diff options
| author | Michel Lespinasse <walken@google.com> | 2013-02-22 16:32:37 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-23 17:50:10 -0800 |
| commit | bebeb3d68b24bb4132d452c5707fe321208bcbcd (patch) | |
| tree | 6e609cb7323fb1b4b7026fa0e35867145a181094 /fs/aio.c | |
| parent | 940e7da5163029978c2f6b5bbe213607add59062 (diff) | |
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.c | 6 |
1 files changed, 5 insertions, 1 deletions
@@ -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; |