[PATCH 2/3] percpu: merge two loops when setting up group info

[Wei Yang]

There are two loops setting up the group info of pcpu_alloc_info. They share
the same logic, so merge them could be time efficient when there are many
groups.

This patch merge these two loops into one.

Signed-off-by: Wei Yang <weiyang@xxxxxxxxxxxxxxxxxx>
---
 mm/percpu.c |    8 +++-----
 1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/mm/percpu.c b/mm/percpu.c
index 536ca4f..4f710a4f 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1542,11 +1542,6 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info(
 		return ERR_PTR(-ENOMEM);
 	cpu_map = ai->groups[0].cpu_map;
 
-	for (group = 0; group < nr_groups; group++) {
-		ai->groups[group].cpu_map = cpu_map;
-		cpu_map += roundup(group_cnt[group], upa);
-	}
-
 	ai->static_size = static_size;
 	ai->reserved_size = reserved_size;
 	ai->dyn_size = dyn_size;
@@ -1557,6 +1552,8 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info(
 	for (group = 0, unit = 0; group_cnt[group]; group++) {
 		struct pcpu_group_info *gi = &ai->groups[group];
 
+		gi->cpu_map = cpu_map;
+
 		/*
 		 * Initialize base_offset as if all groups are located
 		 * back-to-back.  The caller should update this to
@@ -1568,6 +1565,7 @@ static struct pcpu_alloc_info * __init pcpu_build_alloc_info(
 			if (group_map[cpu] == group)
 				gi->cpu_map[gi->nr_units++] = cpu;
 		gi->nr_units = roundup(gi->nr_units, upa);
+		cpu_map += gi->nr_units;
 		unit += gi->nr_units;
 	}
 	BUG_ON(unit != nr_units);
-- 
1.7.5.4

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