| Message ID | 20240813094451.1478481-1-lincao12@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/buddy: fix issue that force_merge cannot free all roots | expand |
On 13/08/2024 10:44, Lin.Cao wrote: > If buddy manager have more than one roots and each root have sub-block > need to be free. When drm_buddy_fini called, the first loop of > force_merge will merge and free all of the sub block of first root, > which offset is 0x0 and size is biggest(more than have of the mm size). > In subsequent force_merge rounds, if we use 0 as start and use remaining > mm size as end, the block of other roots will be skipped in > __force_merge function. It will cause the other roots can not be freed. > > Solution: use roots' offset as the start could fix this issue. Were you able to take a look at the test side for this? See previous reply: https://lore.kernel.org/dri-devel/3fdd9175-832a-4113-8aaa-6039925c5a4d@intel.com/ Patch itself is good, but would be good to understand why the test for this is not failing, and try to improve that also. > > Signed-off-by: Lin.Cao <lincao12@amd.com> > --- > drivers/gpu/drm/drm_buddy.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c > index 94f8c34fc293..b3f0dd652088 100644 > --- a/drivers/gpu/drm/drm_buddy.c > +++ b/drivers/gpu/drm/drm_buddy.c > @@ -324,7 +324,7 @@ EXPORT_SYMBOL(drm_buddy_init); > */ > void drm_buddy_fini(struct drm_buddy *mm) > { > - u64 root_size, size; > + u64 root_size, size, start; > unsigned int order; > int i; > > @@ -332,7 +332,8 @@ void drm_buddy_fini(struct drm_buddy *mm) > > for (i = 0; i < mm->n_roots; ++i) { > order = ilog2(size) - ilog2(mm->chunk_size); > - __force_merge(mm, 0, size, order); > + start = drm_buddy_block_offset(mm->roots[i]); > + __force_merge(mm, start, start + size, order); > > WARN_ON(!drm_buddy_block_is_free(mm->roots[i])); > drm_block_free(mm, mm->roots[i]);
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c index 94f8c34fc293..b3f0dd652088 100644 --- a/drivers/gpu/drm/drm_buddy.c +++ b/drivers/gpu/drm/drm_buddy.c @@ -324,7 +324,7 @@ EXPORT_SYMBOL(drm_buddy_init); */ void drm_buddy_fini(struct drm_buddy *mm) { - u64 root_size, size; + u64 root_size, size, start; unsigned int order; int i; @@ -332,7 +332,8 @@ void drm_buddy_fini(struct drm_buddy *mm) for (i = 0; i < mm->n_roots; ++i) { order = ilog2(size) - ilog2(mm->chunk_size); - __force_merge(mm, 0, size, order); + start = drm_buddy_block_offset(mm->roots[i]); + __force_merge(mm, start, start + size, order); WARN_ON(!drm_buddy_block_is_free(mm->roots[i])); drm_block_free(mm, mm->roots[i]);
If buddy manager have more than one roots and each root have sub-block need to be free. When drm_buddy_fini called, the first loop of force_merge will merge and free all of the sub block of first root, which offset is 0x0 and size is biggest(more than have of the mm size). In subsequent force_merge rounds, if we use 0 as start and use remaining mm size as end, the block of other roots will be skipped in __force_merge function. It will cause the other roots can not be freed. Solution: use roots' offset as the start could fix this issue. Signed-off-by: Lin.Cao <lincao12@amd.com> --- drivers/gpu/drm/drm_buddy.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)