enic: add devcmd2 resources

[cascardo/linux.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index e61445d..8286938 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -973,22 +973,18 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                 *    caller can stall after page list has been processed.
                 *
                 * 2) Global or new memcg reclaim encounters a page that is
-                *    not marked for immediate reclaim or the caller does not
-                *    have __GFP_IO. In this case mark the page for immediate
+                *    not marked for immediate reclaim, or the caller does not
+                *    have __GFP_FS (or __GFP_IO if it's simply going to swap,
+                *    not to fs). In this case mark the page for immediate
                 *    reclaim and continue scanning.
                 *
-                *    __GFP_IO is checked  because a loop driver thread might
+                *    Require may_enter_fs because we would wait on fs, which
+                *    may not have submitted IO yet. And the loop driver might
                 *    enter reclaim, and deadlock if it waits on a page for
                 *    which it is needed to do the write (loop masks off
                 *    __GFP_IO|__GFP_FS for this reason); but more thought
                 *    would probably show more reasons.
                 *
-                *    Don't require __GFP_FS, since we're not going into the
-                *    FS, just waiting on its writeback completion. Worryingly,
-                *    ext4 gfs2 and xfs allocate pages with
-                *    grab_cache_page_write_begin(,,AOP_FLAG_NOFS), so testing
-                *    may_enter_fs here is liable to OOM on them.
-                *
                 * 3) Legacy memcg encounters a page that is not already marked
                 *    PageReclaim. memcg does not have any dirty pages
                 *    throttling so we could easily OOM just because too many
@@ -1005,7 +1001,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 
                        /* Case 2 above */
                        } else if (sane_reclaim(sc) ||
-                           !PageReclaim(page) || !(sc->gfp_mask & __GFP_IO)) {
+                           !PageReclaim(page) || !may_enter_fs) {
                                /*
                                 * This is slightly racy - end_page_writeback()
                                 * might have just cleared PageReclaim, then