On Wed, 2024-02-21 at 11:26 +0100, Christian König wrote: > Am 21.02.24 um 08:33 schrieb Thomas Hellström: > > If caching mode change fails due to, for example, OOM we > > free the allocated pages in a two-step process. First the pages > > for which the caching change has already succeeded. Secondly > > the pages for which a caching change did not succeed. > > > > However the second step was incorrectly freeing the pages already > > freed in the first step. > > > > Fix. > > > > Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx> > > Fixes: 379989e7cbdc ("drm/ttm/pool: Fix ttm_pool_alloc error path") > > Cc: Christian König <christian.koenig@xxxxxxx> > > Cc: Dave Airlie <airlied@xxxxxxxxxx> > > Cc: Christian Koenig <christian.koenig@xxxxxxx> > > Cc: Huang Rui <ray.huang@xxxxxxx> > > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx > > Cc: <stable@xxxxxxxxxxxxxxx> # v6.4+ > > You don't know how much time I've spend staring at this line to find > the > bug in it and haven't seen it. Got bug reports about that for month > as well. Yeah, sorry about that. We should probably have Kunit tests exercising OOM in the pool code involving WC pages. I'll push this to drm-misc-next. /Thomas > > Reviewed-by: Christian König <christian.koenig@xxxxxxx> > > > --- > > drivers/gpu/drm/ttm/ttm_pool.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/ttm/ttm_pool.c > > b/drivers/gpu/drm/ttm/ttm_pool.c > > index b62f420a9f96..112438d965ff 100644 > > --- a/drivers/gpu/drm/ttm/ttm_pool.c > > +++ b/drivers/gpu/drm/ttm/ttm_pool.c > > @@ -387,7 +387,7 @@ static void ttm_pool_free_range(struct ttm_pool > > *pool, struct ttm_tt *tt, > > enum ttm_caching caching, > > pgoff_t start_page, pgoff_t > > end_page) > > { > > - struct page **pages = tt->pages; > > + struct page **pages = &tt->pages[start_page]; > > unsigned int order; > > pgoff_t i, nr; > > >