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authorMichel Lespinasse <walken@google.com>2013-02-22 16:32:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-23 17:50:10 -0800
commitbebeb3d68b24bb4132d452c5707fe321208bcbcd (patch)
tree6e609cb7323fb1b4b7026fa0e35867145a181094 /mm/util.c
parent940e7da5163029978c2f6b5bbe213607add59062 (diff)
downloadlinux-bebeb3d68b24bb4132d452c5707fe321208bcbcd.tar.gz
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 <walken@google.com> Reported-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Rik van Riel <riel@redhat.com> Tested-by: Andy Lutomirski <luto@amacapital.net> Cc: Greg Ungerer <gregungerer@westnet.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/util.c')
-rw-r--r--mm/util.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/mm/util.c b/mm/util.c
index c55e26b17d9..13467e043e9 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;
}