From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Use struct slab throughout the slob allocator. Where non-slab page can appear use struct folio instead of struct page. [ vbabka@xxxxxxx: don't introduce wrappers for PageSlobFree in mm/slab.h just for the single callers being wrappers in mm/slob.c ] [ Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>: fix NULL pointer deference ] Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx> Tested-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx> --- mm/slob.c | 51 +++++++++++++++++++++++++++------------------------ 1 file changed, 27 insertions(+), 24 deletions(-) diff --git a/mm/slob.c b/mm/slob.c index d2d15e7f191c..3c6cadbbc238 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -30,7 +30,7 @@ * If kmalloc is asked for objects of PAGE_SIZE or larger, it calls * alloc_pages() directly, allocating compound pages so the page order * does not have to be separately tracked. - * These objects are detected in kfree() because PageSlab() + * These objects are detected in kfree() because folio_test_slab() * is false for them. * * SLAB is emulated on top of SLOB by simply calling constructors and @@ -105,21 +105,21 @@ static LIST_HEAD(free_slob_large); /* * slob_page_free: true for pages on free_slob_pages list. */ -static inline int slob_page_free(struct page *sp) +static inline int slob_page_free(struct slab *slab) { - return PageSlobFree(sp); + return PageSlobFree(slab_page(slab)); } -static void set_slob_page_free(struct page *sp, struct list_head *list) +static void set_slob_page_free(struct slab *slab, struct list_head *list) { - list_add(&sp->slab_list, list); - __SetPageSlobFree(sp); + list_add(&slab->slab_list, list); + __SetPageSlobFree(slab_page(slab)); } -static inline void clear_slob_page_free(struct page *sp) +static inline void clear_slob_page_free(struct slab *slab) { - list_del(&sp->slab_list); - __ClearPageSlobFree(sp); + list_del(&slab->slab_list); + __ClearPageSlobFree(slab_page(slab)); } #define SLOB_UNIT sizeof(slob_t) @@ -234,7 +234,7 @@ static void slob_free_pages(void *b, int order) * freelist, in this case @page_removed_from_list will be set to * true (set to false otherwise). */ -static void *slob_page_alloc(struct page *sp, size_t size, int align, +static void *slob_page_alloc(struct slab *sp, size_t size, int align, int align_offset, bool *page_removed_from_list) { slob_t *prev, *cur, *aligned = NULL; @@ -301,7 +301,8 @@ static void *slob_page_alloc(struct page *sp, size_t size, int align, static void *slob_alloc(size_t size, gfp_t gfp, int align, int node, int align_offset) { - struct page *sp; + struct folio *folio; + struct slab *sp; struct list_head *slob_list; slob_t *b = NULL; unsigned long flags; @@ -323,7 +324,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node, * If there's a node specification, search for a partial * page with a matching node id in the freelist. */ - if (node != NUMA_NO_NODE && page_to_nid(sp) != node) + if (node != NUMA_NO_NODE && slab_nid(sp) != node) continue; #endif /* Enough room on this page? */ @@ -358,8 +359,9 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node, b = slob_new_pages(gfp & ~__GFP_ZERO, 0, node); if (!b) return NULL; - sp = virt_to_page(b); - __SetPageSlab(sp); + folio = virt_to_folio(b); + __folio_set_slab(folio); + sp = folio_slab(folio); spin_lock_irqsave(&slob_lock, flags); sp->units = SLOB_UNITS(PAGE_SIZE); @@ -381,7 +383,7 @@ static void *slob_alloc(size_t size, gfp_t gfp, int align, int node, */ static void slob_free(void *block, int size) { - struct page *sp; + struct slab *sp; slob_t *prev, *next, *b = (slob_t *)block; slobidx_t units; unsigned long flags; @@ -391,7 +393,7 @@ static void slob_free(void *block, int size) return; BUG_ON(!size); - sp = virt_to_page(block); + sp = virt_to_slab(block); units = SLOB_UNITS(size); spin_lock_irqsave(&slob_lock, flags); @@ -401,8 +403,8 @@ static void slob_free(void *block, int size) if (slob_page_free(sp)) clear_slob_page_free(sp); spin_unlock_irqrestore(&slob_lock, flags); - __ClearPageSlab(sp); - page_mapcount_reset(sp); + __folio_clear_slab(slab_folio(sp)); + page_mapcount_reset(slab_page(sp)); slob_free_pages(b, 0); return; } @@ -544,7 +546,7 @@ EXPORT_SYMBOL(__kmalloc_node_track_caller); void kfree(const void *block) { - struct page *sp; + struct folio *sp; trace_kfree(_RET_IP_, block); @@ -552,16 +554,17 @@ void kfree(const void *block) return; kmemleak_free(block); - sp = virt_to_page(block); - if (PageSlab(sp)) { + sp = virt_to_folio(block); + if (folio_test_slab(sp)) { int align = max_t(size_t, ARCH_KMALLOC_MINALIGN, ARCH_SLAB_MINALIGN); unsigned int *m = (unsigned int *)(block - align); slob_free(m, *m + align); } else { - unsigned int order = compound_order(sp); - mod_node_page_state(page_pgdat(sp), NR_SLAB_UNRECLAIMABLE_B, + unsigned int order = folio_order(sp); + + mod_node_page_state(folio_pgdat(sp), NR_SLAB_UNRECLAIMABLE_B, -(PAGE_SIZE << order)); - __free_pages(sp, order); + __free_pages(folio_page(sp, 0), order); } } -- 2.34.1