From: Jérôme Glisse <[email protected]> When range of virtual address is updated read only and corresponding user ptr object are already read only it is pointless to do anything. Optimize this case out.
Signed-off-by: Jérôme Glisse <[email protected]> Cc: Christian König <[email protected]> Cc: Jan Kara <[email protected]> Cc: Felix Kuehling <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Ross Zwisler <[email protected]> Cc: Dan Williams <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Radim Krčmář <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Ralph Campbell <[email protected]> Cc: John Hubbard <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: Arnd Bergmann <[email protected]> --- drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c index 3e6823fdd939..7880eda064cd 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c @@ -294,6 +294,7 @@ static int amdgpu_mn_invalidate_range_start_hsa(struct mmu_notifier *mn, { struct amdgpu_mn *amn = container_of(mn, struct amdgpu_mn, mn); struct interval_tree_node *it; + bool update_to_read_only; unsigned long end; /* notification is exclusive, but interval is inclusive */ @@ -302,6 +303,8 @@ static int amdgpu_mn_invalidate_range_start_hsa(struct mmu_notifier *mn, if (amdgpu_mn_read_lock(amn, range->blockable)) return -EAGAIN; + update_to_read_only = mmu_notifier_range_update_to_read_only(range); + it = interval_tree_iter_first(&amn->objects, range->start, end); while (it) { struct amdgpu_mn_node *node; @@ -317,6 +320,16 @@ static int amdgpu_mn_invalidate_range_start_hsa(struct mmu_notifier *mn, list_for_each_entry(bo, &node->bos, mn_list) { struct kgd_mem *mem = bo->kfd_bo; + bool read_only; + + /* + * If it is already read only and we are updating to + * read only then we do not need to change anything. + * So save time and skip this one. + */ + read_only = amdgpu_ttm_tt_is_readonly(bo->tbo.ttm); + if (update_to_read_only && read_only) + continue; if (amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, range->start, -- 2.17.2
