> - if (svm_range_is_same_attrs(p, prange, nattr, attrs)) {
> + if (svm_range_is_same_attrs(p, prange, nattr, attrs) &&
> + prange->mapped_to_gpu) {
> /* nothing to do */
> } else if (node->start < start || node->last > last) {
> /* node intersects the update range and its attributes
> @@ -3519,7 +3517,7 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
> struct svm_range *next;
> bool update_mapping = false;
> bool flush_tlb;
> - int r = 0;
> + int r, ret = 0;
>
> pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] pages 0x%llx\n",
> p->pasid, &p->svms, start, start + size - 1, size);
> @@ -3607,7 +3605,7 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
> out_unlock_range:
> mutex_unlock(&prange->migrate_mutex);
> if (r)
> - break;
> + ret = r;
> }
>
> dynamic_svm_range_dump(svms);
> @@ -3620,7 +3618,7 @@ svm_range_set_attr(struct kfd_process *p, struct mm_struct *mm,
> pr_debug("pasid 0x%x svms 0x%p [0x%llx 0x%llx] done, r=%d\n", p->pasid,
> &p->svms, start, start + size - 1, r);
>
> - return r;
> + return ret ? ret : r;
> }
>
> static int
> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.h b/drivers/gpu/drm/amd/amdkfd/kfd_svm.h
> index 9e668eeefb32..91715bf3233c 100644
> --- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.h
> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.h
> @@ -134,7 +134,6 @@ struct svm_range {
> DECLARE_BITMAP(bitmap_aip, MAX_GPU_INSTANCE);
> bool validated_once;
> bool mapped_to_gpu;
> - bool is_error_flag;
> };
>
> static inline void svm_range_lock(struct svm_range *prange)
> --
> 2.35.1
>
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