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Subject[PATCH] memblock: remove repeat round
Date
There is no need round twice in memblock_add_range().

We can call memblock_double_array() to extand the size if type->cnt no
less than type->max before memblock_insert_region(), otherwise we can
insert the new region directly.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
---
mm/memblock.c | 54 +++++++++++++++------------------------------------
1 file changed, 16 insertions(+), 38 deletions(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 511d4783dcf1..1679244b4a1a 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -578,7 +578,6 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
phys_addr_t base, phys_addr_t size,
int nid, enum memblock_flags flags)
{
- bool insert = false;
phys_addr_t obase = base;
phys_addr_t end = base + memblock_cap_size(base, &size);
int idx, nr_new;
@@ -598,22 +597,6 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
return 0;
}

- /*
- * The worst case is when new range overlaps all existing regions,
- * then we'll need type->cnt + 1 empty regions in @type. So if
- * type->cnt * 2 + 1 is less than type->max, we know
- * that there is enough empty regions in @type, and we can insert
- * regions directly.
- */
- if (type->cnt * 2 + 1 < type->max)
- insert = true;
-
-repeat:
- /*
- * The following is executed twice. Once with %false @insert and
- * then with %true. The first counts the number of regions needed
- * to accommodate the new area. The second actually inserts them.
- */
base = obase;
nr_new = 0;

@@ -635,10 +618,14 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
#endif
WARN_ON(flags != rgn->flags);
nr_new++;
- if (insert)
- memblock_insert_region(type, idx++, base,
- rbase - base, nid,
- flags);
+
+ if ((type->cnt >= type->max) &&
+ (memblock_double_array(type, obase, size) < 0))
+ return -ENOMEM;
+
+ memblock_insert_region(type, idx++, base,
+ rbase - base, nid,
+ flags);
}
/* area below @rend is dealt with, forget about it */
base = min(rend, end);
@@ -647,28 +634,19 @@ static int __init_memblock memblock_add_range(struct memblock_type *type,
/* insert the remaining portion */
if (base < end) {
nr_new++;
- if (insert)
- memblock_insert_region(type, idx, base, end - base,
- nid, flags);
+ if ((type->cnt >= type->max) &&
+ (memblock_double_array(type, obase, size) < 0))
+ return -ENOMEM;
+
+ memblock_insert_region(type, idx, base, end - base,
+ nid, flags);
}

if (!nr_new)
return 0;

- /*
- * If this was the first round, resize array and repeat for actual
- * insertions; otherwise, merge and return.
- */
- if (!insert) {
- while (type->cnt + nr_new > type->max)
- if (memblock_double_array(type, obase, size) < 0)
- return -ENOMEM;
- insert = true;
- goto repeat;
- } else {
- memblock_merge_regions(type);
- return 0;
- }
+ memblock_merge_regions(type);
+ return 0;
}

/**
--
2.25.1
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