diff options
| -rw-r--r-- | mm/hugetlb.c | 82 |
1 files changed, 41 insertions, 41 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 2c5c9ee4220d..a4dbba8965f3 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -716,6 +716,47 @@ unsigned long hugetlb_total_pages(void) return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE); } +static int hugetlb_acct_memory(long delta) +{ + int ret = -ENOMEM; + + spin_lock(&hugetlb_lock); + /* + * When cpuset is configured, it breaks the strict hugetlb page + * reservation as the accounting is done on a global variable. Such + * reservation is completely rubbish in the presence of cpuset because + * the reservation is not checked against page availability for the + * current cpuset. Application can still potentially OOM'ed by kernel + * with lack of free htlb page in cpuset that the task is in. + * Attempt to enforce strict accounting with cpuset is almost + * impossible (or too ugly) because cpuset is too fluid that + * task or memory node can be dynamically moved between cpusets. + * + * The change of semantics for shared hugetlb mapping with cpuset is + * undesirable. However, in order to preserve some of the semantics, + * we fall back to check against current free page availability as + * a best attempt and hopefully to minimize the impact of changing + * semantics that cpuset has. + */ + if (delta > 0) { + if (gather_surplus_pages(delta) < 0) + goto out; + + if (delta > cpuset_mems_nr(free_huge_pages_node)) { + return_unused_surplus_pages(delta); + goto out; + } + } + + ret = 0; + if (delta < 0) + return_unused_surplus_pages((unsigned long) -delta); + +out: + spin_unlock(&hugetlb_lock); + return ret; +} + /* * We cannot handle pagefaults against hugetlb pages at all. They cause * handle_mm_fault() to try to instantiate regular-sized pages in the @@ -1248,47 +1289,6 @@ static long region_truncate(struct list_head *head, long end) return chg; } -static int hugetlb_acct_memory(long delta) -{ - int ret = -ENOMEM; - - spin_lock(&hugetlb_lock); - /* - * When cpuset is configured, it breaks the strict hugetlb page - * reservation as the accounting is done on a global variable. Such - * reservation is completely rubbish in the presence of cpuset because - * the reservation is not checked against page availability for the - * current cpuset. Application can still potentially OOM'ed by kernel - * with lack of free htlb page in cpuset that the task is in. - * Attempt to enforce strict accounting with cpuset is almost - * impossible (or too ugly) because cpuset is too fluid that - * task or memory node can be dynamically moved between cpusets. - * - * The change of semantics for shared hugetlb mapping with cpuset is - * undesirable. However, in order to preserve some of the semantics, - * we fall back to check against current free page availability as - * a best attempt and hopefully to minimize the impact of changing - * semantics that cpuset has. - */ - if (delta > 0) { - if (gather_surplus_pages(delta) < 0) - goto out; - - if (delta > cpuset_mems_nr(free_huge_pages_node)) { - return_unused_surplus_pages(delta); - goto out; - } - } - - ret = 0; - if (delta < 0) - return_unused_surplus_pages((unsigned long) -delta); - -out: - spin_unlock(&hugetlb_lock); - return ret; -} - int hugetlb_reserve_pages(struct inode *inode, long from, long to) { long ret, chg; |