[PATCH] separate bdi congestion functions from queue congestion functions

Separate out the concept of "queue congestion" from "backing-dev congestion".
Congestion is a backing-dev concept, not a queue concept.

The blk_* congestion functions are retained, as wrappers around the core
backing-dev congestion functions.

This proper layering is needed so that NFS can cleanly use the congestion
functions, and so that CONFIG_BLOCK=n actually links.

Cc: "Thomas Maier" <balagi@justmail.de>
Cc: "Jens Axboe" <jens.axboe@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: David Howells <dhowells@redhat.com>
Cc: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 40db96a655d0..afee38f04d84 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -39,6 +39,7 @@
 #include <linux/stop_machine.h>
 #include <linux/sort.h>
 #include <linux/pfn.h>
+#include <linux/backing-dev.h>
 
 #include <asm/tlbflush.h>
 #include <asm/div64.h>
@@ -1050,7 +1051,7 @@ nofail_alloc:
                         if (page)
                                 goto got_pg;
                         if (gfp_mask & __GFP_NOFAIL) {
-                                blk_congestion_wait(WRITE, HZ/50);
+                                congestion_wait(WRITE, HZ/50);
                                 goto nofail_alloc;
                         }
                 }
@@ -1113,7 +1114,7 @@ rebalance:
                         do_retry = 1;
         }
         if (do_retry) {
-                blk_congestion_wait(WRITE, HZ/50);
+                congestion_wait(WRITE, HZ/50);
                 goto rebalance;
         }