free_pcppages_bulk() frees pages in a round-robin fashion. Originally,
this was dealing only with migratetypes but storing high-order pages
means that there can be many more empty lists that are uselessly
checked. Track the minimum and maximum active pindex to reduce the
search space.
Signed-off-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 08de32cfd9bb..c5110fdeb115 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1450,6 +1450,8 @@ static void free_pcppages_bulk(struct zone *zone, int count,
struct per_cpu_pages *pcp)
{
int pindex = 0;
+ int min_pindex = 0;
+ int max_pindex = NR_PCP_LISTS - 1;
int batch_free = 0;
int nr_freed = 0;
unsigned int order;
@@ -1478,10 +1480,17 @@ static void free_pcppages_bulk(struct zone *zone, int count,
if (++pindex == NR_PCP_LISTS)
pindex = 0;
list = &pcp->lists[pindex];
- } while (list_empty(list));
+ if (!list_empty(list))
+ break;
+
+ if (pindex == max_pindex)
+ max_pindex--;
+ if (pindex == min_pindex)
+ min_pindex++;
+ } while (1);
/* This is the only non-empty list. Free them all. */
- if (batch_free == NR_PCP_LISTS)
+ if (batch_free >= max_pindex - min_pindex)
batch_free = count;
order = pindex_to_order(pindex);
--
2.31.1
