hugetlb: Add hugetlb_dynamic_pool sysctl (54f9f80d) · Commits · 戴 / test

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>

include/linux/hugetlb.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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;

kernel/sysctl.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -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,

mm/hugetlb.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -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) {

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