From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id 6C3136B2A31 for ; Thu, 23 Aug 2018 09:08:06 -0400 (EDT) Received: by mail-pf1-f198.google.com with SMTP id d22-v6so3198543pfn.3 for ; Thu, 23 Aug 2018 06:08:06 -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 g12-v6sor250853pgr.8.2018.08.23.06.08.05 for (Google Transport Security); Thu, 23 Aug 2018 06:08:05 -0700 (PDT) From: Wei Yang Subject: [PATCH 1/3] mm/sparse: add likely to mem_section[root] check in sparse_index_init() Date: Thu, 23 Aug 2018 21:07:30 +0800 Message-Id: <20180823130732.9489-2-richard.weiyang@gmail.com> In-Reply-To: <20180823130732.9489-1-richard.weiyang@gmail.com> References: <20180823130732.9489-1-richard.weiyang@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org, mhocko@suse.com, rientjes@google.com Cc: linux-mm@kvack.org, kirill.shutemov@linux.intel.com, bob.picco@hp.com, Wei Yang Each time SECTIONS_PER_ROOT number of mem_section is allocated when mem_section[root] is null. This means only (1 / SECTIONS_PER_ROOT) chance of the mem_section[root] check is false. This patch adds likely to the if check to optimize this a little. Signed-off-by: Wei Yang --- mm/sparse.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/sparse.c b/mm/sparse.c index 10b07eea9a6e..90bab7f03757 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -78,7 +78,7 @@ static int __meminit sparse_index_init(unsigned long section_nr, int nid) unsigned long root = SECTION_NR_TO_ROOT(section_nr); struct mem_section *section; - if (mem_section[root]) + if (likely(mem_section[root])) return -EEXIST; section = sparse_index_alloc(nid); -- 2.15.1