Commit 2b26736c authored by Andy Whitcroft's avatar Andy Whitcroft Committed by Linus Torvalds
Browse files

allocate structures for reservation tracking in hugetlbfs outside of spinlocks v2 



[Andrew this should replace the previous version which did not check
the returns from the region prepare for errors.  This has been tested by
us and Gerald and it looks good.

Bah, while reviewing the locking based on your previous email I spotted
that we need to check the return from the vma_needs_reservation call for
allocation errors.  Here is an updated patch to correct this.  This passes
testing here.]

Signed-off-by: default avatarAndy Whitcroft <apw@shadowen.org>
Tested-by: default avatarGerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 57303d80

mm/hugetlb.c

+11 −4
Original line number Diff line number Diff line
@@ -1949,7 +1949,10 @@ retry: 
	 * the spinlock.

	 */

	if (write_access && !(vma->vm_flags & VM_SHARED))

		vma_needs_reservation(h, vma, address);

		if (vma_needs_reservation(h, vma, address) < 0) {

			ret = VM_FAULT_OOM;

			goto backout_unlocked;

		}



	spin_lock(&mm->page_table_lock);

	size = i_size_read(mapping->host) >> huge_page_shift(h);
@@ -1976,6 +1979,7 @@ out: 


backout:

	spin_unlock(&mm->page_table_lock);

backout_unlocked:

	unlock_page(page);

	put_page(page);

	goto out;
@@ -2004,8 +2008,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 
	entry = huge_ptep_get(ptep);

	if (huge_pte_none(entry)) {

		ret = hugetlb_no_page(mm, vma, address, ptep, write_access);

		mutex_unlock(&hugetlb_instantiation_mutex);

		return ret;

		goto out_unlock;

	}



	ret = 0;
@@ -2019,7 +2022,10 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 
	 * consumed.

	 */

	if (write_access && !pte_write(entry)) {

		vma_needs_reservation(h, vma, address);

		if (vma_needs_reservation(h, vma, address) < 0) {

			ret = VM_FAULT_OOM;

			goto out_unlock;

		}



		if (!(vma->vm_flags & VM_SHARED))

			pagecache_page = hugetlbfs_pagecache_page(h,
@@ -2039,6 +2045,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, 
		put_page(pagecache_page);

	}



out_unlock:

	mutex_unlock(&hugetlb_instantiation_mutex);



	return ret;

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