| From stable-bounces@linux.kernel.org Fri Feb 8 04:19:17 2008 |
| From: Nishanth Aravamudan <nacc@us.ibm.com> |
| Date: Fri, 08 Feb 2008 04:18:18 -0800 |
| Subject: hugetlb: add locking for overcommit sysctl |
| To: torvalds@linux-foundation.org |
| Cc: wli@holomorphy.com, agl@us.ibm.com, nacc@us.ibm.com, akpm@linux-foundation.org, stable@kernel.org, david@gibson.dropbear.id.au |
| Message-ID: <200802081217.m18CHxwe023557@imap1.linux-foundation.org> |
| |
| |
| From: Nishanth Aravamudan <nacc@us.ibm.com> |
| |
| patch a3d0c6aa1bb342b9b2c7b123b52ac2f48a4d4d0a in mainline. |
| |
| 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 <nacc@us.ibm.com> |
| Acked-by: Adam Litke <agl@us.ibm.com> |
| Cc: David Gibson <david@gibson.dropbear.id.au> |
| Cc: William Lee Irwin III <wli@holomorphy.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| |
| --- |
| include/linux/hugetlb.h | 1 + |
| kernel/sysctl.c | 2 +- |
| mm/hugetlb.c | 10 ++++++++++ |
| 3 files changed, 12 insertions(+), 1 deletion(-) |
| |
| --- a/include/linux/hugetlb.h |
| +++ b/include/linux/hugetlb.h |
| @@ -17,6 +17,7 @@ static inline int is_vm_hugetlb_page(str |
| } |
| |
| 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); |
| --- a/kernel/sysctl.c |
| +++ b/kernel/sysctl.c |
| @@ -910,7 +910,7 @@ 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 |
| { |
| --- a/mm/hugetlb.c |
| +++ b/mm/hugetlb.c |
| @@ -605,6 +605,16 @@ int hugetlb_treat_movable_handler(struct |
| 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) |
