aboutsummaryrefslogtreecommitdiff
path: root/fs/aio.c
diff options
context:
space:
mode:
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 /fs/aio.c
parent940e7da5163029978c2f6b5bbe213607add59062 (diff)
downloadlinux-linaro-stable-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 'fs/aio.c')
-rw-r--r--fs/aio.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 71f613cf4a85..82eec7c7b4bb 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -103,6 +103,7 @@ static int aio_setup_ring(struct kioctx *ctx)
unsigned nr_events = ctx->max_reqs;
unsigned long size;
int nr_pages;
+ bool populate;
/* Compensate for the ring buffer's head/tail overlap entry */
nr_events += 2; /* 1 is required, 2 for good luck */
@@ -129,7 +130,8 @@ static int aio_setup_ring(struct kioctx *ctx)
down_write(&ctx->mm->mmap_sem);
info->mmap_base = do_mmap_pgoff(NULL, 0, info->mmap_size,
PROT_READ|PROT_WRITE,
- MAP_ANONYMOUS|MAP_PRIVATE, 0);
+ MAP_ANONYMOUS|MAP_PRIVATE, 0,
+ &populate);
if (IS_ERR((void *)info->mmap_base)) {
up_write(&ctx->mm->mmap_sem);
info->mmap_size = 0;
@@ -147,6 +149,8 @@ static int aio_setup_ring(struct kioctx *ctx)
aio_free_ring(ctx);
return -EAGAIN;
}
+ if (populate)
+ mm_populate(info->mmap_base, info->mmap_size);
ctx->user_id = info->mmap_base;