[PATCH v2 2/4] hugetlg: Break earlier in add_reservation_in_range() when we can

Peter Xu
2021-02-04T14:53:44Z

All the regions maintained in hugetlb reserved map is inclusive on "from" but
exclusive on "to". We can break earlier even if rg->from==t because it already
means no possible intersection.

This does not need a Fixes in all cases because when it happens (rg->from==t)
we'll not break out of the loop while we should, however the next thing we'd do
is still add the last file_region we'd need and quit the loop in the next
round. So this change is not a bugfix (since the old code should still run
okay iiuc), but we'd better still touch it up to make it logically sane.

Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
---
mm/hugetlb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d2859c2aecc9..9e6ea96bf33b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -377,7 +377,7 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t,
/* When we find a region that starts beyond our range, we've
* finished.
*/
- if (rg->from > t)
+ if (rg->from >= t)
break;

/* Add an entry for last_accounted_offset -> rg->from, and
--
2.26.2