From: Wei Yang <richard.weiyang@gmail.com>
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 <richard.weiyang@gmail.com>
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 [thread overview]
Message-ID: <20180823130732.9489-2-richard.weiyang@gmail.com> (raw)
In-Reply-To: <20180823130732.9489-1-richard.weiyang@gmail.com>
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 <richard.weiyang@gmail.com>
---
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
next prev parent reply other threads:[~2018-08-23 13:08 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-23 13:07 [PATCH 0/3] trivial code refine for sparsemem Wei Yang
2018-08-23 13:07 ` Wei Yang [this message]
2018-08-23 13:13 ` [PATCH 1/3] mm/sparse: add likely to mem_section[root] check in sparse_index_init() Michal Hocko
2018-08-23 22:57 ` Wei Yang
2018-08-24 7:31 ` Michal Hocko
2018-08-24 0:11 ` Dave Hansen
2018-08-24 15:07 ` Wei Yang
2018-09-03 22:27 ` Wei Yang
2018-09-09 1:38 ` Wei Yang
2018-09-10 20:30 ` Dave Hansen
2018-09-11 15:00 ` Wei Yang
2018-08-23 13:07 ` [PATCH 2/3] mm/sparse: expand the CONFIG_SPARSEMEM_EXTREME range in __nr_to_section() Wei Yang
2018-08-23 13:21 ` Michal Hocko
2018-08-23 23:03 ` Wei Yang
2018-08-24 0:09 ` Dave Hansen
2018-08-24 15:24 ` Wei Yang
2018-08-23 13:07 ` [PATCH 3/3] mm/sparse: use __highest_present_section_nr as the boundary for pfn check Wei Yang
2018-08-23 13:25 ` Michal Hocko
2018-08-23 14:00 ` Oscar Salvador
2018-08-23 19:17 ` Michal Hocko
2018-08-23 20:52 ` Oscar Salvador
2018-08-24 0:15 ` Dave Hansen
2018-08-24 18:11 ` Wei Yang
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