diff options
author | Jeff Garzik <jgarzik@pobox.com> | 2005-09-01 18:02:01 -0400 |
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committer | Jeff Garzik <jgarzik@pobox.com> | 2005-09-01 18:02:01 -0400 |
commit | e3ee3b78f83688a0ae4315e8be71b2eac559904a (patch) | |
tree | deb03bcdd020262af450ed23382d7c921263f5cf /mm | |
parent | 91cb70c1769d9b72dd1efe40c31f01005820b09e (diff) | |
parent | 6b39374a27eb4be7e9d82145ae270ba02ea90dc8 (diff) |
/spare/repo/netdev-2.6 branch 'master'
Diffstat (limited to 'mm')
-rw-r--r-- | mm/memory.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c index e046b7e4b53..a596c117224 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -498,6 +498,17 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, unsigned long addr = vma->vm_start; unsigned long end = vma->vm_end; + /* + * Don't copy ptes where a page fault will fill them correctly. + * Fork becomes much lighter when there are big shared or private + * readonly mappings. The tradeoff is that copy_page_range is more + * efficient than faulting. + */ + if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_RESERVED))) { + if (!vma->anon_vma) + return 0; + } + if (is_vm_hugetlb_page(vma)) return copy_hugetlb_page_range(dst_mm, src_mm, vma); |