On Wed, 21 Apr 2021, Matthew Wilcox wrote: > On Wed, Apr 21, 2021 at 10:25:17AM +0800, Yejune Deng wrote: > > @@ -3045,12 +3044,7 @@ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) > > } > > > > STATS_INC_ALLOCMISS(cachep); > > - objp = cache_alloc_refill(cachep, flags); > > - /* > > - * the 'ac' may be updated by cache_alloc_refill(), > > - * and kmemleak_erase() requires its correct value. > > - */ > > - ac = cpu_cache_get(cachep); > > + objp = cache_alloc_refill(cachep, ac, flags); > > I think passing 'ac' in is fine (probably? I don't know this code > deeply), but deleting this call to 'ac' is clearly wrong. The comment > even tells you that! I just verified the code, and the comment is > correct. Yep the delete of the ac assignment is wrong. But even without that issue: There is no point to passing ac to cache_alloc_refill since cpu_cache_get is rather trivial and does not even require memory access since "cachep" is usually in some register.
