Messages in this thread | | | Subject | Re: [PATCH v5 1/5] mm: introduce debug_pagealloc_{map,unmap}_pages() helpers | From | Vlastimil Babka <> | Date | Mon, 9 Nov 2020 12:33:46 +0100 |
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On 11/8/20 7:57 AM, Mike Rapoport wrote: > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -1428,21 +1428,19 @@ static bool is_debug_pagealloc_cache(struct kmem_cache *cachep) > return false; > } > > -#ifdef CONFIG_DEBUG_PAGEALLOC > static void slab_kernel_map(struct kmem_cache *cachep, void *objp, int map) > { > if (!is_debug_pagealloc_cache(cachep)) > return;
Hmm, I didn't notice earlier, sorry. The is_debug_pagealloc_cache() above includes a debug_pagealloc_enabled_static() check, so it should be fine to use __kernel_map_pages() directly below. Otherwise we generate two static key checks for the same key needlessly.
> > - kernel_map_pages(virt_to_page(objp), cachep->size / PAGE_SIZE, map); > + if (map) > + debug_pagealloc_map_pages(virt_to_page(objp), > + cachep->size / PAGE_SIZE); > + else > + debug_pagealloc_unmap_pages(virt_to_page(objp), > + cachep->size / PAGE_SIZE); > } > > -#else > -static inline void slab_kernel_map(struct kmem_cache *cachep, void *objp, > - int map) {} > - > -#endif > - > static void poison_obj(struct kmem_cache *cachep, void *addr, unsigned char val) > { > int size = cachep->object_size; > @@ -2062,7 +2060,7 @@ int __kmem_cache_create(struct kmem_cache *cachep, slab_flags_t flags) > > #if DEBUG > /* > - * If we're going to use the generic kernel_map_pages() > + * If we're going to use the generic debug_pagealloc_map_pages() > * poisoning, then it's going to smash the contents of > * the redzone and userword anyhow, so switch them off. > */ >
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