Messages in this thread Patch in this message | | | Subject | [PATCH 2/2] hugetlb: synchronize alloc with page cache insert | From | Adam Litke <> | Date | Wed, 11 Jan 2006 16:24:23 -0600 |
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On Wed, 2006-01-11 at 16:02 -0600, Adam Litke wrote: > here). The patch doesn't completely close the race (there is a much > smaller window without the zeroing though). The next patch should close > the race window completely.
My only concern is if I am using the correct lock for the job here.
hugetlb.c | 14 ++++++++++---- 1 files changed, 10 insertions(+), 4 deletions(-) diff -upN reference/mm/hugetlb.c current/mm/hugetlb.c --- reference/mm/hugetlb.c +++ current/mm/hugetlb.c @@ -445,6 +445,7 @@ int hugetlb_no_page(struct mm_struct *mm struct page *page; struct address_space *mapping; pte_t new_pte; + int shared = vma->vm_flags & VM_SHARED; mapping = vma->vm_file->f_mapping; idx = ((address - vma->vm_start) >> HPAGE_SHIFT) @@ -454,26 +455,31 @@ int hugetlb_no_page(struct mm_struct *mm * Use page lock to guard against racing truncation * before we get page_table_lock. */ -retry: page = find_lock_page(mapping, idx); if (!page) { if (hugetlb_get_quota(mapping)) goto out; + + if (shared) + spin_lock(&mapping->host->i_lock); + page = alloc_unzeroed_huge_page(vma, address); if (!page) { hugetlb_put_quota(mapping); + if (shared) + spin_unlock(&mapping->host->i_lock); goto out; } - if (vma->vm_flags & VM_SHARED) { + if (shared) { int err; err = add_to_page_cache(page, mapping, idx, GFP_KERNEL); + spin_unlock(&mapping->host->i_lock); if (err) { put_page(page); hugetlb_put_quota(mapping); - if (err == -EEXIST) - goto retry; + BUG_ON(-EEXIST); goto out; } } else
-- Adam Litke - (agl at us.ibm.com) IBM Linux Technology Center
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