diff options
| author | Hugh Dickins | 2009-12-14 17:58:47 -0800 |
|---|---|---|
| committer | Linus Torvalds | 2009-12-15 08:53:16 -0800 |
| commit | aaa468653b4a0d11c603c48d716f765177a5a9e4 (patch) | |
| tree | 3cb8c9232dd405001fa38d5519937c5e6c6f32ab /mm/shmem.c | |
| parent | 570a335b8e22579e2a51a68136d2b1f907a20eec (diff) | |
swap_info: note SWAP_MAP_SHMEM
While we're fiddling with the swap_map values, let's assign a particular
value to shmem/tmpfs swap pages: their swap counts are never incremented,
and it helps swapoff's try_to_unuse() a little if it can immediately
distinguish those pages from process pages.
Since we've no use for SWAP_MAP_BAD | COUNT_CONTINUED,
we might as well use that 0xbf value for SWAP_MAP_SHMEM.
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/shmem.c')
| -rw-r--r-- | mm/shmem.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 356dd99566ec..4fb41c83daca 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1017,7 +1017,14 @@ int shmem_unuse(swp_entry_t entry, struct page *page) goto out; } mutex_unlock(&shmem_swaplist_mutex); -out: return found; /* 0 or 1 or -ENOMEM */ + /* + * Can some race bring us here? We've been holding page lock, + * so I think not; but would rather try again later than BUG() + */ + unlock_page(page); + page_cache_release(page); +out: + return (found < 0) ? found : 0; } /* @@ -1080,7 +1087,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) else inode = NULL; spin_unlock(&info->lock); - swap_duplicate(swap); + swap_shmem_alloc(swap); BUG_ON(page_mapped(page)); page_cache_release(page); /* pagecache ref */ swap_writepage(page, wbc); |