From: Nishanth Aravamudan Date: Fri, 8 Feb 2008 12:18:18 +0000 (-0800) Subject: hugetlb: add locking for overcommit sysctl X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=a3d0c6aa1bb342b9b2c7b123b52ac2f48a4d4d0a;p=openwrt%2Fstaging%2Fblogic.git hugetlb: add locking for overcommit sysctl When I replaced hugetlb_dynamic_pool with nr_overcommit_hugepages I used proc_doulongvec_minmax() directly. However, hugetlb.c's locking rules require that all counter modifications occur under the hugetlb_lock. Add a callback into the hugetlb code similar to the one for nr_hugepages. Grab the lock around the manipulation of nr_overcommit_hugepages in proc_doulongvec_minmax(). Signed-off-by: Nishanth Aravamudan Acked-by: Adam Litke Cc: David Gibson Cc: William Lee Irwin III Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 30d606afcafe..7ca198b379af 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -17,6 +17,7 @@ static inline int is_vm_hugetlb_page(struct vm_area_struct *vma) } int hugetlb_sysctl_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *); +int hugetlb_overcommit_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *); int hugetlb_treat_movable_handler(struct ctl_table *, int, struct file *, void __user *, size_t *, loff_t *); int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *); int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *, struct page **, struct vm_area_struct **, unsigned long *, int *, int, int); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8c98d8147d88..9dadc9d88a03 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -982,7 +982,7 @@ static struct ctl_table vm_table[] = { .data = &nr_overcommit_huge_pages, .maxlen = sizeof(nr_overcommit_huge_pages), .mode = 0644, - .proc_handler = &proc_doulongvec_minmax, + .proc_handler = &hugetlb_overcommit_handler, }, #endif { diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 1a5642074e34..d9a380312467 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -605,6 +605,16 @@ int hugetlb_treat_movable_handler(struct ctl_table *table, int write, return 0; } +int hugetlb_overcommit_handler(struct ctl_table *table, int write, + struct file *file, void __user *buffer, + size_t *length, loff_t *ppos) +{ + spin_lock(&hugetlb_lock); + proc_doulongvec_minmax(table, write, file, buffer, length, ppos); + spin_unlock(&hugetlb_lock); + return 0; +} + #endif /* CONFIG_SYSCTL */ int hugetlb_report_meminfo(char *buf)