From 6a486c0ad4dcdee3946842c64884d2978bfe2602 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Sun, 6 Oct 2019 17:58:42 -0700 Subject: [PATCH] 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@suse.cz Signed-off-by: Vlastimil Babka Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Ming Lei Cc: Dave Chinner Cc: Matthew Wilcox Cc: "Darrick J . Wong" Cc: Christoph Hellwig Cc: James Bottomley Cc: Vlastimil Babka Cc: Joonsoo Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab_common.c | 8 ++++++-- mm/slob.c | 20 ++++++++++++++++---- mm/slub.c | 14 +++++++++++--- 3 files changed, 33 insertions(+), 9 deletions(-) diff --git a/mm/slab_common.c b/mm/slab_common.c index 6491c3a41805..0a94cf858aa4 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -1287,12 +1287,16 @@ void __init create_kmalloc_caches(slab_flags_t flags) */ 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); diff --git a/mm/slob.c b/mm/slob.c index cf377beab962..835088d55645 100644 --- a/mm/slob.c +++ b/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, int order, int node) 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); diff --git a/mm/slub.c b/mm/slub.c index 42c1b3af3c98..3d63ae320d31 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3821,11 +3821,15 @@ static void *kmalloc_large_node(size_t size, gfp_t flags, int node) { 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_);