From 7ca02d0ae586fe7df59632966a64f3f1a756ef05 Mon Sep 17 00:00:00 2001 From: Mike Kravetz Date: Wed, 15 Apr 2015 16:13:42 -0700 Subject: hugetlbfs: accept subpool min_size mount option and setup accordingly Make 'min_size=' 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 Cc: Davidlohr Bueso Cc: Aneesh Kumar Cc: Joonsoo Kim Cc: Andi Kleen Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) (limited to 'mm/hugetlb.c') diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 499cb72c74b1..995c8d65a95c 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -61,6 +61,9 @@ DEFINE_SPINLOCK(hugetlb_lock); 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 @@ static inline void unlock_or_release_subpool(struct hugepage_subpool *spool) 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 @@ struct hugepage_subpool *hugepage_new_subpool(long nr_blocks) 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; } -- cgit v1.2.3