From 75c8ff281d7a6faa650bb9b32052f3ee1b5f8e83 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Tue, 11 May 2021 14:05:22 +0200 Subject: [PATCH] mm, slub: return slab page from get_partial() and set c->page afterwards The function get_partial() finds a suitable page on a partial list, acquires and returns its freelist and assigns the page pointer to kmem_cache_cpu. In later patch we will need more control over the kmem_cache_cpu.page assignment, so instead of passing a kmem_cache_cpu pointer, pass a pointer to a pointer to a page that get_partial() can fill and the caller can assign the kmem_cache_cpu.page pointer. No functional change as all of this still happens with disabled IRQs. Signed-off-by: Vlastimil Babka --- mm/slub.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 0c645b0..e9d582ee 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2017,7 +2017,7 @@ static inline bool pfmemalloc_match(struct page *page, gfp_t gfpflags); * Try to allocate a partial slab from a specific node. */ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, - struct kmem_cache_cpu *c, gfp_t flags) + struct page **ret_page, gfp_t flags) { struct page *page, *page2; void *object = NULL; @@ -2046,7 +2046,7 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, available += objects; if (!object) { - c->page = page; + *ret_page = page; stat(s, ALLOC_FROM_PARTIAL); object = t; } else { @@ -2066,7 +2066,7 @@ static void *get_partial_node(struct kmem_cache *s, struct kmem_cache_node *n, * Get a page from somewhere. Search in increasing NUMA distances. */ static void *get_any_partial(struct kmem_cache *s, gfp_t flags, - struct kmem_cache_cpu *c) + struct page **ret_page) { #ifdef CONFIG_NUMA struct zonelist *zonelist; @@ -2108,7 +2108,7 @@ static void *get_any_partial(struct kmem_cache *s, gfp_t flags, if (n && cpuset_zone_allowed(zone, flags) && n->nr_partial > s->min_partial) { - object = get_partial_node(s, n, c, flags); + object = get_partial_node(s, n, ret_page, flags); if (object) { /* * Don't check read_mems_allowed_retry() @@ -2130,7 +2130,7 @@ static void *get_any_partial(struct kmem_cache *s, gfp_t flags, * Get a partial page, lock it and return it. */ static void *get_partial(struct kmem_cache *s, gfp_t flags, int node, - struct kmem_cache_cpu *c) + struct page **ret_page) { void *object; int searchnode = node; @@ -2138,11 +2138,11 @@ static void *get_partial(struct kmem_cache *s, gfp_t flags, int node, if (node == NUMA_NO_NODE) searchnode = numa_mem_id(); - object = get_partial_node(s, get_node(s, searchnode), c, flags); + object = get_partial_node(s, get_node(s, searchnode), ret_page, flags); if (object || node != NUMA_NO_NODE) return object; - return get_any_partial(s, flags, c); + return get_any_partial(s, flags, ret_page); } #ifdef CONFIG_PREEMPTION @@ -2754,9 +2754,11 @@ new_slab: goto redo; } - freelist = get_partial(s, gfpflags, node, c); - if (freelist) + freelist = get_partial(s, gfpflags, node, &page); + if (freelist) { + c->page = page; goto check_new_page; + } page = new_slab(s, gfpflags, node); @@ -2780,7 +2782,6 @@ new_slab: c->page = page; check_new_page: - page = c->page; if (likely(!kmem_cache_debug(s) && pfmemalloc_match(page, gfpflags))) goto load_freelist; -- 2.7.4