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/nommu.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'mm/nommu.c') diff --git a/mm/nommu.c b/mm/nommu.c index b20db4e22263..7296a5a280e7 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1250,7 +1250,8 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long len, unsigned long prot, unsigned long flags, - unsigned long pgoff) + unsigned long pgoff, + bool *populate) { struct vm_area_struct *vma; struct vm_region *region; @@ -1260,6 +1261,8 @@ unsigned long do_mmap_pgoff(struct file *file, kenter(",%lx,%lx,%lx,%lx,%lx", addr, len, prot, flags, pgoff); + *populate = false; + /* decide whether we should attempt the mapping, and if so what sort of * mapping */ ret = validate_mmap_request(file, addr, len, prot, flags, pgoff, -- cgit v1.2.3-55-g7522