[PATCH] tightening hugetlb strict accounting (a43a8c39) · Commits · 戴 / test

fs/hugetlbfs/inode.c

+9 −12

Original line number	Diff line number	Diff line
		@@ -59,7 +59,6 @@ static void huge_pagevec_release(struct pagevec *pvec)
		static int hugetlbfs_file_mmap(struct file file, struct vm_area_struct vma)
		{
		struct inode *inode = file->f_dentry->d_inode;
		struct hugetlbfs_inode_info *info = HUGETLBFS_I(inode);
		loff_t len, vma_len;
		int ret;

		@@ -87,8 +86,9 @@ static int hugetlbfs_file_mmap(struct file file, struct vm_area_struct vma)
		if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size)
		goto out;

		if (vma->vm_flags & VM_MAYSHARE)
		if (hugetlb_extend_reservation(info, len >> HPAGE_SHIFT) != 0)
		if (vma->vm_flags & VM_MAYSHARE &&
		hugetlb_reserve_pages(inode, vma->vm_pgoff >> (HPAGE_SHIFT-PAGE_SHIFT),
		len >> HPAGE_SHIFT))
		goto out;

		ret = 0;
		@@ -195,12 +195,8 @@ static void truncate_hugepages(struct inode *inode, loff_t lstart)
		const pgoff_t start = lstart >> HPAGE_SHIFT;
		struct pagevec pvec;
		pgoff_t next;
		int i;
		int i, freed = 0;

		hugetlb_truncate_reservation(HUGETLBFS_I(inode),
		lstart >> HPAGE_SHIFT);
		if (!mapping->nrpages)
		return;
		pagevec_init(&pvec, 0);
		next = start;
		while (1) {
		@@ -221,10 +217,12 @@ static void truncate_hugepages(struct inode *inode, loff_t lstart)
		truncate_huge_page(page);
		unlock_page(page);
		hugetlb_put_quota(mapping);
		freed++;
		}
		huge_pagevec_release(&pvec);
		}
		BUG_ON(!lstart && mapping->nrpages);
		hugetlb_unreserve_pages(inode, start, freed);
		}

		static void hugetlbfs_delete_inode(struct inode *inode)
		@@ -366,6 +364,7 @@ static struct inode hugetlbfs_get_inode(struct super_block sb, uid_t uid,
		inode->i_mapping->a_ops = &hugetlbfs_aops;
		inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info;
		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
		INIT_LIST_HEAD(&inode->i_mapping->private_list);
		info = HUGETLBFS_I(inode);
		mpol_shared_policy_init(&info->policy, MPOL_DEFAULT, NULL);
		switch (mode & S_IFMT) {
		@@ -538,7 +537,6 @@ static struct inode hugetlbfs_alloc_inode(struct super_block sb)
		hugetlbfs_inc_free_inodes(sbinfo);
		return NULL;
		}
		p->prereserved_hpages = 0;
		return &p->vfs_inode;
		}

		@@ -781,8 +779,7 @@ struct file *hugetlb_zero_setup(size_t size)
		goto out_file;

		error = -ENOMEM;
		if (hugetlb_extend_reservation(HUGETLBFS_I(inode),
		size >> HPAGE_SHIFT) != 0)
		if (hugetlb_reserve_pages(inode, 0, size >> HPAGE_SHIFT))
		goto out_inode;

		d_instantiate(dentry, inode);

include/linux/hugetlb.h

+2 −6

Original line number	Diff line number	Diff line
		@@ -23,6 +23,8 @@ int hugetlb_report_node_meminfo(int, char *);
		unsigned long hugetlb_total_pages(void);
		int hugetlb_fault(struct mm_struct mm, struct vm_area_struct vma,
		unsigned long address, int write_access);
		int hugetlb_reserve_pages(struct inode *inode, long from, long to);
		void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed);

		extern unsigned long max_huge_pages;
		extern const unsigned long hugetlb_zero, hugetlb_infinity;
		@@ -139,8 +141,6 @@ struct hugetlbfs_sb_info {

		struct hugetlbfs_inode_info {
		struct shared_policy policy;
		/* Protected by the (global) hugetlb_lock */
		unsigned long prereserved_hpages;
		struct inode vfs_inode;
		};

		@@ -157,10 +157,6 @@ static inline struct hugetlbfs_sb_info HUGETLBFS_SB(struct super_block sb)
		extern const struct file_operations hugetlbfs_file_operations;
		extern struct vm_operations_struct hugetlb_vm_ops;
		struct file *hugetlb_zero_setup(size_t);
		int hugetlb_extend_reservation(struct hugetlbfs_inode_info *info,
		unsigned long atleast_hpages);
		void hugetlb_truncate_reservation(struct hugetlbfs_inode_info *info,
		unsigned long atmost_hpages);
		int hugetlb_get_quota(struct address_space *mapping);
		void hugetlb_put_quota(struct address_space *mapping);

mm/hugetlb.c

+162 −120

Original line number	Diff line number	Diff line
		@@ -22,7 +22,7 @@
		#include "internal.h"

		const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
		static unsigned long nr_huge_pages, free_huge_pages, reserved_huge_pages;
		static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages;
		unsigned long max_huge_pages;
		static struct list_head hugepage_freelists[MAX_NUMNODES];
		static unsigned int nr_huge_pages_node[MAX_NUMNODES];
		@@ -123,39 +123,13 @@ static int alloc_fresh_huge_page(void)
		static struct page alloc_huge_page(struct vm_area_struct vma,
		unsigned long addr)
		{
		struct inode *inode = vma->vm_file->f_dentry->d_inode;
		struct page *page;
		int use_reserve = 0;
		unsigned long idx;

		spin_lock(&hugetlb_lock);

		if (vma->vm_flags & VM_MAYSHARE) {

		/* idx = radix tree index, i.e. offset into file in
		* HPAGE_SIZE units */
		idx = ((addr - vma->vm_start) >> HPAGE_SHIFT)
		+ (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));

		/* The hugetlbfs specific inode info stores the number
		* of "guaranteed available" (huge) pages. That is,
		* the first 'prereserved_hpages' pages of the inode
		* are either already instantiated, or have been
		* pre-reserved (by hugetlb_reserve_for_inode()). Here
		* we're in the process of instantiating the page, so
		* we use this to determine whether to draw from the
		* pre-reserved pool or the truly free pool. */
		if (idx < HUGETLBFS_I(inode)->prereserved_hpages)
		use_reserve = 1;
		}

		if (!use_reserve) {
		if (free_huge_pages <= reserved_huge_pages)
		if (vma->vm_flags & VM_MAYSHARE)
		resv_huge_pages--;
		else if (free_huge_pages <= resv_huge_pages)
		goto fail;
		} else {
		BUG_ON(reserved_huge_pages == 0);
		reserved_huge_pages--;
		}

		page = dequeue_huge_page(vma, addr);
		if (!page)
		@@ -166,95 +140,10 @@ static struct page alloc_huge_page(struct vm_area_struct vma,
		return page;

		fail:
		WARN_ON(use_reserve); /* reserved allocations shouldn't fail */
		spin_unlock(&hugetlb_lock);
		return NULL;
		}

		/* hugetlb_extend_reservation()
		*
		* Ensure that at least 'atleast' hugepages are, and will remain,
		* available to instantiate the first 'atleast' pages of the given
		* inode. If the inode doesn't already have this many pages reserved
		* or instantiated, set aside some hugepages in the reserved pool to
		* satisfy later faults (or fail now if there aren't enough, rather
		* than getting the SIGBUS later).
		*/
		int hugetlb_extend_reservation(struct hugetlbfs_inode_info *info,
		unsigned long atleast)
		{
		struct inode *inode = &info->vfs_inode;
		unsigned long change_in_reserve = 0;
		int ret = 0;

		spin_lock(&hugetlb_lock);
		read_lock_irq(&inode->i_mapping->tree_lock);

		if (info->prereserved_hpages >= atleast)
		goto out;

		/* Because we always call this on shared mappings, none of the
		* pages beyond info->prereserved_hpages can have been
		* instantiated, so we need to reserve all of them now. */
		change_in_reserve = atleast - info->prereserved_hpages;

		if ((reserved_huge_pages + change_in_reserve) > free_huge_pages) {
		ret = -ENOMEM;
		goto out;
		}

		reserved_huge_pages += change_in_reserve;
		info->prereserved_hpages = atleast;

		out:
		read_unlock_irq(&inode->i_mapping->tree_lock);
		spin_unlock(&hugetlb_lock);

		return ret;
		}

		/* hugetlb_truncate_reservation()
		*
		* This returns pages reserved for the given inode to the general free
		* hugepage pool. If the inode has any pages prereserved, but not
		* instantiated, beyond offset (atmost << HPAGE_SIZE), then release
		* them.
		*/
		void hugetlb_truncate_reservation(struct hugetlbfs_inode_info *info,
		unsigned long atmost)
		{
		struct inode *inode = &info->vfs_inode;
		struct address_space *mapping = inode->i_mapping;
		unsigned long idx;
		unsigned long change_in_reserve = 0;
		struct page *page;

		spin_lock(&hugetlb_lock);
		read_lock_irq(&inode->i_mapping->tree_lock);

		if (info->prereserved_hpages <= atmost)
		goto out;

		/* Count pages which were reserved, but not instantiated, and
		* which we can now release. */
		for (idx = atmost; idx < info->prereserved_hpages; idx++) {
		page = radix_tree_lookup(&mapping->page_tree, idx);
		if (!page)
		/* Pages which are already instantiated can't
		* be unreserved (and in fact have already
		* been removed from the reserved pool) */
		change_in_reserve++;
		}

		BUG_ON(reserved_huge_pages < change_in_reserve);
		reserved_huge_pages -= change_in_reserve;
		info->prereserved_hpages = atmost;

		out:
		read_unlock_irq(&inode->i_mapping->tree_lock);
		spin_unlock(&hugetlb_lock);
		}

		static int __init hugetlb_init(void)
		{
		unsigned long i;
		@@ -334,7 +223,7 @@ static unsigned long set_max_huge_pages(unsigned long count)
		return nr_huge_pages;

		spin_lock(&hugetlb_lock);
		count = max(count, reserved_huge_pages);
		count = max(count, resv_huge_pages);
		try_to_free_low(count);
		while (count < nr_huge_pages) {
		struct page *page = dequeue_huge_page(NULL, 0);
		@@ -365,7 +254,7 @@ int hugetlb_report_meminfo(char *buf)
		"Hugepagesize: %5lu kB\n",
		nr_huge_pages,
		free_huge_pages,
		reserved_huge_pages,
		resv_huge_pages,
		HPAGE_SIZE/1024);
		}

		@@ -754,3 +643,156 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
		flush_tlb_range(vma, start, end);
		}

		struct file_region {
		struct list_head link;
		long from;
		long to;
		};

		static long region_add(struct list_head *head, long f, long t)
		{
		struct file_region rg, nrg, *trg;

		/* Locate the region we are either in or before. */
		list_for_each_entry(rg, head, link)
		if (f <= rg->to)
		break;

		/* Round our left edge to the current segment if it encloses us. */
		if (f > rg->from)
		f = rg->from;

		/* Check for and consume any regions we now overlap with. */
		nrg = rg;
		list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
		if (&rg->link == head)
		break;
		if (rg->from > t)
		break;

		/* If this area reaches higher then extend our area to
		* include it completely. If this is not the first area
		* which we intend to reuse, free it. */
		if (rg->to > t)
		t = rg->to;
		if (rg != nrg) {
		list_del(&rg->link);
		kfree(rg);
		}
		}
		nrg->from = f;
		nrg->to = t;
		return 0;
		}

		static long region_chg(struct list_head *head, long f, long t)
		{
		struct file_region rg, nrg;
		long chg = 0;

		/* Locate the region we are before or in. */
		list_for_each_entry(rg, head, link)
		if (f <= rg->to)
		break;

		/* If we are below the current region then a new region is required.
		* Subtle, allocate a new region at the position but make it zero
		* size such that we can guarentee to record the reservation. */
		if (&rg->link == head \|\| t < rg->from) {
		nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
		if (nrg == 0)
		return -ENOMEM;
		nrg->from = f;
		nrg->to = f;
		INIT_LIST_HEAD(&nrg->link);
		list_add(&nrg->link, rg->link.prev);

		return t - f;
		}

		/* Round our left edge to the current segment if it encloses us. */
		if (f > rg->from)
		f = rg->from;
		chg = t - f;

		/* Check for and consume any regions we now overlap with. */
		list_for_each_entry(rg, rg->link.prev, link) {
		if (&rg->link == head)
		break;
		if (rg->from > t)
		return chg;

		/* We overlap with this area, if it extends futher than
		* us then we must extend ourselves. Account for its
		* existing reservation. */
		if (rg->to > t) {
		chg += rg->to - t;
		t = rg->to;
		}
		chg -= rg->to - rg->from;
		}
		return chg;
		}

		static long region_truncate(struct list_head *head, long end)
		{
		struct file_region rg, trg;
		long chg = 0;

		/* Locate the region we are either in or before. */
		list_for_each_entry(rg, head, link)
		if (end <= rg->to)
		break;
		if (&rg->link == head)
		return 0;

		/* If we are in the middle of a region then adjust it. */
		if (end > rg->from) {
		chg = rg->to - end;
		rg->to = end;
		rg = list_entry(rg->link.next, typeof(*rg), link);
		}

		/* Drop any remaining regions. */
		list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
		if (&rg->link == head)
		break;
		chg += rg->to - rg->from;
		list_del(&rg->link);
		kfree(rg);
		}
		return chg;
		}

		static int hugetlb_acct_memory(long delta)
		{
		int ret = -ENOMEM;

		spin_lock(&hugetlb_lock);
		if ((delta + resv_huge_pages) <= free_huge_pages) {
		resv_huge_pages += delta;
		ret = 0;
		}
		spin_unlock(&hugetlb_lock);
		return ret;
		}

		int hugetlb_reserve_pages(struct inode *inode, long from, long to)
		{
		long ret, chg;

		chg = region_chg(&inode->i_mapping->private_list, from, to);
		if (chg < 0)
		return chg;
		ret = hugetlb_acct_memory(chg);
		if (ret < 0)
		return ret;
		region_add(&inode->i_mapping->private_list, from, to);
		return 0;
		}

		void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
		{
		long chg = region_truncate(&inode->i_mapping->private_list, offset);
		hugetlb_acct_memory(freed - chg);
		}

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