From bebeb3d68b24bb4132d452c5707fe321208bcbcd Mon Sep 17 00:00:00 2001 From: Michel Lespinasse Date: Fri, 22 Feb 2013 16:32:37 -0800 Subject: mm: introduce mm_populate() for populating new vmas When creating new mappings using the MAP_POPULATE / MAP_LOCKED flags (or with MCL_FUTURE in effect), we want to populate the pages within the newly created vmas. This may take a while as we may have to read pages from disk, so ideally we want to do this outside of the write-locked mmap_sem region. This change introduces mm_populate(), which is used to defer populating such mappings until after the mmap_sem write lock has been released. This is implemented as a generalization of the former do_mlock_pages(), which accomplished the same task but was using during mlock() / mlockall(). Signed-off-by: Michel Lespinasse Reported-by: Andy Lutomirski Acked-by: Rik van Riel Tested-by: Andy Lutomirski Cc: Greg Ungerer Cc: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/util.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'mm/util.c') diff --git a/mm/util.c b/mm/util.c index c55e26b17d93..13467e043e9e 100644 --- a/mm/util.c +++ b/mm/util.c @@ -355,12 +355,16 @@ unsigned long vm_mmap_pgoff(struct file *file, unsigned long addr, { unsigned long ret; struct mm_struct *mm = current->mm; + bool populate; ret = security_mmap_file(file, prot, flag); if (!ret) { down_write(&mm->mmap_sem); - ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff); + ret = do_mmap_pgoff(file, addr, len, prot, flag, pgoff, + &populate); up_write(&mm->mmap_sem); + if (!IS_ERR_VALUE(ret) && populate) + mm_populate(ret, len); } return ret; } -- cgit v1.2.3-59-g8ed1b