From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f69.google.com (mail-pl0-f69.google.com [209.85.160.69]) by kanga.kvack.org (Postfix) with ESMTP id 7BCF46B0005 for ; Tue, 19 Jun 2018 17:34:01 -0400 (EDT) Received: by mail-pl0-f69.google.com with SMTP id t17-v6so502491ply.13 for ; Tue, 19 Jun 2018 14:34:01 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id v41-v6sor236721plg.73.2018.06.19.14.34.00 for (Google Transport Security); Tue, 19 Jun 2018 14:34:00 -0700 (PDT) From: Shakeel Butt Subject: [PATCH] slub: fix __kmem_cache_empty for !CONFIG_SLUB_DEBUG Date: Tue, 19 Jun 2018 14:33:52 -0700 Message-Id: <20180619213352.71740-1-shakeelb@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Jason A . Donenfeld" Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Shakeel Butt , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , stable@vger.kernel.org For !CONFIG_SLUB_DEBUG, SLUB does not maintain the number of slabs allocated per node for a kmem_cache. Thus, slabs_node() in __kmem_cache_empty() will always return 0. So, in such situation, it is required to check per-cpu slabs to make sure if a kmem_cache is empty or not. Please note that __kmem_cache_shutdown() and __kmem_cache_shrink() are not affected by !CONFIG_SLUB_DEBUG as they call flush_all() to clear per-cpu slabs. Fixes: f9e13c0a5a33 ("slab, slub: skip unnecessary kasan_cache_shutdown()") Signed-off-by: Shakeel Butt Reported-by: Jason A . Donenfeld Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Andrew Morton Cc: --- mm/slub.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index a3b8467c14af..731c02b371ae 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3673,9 +3673,23 @@ static void free_partial(struct kmem_cache *s, struct kmem_cache_node *n) bool __kmem_cache_empty(struct kmem_cache *s) { - int node; + int cpu, node; struct kmem_cache_node *n; + /* + * slabs_node will always be 0 for !CONFIG_SLUB_DEBUG. So, manually + * check slabs for all cpus. + */ + if (!IS_ENABLED(CONFIG_SLUB_DEBUG)) { + for_each_online_cpu(cpu) { + struct kmem_cache_cpu *c; + + c = per_cpu_ptr(s->cpu_slab, cpu); + if (c->page || slub_percpu_partial(c)) + return false; + } + } + for_each_kmem_cache_node(s, node, n) if (n->nr_partial || slabs_node(s, node)) return false; -- 2.18.0.rc1.244.gcf134e6275-goog