hugetlbfs: accept subpool min_size mount option and setup accordingly
Make 'min_size=<value>' be an option when mounting a hugetlbfs. This
option takes the same value as the 'size' option. min_size can be
specified without specifying size. If both are specified, min_size must
be less that or equal to size else the mount will fail. If min_size is
specified, then at mount time an attempt is made to reserve min_size
pages. If the reservation fails, the mount fails. At umount time, the
reserved pages are released.
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 499cb72..995c8d6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -61,6 +61,9 @@
static int num_fault_mutexes;
static struct mutex *htlb_fault_mutex_table ____cacheline_aligned_in_smp;
+/* Forward declaration */
+static int hugetlb_acct_memory(struct hstate *h, long delta);
+
static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
{
bool free = (spool->count == 0) && (spool->used_hpages == 0);
@@ -68,12 +71,18 @@
spin_unlock(&spool->lock);
/* If no pages are used, and no other handles to the subpool
- * remain, free the subpool the subpool remain */
- if (free)
+ * remain, give up any reservations mased on minimum size and
+ * free the subpool */
+ if (free) {
+ if (spool->min_hpages != -1)
+ hugetlb_acct_memory(spool->hstate,
+ -spool->min_hpages);
kfree(spool);
+ }
}
-struct hugepage_subpool *hugepage_new_subpool(long nr_blocks)
+struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
+ long min_hpages)
{
struct hugepage_subpool *spool;
@@ -83,7 +92,15 @@
spin_lock_init(&spool->lock);
spool->count = 1;
- spool->max_hpages = nr_blocks;
+ spool->max_hpages = max_hpages;
+ spool->hstate = h;
+ spool->min_hpages = min_hpages;
+
+ if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) {
+ kfree(spool);
+ return NULL;
+ }
+ spool->rsv_hpages = min_hpages;
return spool;
}