From: Vlastimil Babka <vbabka@xxxxxxx> Subject: mm, sl[ou]b: improve memory accounting Patch series "guarantee natural alignment for kmalloc()", v2. This patch (of 2): SLOB currently doesn't account its pages at all, so in /proc/meminfo the Slab field shows zero. Modifying a counter on page allocation and freeing should be acceptable even for the small system scenarios SLOB is intended for. Since reclaimable caches are not separated in SLOB, account everything as unreclaimable. SLUB currently doesn't account kmalloc() and kmalloc_node() allocations larger than order-1 page, that are passed directly to the page allocator. As they also don't appear in /proc/slabinfo, it might look like a memory leak. For consistency, account them as well. (SLAB doesn't actually use page allocator directly, so no change there). Ideally SLOB and SLUB would be handled in separate patches, but due to the shared kmalloc_order() function and different kfree() implementations, it's easier to patch both at once to prevent inconsistencies. Link: http://lkml.kernel.org/r/20190826111627.7505-2-vbabka@xxxxxxx Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Ming Lei <ming.lei@xxxxxxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: "Darrick J . Wong" <darrick.wong@xxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slab_common.c | 8 ++++++-- mm/slob.c | 20 ++++++++++++++++---- mm/slub.c | 14 +++++++++++--- 3 files changed, 33 insertions(+), 9 deletions(-) --- a/mm/slab_common.c~mm-slb-improve-memory-accounting +++ a/mm/slab_common.c @@ -1287,12 +1287,16 @@ void __init create_kmalloc_caches(slab_f */ void *kmalloc_order(size_t size, gfp_t flags, unsigned int order) { - void *ret; + void *ret = NULL; struct page *page; flags |= __GFP_COMP; page = alloc_pages(flags, order); - ret = page ? page_address(page) : NULL; + if (likely(page)) { + ret = page_address(page); + mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE, + 1 << order); + } ret = kasan_kmalloc_large(ret, size, flags); /* As ret might get tagged, call kmemleak hook after KASAN. */ kmemleak_alloc(ret, size, 1, flags); --- a/mm/slob.c~mm-slb-improve-memory-accounting +++ a/mm/slob.c @@ -190,7 +190,7 @@ static int slob_last(slob_t *s) static void *slob_new_pages(gfp_t gfp, int order, int node) { - void *page; + struct page *page; #ifdef CONFIG_NUMA if (node != NUMA_NO_NODE) @@ -202,14 +202,21 @@ static void *slob_new_pages(gfp_t gfp, i if (!page) return NULL; + mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE, + 1 << order); return page_address(page); } static void slob_free_pages(void *b, int order) { + struct page *sp = virt_to_page(b); + if (current->reclaim_state) current->reclaim_state->reclaimed_slab += 1 << order; - free_pages((unsigned long)b, order); + + mod_node_page_state(page_pgdat(sp), NR_SLAB_UNRECLAIMABLE, + -(1 << order)); + __free_pages(sp, order); } /* @@ -521,8 +528,13 @@ void kfree(const void *block) 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 - __free_pages(sp, compound_order(sp)); + } else { + unsigned int order = compound_order(sp); + mod_node_page_state(page_pgdat(sp), NR_SLAB_UNRECLAIMABLE, + -(1 << order)); + __free_pages(sp, order); + + } } EXPORT_SYMBOL(kfree); --- a/mm/slub.c~mm-slb-improve-memory-accounting +++ a/mm/slub.c @@ -3821,11 +3821,15 @@ static void *kmalloc_large_node(size_t s { struct page *page; void *ptr = NULL; + unsigned int order = get_order(size); flags |= __GFP_COMP; - page = alloc_pages_node(node, flags, get_order(size)); - if (page) + page = alloc_pages_node(node, flags, order); + if (page) { ptr = page_address(page); + mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE, + 1 << order); + } return kmalloc_large_node_hook(ptr, size, flags); } @@ -3951,9 +3955,13 @@ void kfree(const void *x) page = virt_to_head_page(x); if (unlikely(!PageSlab(page))) { + unsigned int order = compound_order(page); + BUG_ON(!PageCompound(page)); kfree_hook(object); - __free_pages(page, compound_order(page)); + mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE, + -(1 << order)); + __free_pages(page, order); return; } slab_free(page->slab_cache, page, object, NULL, 1, _RET_IP_); _
