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/radeon/radeon_mn.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/radeon/radeon_mn.c b/drivers/gpu/drm/radeon/radeon_mn.c index b3019505065a..f77294f58e63 100644 --- a/drivers/gpu/drm/radeon/radeon_mn.c +++ b/drivers/gpu/drm/radeon/radeon_mn.c @@ -124,6 +124,7 @@ static int radeon_mn_invalidate_range_start(struct mmu_notifier *mn, struct radeon_mn *rmn = container_of(mn, struct radeon_mn, mn); struct ttm_operation_ctx ctx = { false, false }; struct interval_tree_node *it; + bool update_to_read_only; unsigned long end; int ret = 0; @@ -138,6 +139,8 @@ static int radeon_mn_invalidate_range_start(struct mmu_notifier *mn, else if (!mutex_trylock(&rmn->lock)) return -EAGAIN; + update_to_read_only = mmu_notifier_range_update_to_read_only(range); + it = interval_tree_iter_first(&rmn->objects, range->start, end); while (it) { struct radeon_mn_node *node; @@ -153,10 +156,20 @@ static int radeon_mn_invalidate_range_start(struct mmu_notifier *mn, it = interval_tree_iter_next(it, range->start, end); list_for_each_entry(bo, &node->bos, mn_list) { + bool read_only; if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound) continue; + /* + * 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 = radeon_ttm_tt_is_readonly(bo->tbo.ttm); + if (update_to_read_only && read_only) + continue; + r = radeon_bo_reserve(bo, true); if (r) { DRM_ERROR("(%ld) failed to reserve user bo\n", r); -- 2.17.2
