[PATCH 1/4] hugetlb: Dedup the code to add a new file_region

Peter Xu
2021-02-03T21:10:19Z

Introduce hugetlb_resv_map_add() helper to add a new file_region rather than
duplication the similar code twice in add_reservation_in_range().

Signed-off-by: Peter Xu <peterx@redhat.com>
---
mm/hugetlb.c | 51 +++++++++++++++++++++++++++------------------------
1 file changed, 27 insertions(+), 24 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 18f6ee317900..d2859c2aecc9 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -321,6 +321,24 @@ static void coalesce_file_region(struct resv_map *resv, struct file_region *rg)
}
}

+static inline long
+hugetlb_resv_map_add(struct resv_map *map, struct file_region *rg, long from,
+ long to, struct hstate *h, struct hugetlb_cgroup *cg,
+ long *regions_needed)
+{
+ struct file_region *nrg;
+
+ if (!regions_needed) {
+ nrg = get_file_region_entry_from_cache(map, from, to);
+ record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg);
+ list_add(&nrg->link, rg->link.prev);
+ coalesce_file_region(map, nrg);
+ } else
+ *regions_needed += 1;
+
+ return to - from;
+}
+
/*
* Must be called with resv->lock held.
*
@@ -336,7 +354,7 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t,
long add = 0;
struct list_head *head = &resv->regions;
long last_accounted_offset = f;
- struct file_region *rg = NULL, *trg = NULL, *nrg = NULL;
+ struct file_region *rg = NULL, *trg = NULL;

if (regions_needed)
*regions_needed = 0;
@@ -365,18 +383,11 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t,
/* Add an entry for last_accounted_offset -> rg->from, and
* update last_accounted_offset.
*/
- if (rg->from > last_accounted_offset) {
- add += rg->from - last_accounted_offset;
- if (!regions_needed) {
- nrg = get_file_region_entry_from_cache(
- resv, last_accounted_offset, rg->from);
- record_hugetlb_cgroup_uncharge_info(h_cg, h,
- resv, nrg);
- list_add(&nrg->link, rg->link.prev);
- coalesce_file_region(resv, nrg);
- } else
- *regions_needed += 1;
- }
+ if (rg->from > last_accounted_offset)
+ add += hugetlb_resv_map_add(resv, rg,
+ last_accounted_offset,
+ rg->from, h, h_cg,
+ regions_needed);

last_accounted_offset = rg->to;
}
@@ -384,17 +395,9 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t,
/* Handle the case where our range extends beyond
* last_accounted_offset.
*/
- if (last_accounted_offset < t) {
- add += t - last_accounted_offset;
- if (!regions_needed) {
- nrg = get_file_region_entry_from_cache(
- resv, last_accounted_offset, t);
- record_hugetlb_cgroup_uncharge_info(h_cg, h, resv, nrg);
- list_add(&nrg->link, rg->link.prev);
- coalesce_file_region(resv, nrg);
- } else
- *regions_needed += 1;
- }
+ if (last_accounted_offset < t)
+ add += hugetlb_resv_map_add(resv, rg, last_accounted_offset,
+ t, h, h_cg, regions_needed);

VM_BUG_ON(add < 0);
return add;
--
2.26.2