[PATCH 04/10] mm/hugetlb: count file_region to be added when regions_needed != NULL

Wei Yang
2020-08-07T09:13:39Z

There are only two cases of function add_reservation_in_range()

* count file_region and return the number in regions_needed
* do the real list operation without counting

This means it is not necessary to have two parameters to classify these
two cases.

Just use regions_needed to separate them.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
---
mm/hugetlb.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 929256c130f9..d775e514eb2e 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -321,16 +321,17 @@ static void coalesce_file_region(struct resv_map *resv, struct file_region *rg)
}
}

-/* Must be called with resv->lock held. Calling this with count_only == true
- * will count the number of pages to be added but will not modify the linked
- * list. If regions_needed != NULL and count_only == true, then regions_needed
- * will indicate the number of file_regions needed in the cache to carry out to
- * add the regions for this range.
+/*
+ * Must be called with resv->lock held.
+ *
+ * Calling this with regions_needed != NULL will count the number of pages
+ * to be added but will not modify the linked list. And regions_needed will
+ * indicate the number of file_regions needed in the cache to carry out to add
+ * the regions for this range.
*/
static long add_reservation_in_range(struct resv_map *resv, long f, long t,
struct hugetlb_cgroup *h_cg,
- struct hstate *h, long *regions_needed,
- bool count_only)
+ struct hstate *h, long *regions_needed)
{
long add = 0;
struct list_head *head = &resv->regions;
@@ -366,14 +367,14 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t,
*/
if (rg->from > last_accounted_offset) {
add += rg->from - last_accounted_offset;
- if (!count_only) {
+ 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 if (regions_needed)
+ } else
*regions_needed += 1;
}

@@ -385,13 +386,13 @@ static long add_reservation_in_range(struct resv_map *resv, long f, long t,
*/
if (last_accounted_offset < t) {
add += t - last_accounted_offset;
- if (!count_only) {
+ 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 if (regions_needed)
+ } else
*regions_needed += 1;
}

@@ -484,8 +485,8 @@ static long region_add(struct resv_map *resv, long f, long t,
retry:

/* Count how many regions are actually needed to execute this add. */
- add_reservation_in_range(resv, f, t, NULL, NULL, &actual_regions_needed,
- true);
+ add_reservation_in_range(resv, f, t, NULL, NULL,
+ &actual_regions_needed);

/*
* Check for sufficient descriptors in the cache to accommodate
@@ -513,7 +514,7 @@ static long region_add(struct resv_map *resv, long f, long t,
goto retry;
}

- add = add_reservation_in_range(resv, f, t, h_cg, h, NULL, false);
+ add = add_reservation_in_range(resv, f, t, h_cg, h, NULL);

resv->adds_in_progress -= in_regions_needed;

@@ -549,9 +550,9 @@ static long region_chg(struct resv_map *resv, long f, long t,

spin_lock(&resv->lock);

- /* Count how many hugepages in this range are NOT respresented. */
+ /* Count how many hugepages in this range are NOT represented. */
chg = add_reservation_in_range(resv, f, t, NULL, NULL,
- out_regions_needed, true);
+ out_regions_needed);

if (*out_regions_needed == 0)
*out_regions_needed = 1;
--
2.20.1 (Apple Git-117)