diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 11 | ||||
| -rw-r--r-- | mm/shmem.c | 17 |
2 files changed, 17 insertions, 11 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); diff --git a/mm/shmem.c b/mm/shmem.c index e64fa726a79..5a81b1ee4f7 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1773,32 +1773,27 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s return 0; } -static int shmem_follow_link_inline(struct dentry *dentry, struct nameidata *nd) +static void *shmem_follow_link_inline(struct dentry *dentry, struct nameidata *nd) { nd_set_link(nd, (char *)SHMEM_I(dentry->d_inode)); - return 0; + return NULL; } -static int shmem_follow_link(struct dentry *dentry, struct nameidata *nd) +static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd) { struct page *page = NULL; int res = shmem_getpage(dentry->d_inode, 0, &page, SGP_READ, NULL); nd_set_link(nd, res ? ERR_PTR(res) : kmap(page)); - return 0; + return page; } -static void shmem_put_link(struct dentry *dentry, struct nameidata *nd) +static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) { if (!IS_ERR(nd_get_link(nd))) { - struct page *page; - - page = find_get_page(dentry->d_inode->i_mapping, 0); - if (!page) - BUG(); + struct page *page = cookie; kunmap(page); mark_page_accessed(page); page_cache_release(page); - page_cache_release(page); } } |