[PATCH 1/2] mm/percpu.c: renew the max_contig if we merge the head and previous block

From: Jianyu Zhan
Date: Fri Mar 28 2014 - 08:55:48 EST


Hi, tj,
I've reworked the patches on top of percpu/for-3.15.

During pcpu_alloc_area(), we might merge the current head with the
previous block. Since we have calculated the max_contig using the
size of previous block before we skip it, and now we update the size
of previous block, so we should renew the max_contig.

Signed-off-by: Jianyu Zhan <nasa4836@xxxxxxxxx>
---
mm/percpu.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/percpu.c b/mm/percpu.c
index 202e104..63e24fb 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -473,9 +473,11 @@ static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align)
* uncommon for percpu allocations.
*/
if (head && (head < sizeof(int) || !(p[-1] & 1))) {
+ *p = off += head;
if (p[-1] & 1)
chunk->free_size -= head;
- *p = off += head;
+ else
+ max_contig = max(*p - p[-1], max_contig);
this_size -= head;
head = 0;
}
--
1.8.5.3

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