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authorAdam Litke <agl@us.ibm.com>2007-10-16 01:26:20 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 09:43:02 -0700
commit54f9f80d6543fb7b157d3b11e2e7911dc1379790 (patch)
tree70d34e45f4d1694609db25da0ccad90b4b0ad473
parente4e574b767ba63101cfda2b42d72f38546319297 (diff)
hugetlb: Add hugetlb_dynamic_pool sysctl
The maximum size of the huge page pool can be controlled using the overall size of the hugetlb filesystem (via its 'size' mount option). However in the common case the this will not be set as the pool is traditionally fixed in size at boot time. In order to maintain the expected semantics, we need to prevent the pool expanding by default. This patch introduces a new sysctl controlling dynamic pool resizing. When this is enabled the pool will expand beyond its base size up to the size of the hugetlb filesystem. It is disabled by default. Signed-off-by: Adam Litke <agl@us.ibm.com> Acked-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Dave McCracken <dave.mccracken@oracle.com> Cc: William Irwin <bill.irwin@oracle.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Ken Chen <kenchen@google.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/hugetlb.h1
-rw-r--r--kernel/sysctl.c8
-rw-r--r--mm/hugetlb.c5
3 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 3a19b032c0e..ea0f50bfbe0 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -33,6 +33,7 @@ void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed);
extern unsigned long max_huge_pages;
extern unsigned long hugepages_treat_as_movable;
+extern int hugetlb_dynamic_pool;
extern const unsigned long hugetlb_zero, hugetlb_infinity;
extern int sysctl_hugetlb_shm_group;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index ec14aa8ac51..96efbb85999 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -880,6 +880,14 @@ static ctl_table vm_table[] = {
.mode = 0644,
.proc_handler = &hugetlb_treat_movable_handler,
},
+ {
+ .ctl_name = CTL_UNNUMBERED,
+ .procname = "hugetlb_dynamic_pool",
+ .data = &hugetlb_dynamic_pool,
+ .maxlen = sizeof(hugetlb_dynamic_pool),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
#endif
{
.ctl_name = VM_LOWMEM_RESERVE_RATIO,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 31bbca6b2c9..efd78527ad1 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -31,6 +31,7 @@ static unsigned int free_huge_pages_node[MAX_NUMNODES];
static unsigned int surplus_huge_pages_node[MAX_NUMNODES];
static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
unsigned long hugepages_treat_as_movable;
+int hugetlb_dynamic_pool;
/*
* Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
@@ -201,6 +202,10 @@ static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
{
struct page *page;
+ /* Check if the dynamic pool is enabled */
+ if (!hugetlb_dynamic_pool)
+ return NULL;
+
page = alloc_pages(htlb_alloc_mask|__GFP_COMP|__GFP_NOWARN,
HUGETLB_PAGE_ORDER);
if (page) {