On Wed, Jun 10, 2020 at 06:31:33PM +0200, Vlastimil Babka wrote: > There are few places that call kmem_cache_debug(s) (which tests if any of > debug > flags are enabled for a cache) immediatelly followed by a test for a specific > flag. The compiler can probably eliminate the extra check, but we can make the > code nicer by introducing kmem_cache_debug_flags() that works like > kmem_cache_debug() (including the static key check) but tests for specifig > flag(s). The next patches will add more users. > > Signed-off-by: Vlastimil Babka <[email protected]> > --- > mm/slub.c | 18 ++++++++++++++---- > 1 file changed, 14 insertions(+), 4 deletions(-)
Acked-by: Roman Gushchin <[email protected]> One small nit below. > > diff --git a/mm/slub.c b/mm/slub.c > index 24d3e5f832aa..c8e8b4ae2451 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -122,18 +122,28 @@ DEFINE_STATIC_KEY_FALSE(slub_debug_enabled); > #endif > #endif > > -static inline int kmem_cache_debug(struct kmem_cache *s) > +/* > + * Returns true if any of the specified slub_debug flags is enabled for the > + * cache. Use only for flags parsed by setup_slub_debug() as it also enables > + * the static key. Maybe adding VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS)) to make sure the flags argument is valid? > + */ > +static inline int kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t > flags) > { > #ifdef CONFIG_SLUB_DEBUG > if (static_branch_unlikely(&slub_debug_enabled)) > - return s->flags & SLAB_DEBUG_FLAGS; > + return s->flags & flags; > #endif > return 0; > } > > +static inline int kmem_cache_debug(struct kmem_cache *s) > +{ > + return kmem_cache_debug_flags(s, SLAB_DEBUG_FLAGS); > +} > + > void *fixup_red_left(struct kmem_cache *s, void *p) > { > - if (kmem_cache_debug(s) && s->flags & SLAB_RED_ZONE) > + if (kmem_cache_debug_flags(s, SLAB_RED_ZONE)) > p += s->red_left_pad; > > return p; > @@ -4076,7 +4086,7 @@ void __check_heap_object(const void *ptr, unsigned long > n, struct page *page, > offset = (ptr - page_address(page)) % s->size; > > /* Adjust for redzone and reject if within the redzone. */ > - if (kmem_cache_debug(s) && s->flags & SLAB_RED_ZONE) { > + if (kmem_cache_debug_flags(s, SLAB_RED_ZONE)) { > if (offset < s->red_left_pad) > usercopy_abort("SLUB object in left red zone", > s->name, to_user, offset, n); > -- > 2.26.2 >
