[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, 3 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index af73c14f9d88..f05527bf792b 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1059,7 +1059,7 @@ unsigned long try_to_free_pages(struct zone **zones, gfp_t gfp_mask)
 
                 /* Take a nap, wait for some writeback to complete */
                 if (sc.nr_scanned && priority < DEF_PRIORITY - 2)
-                        blk_congestion_wait(WRITE, HZ/10);
+                        congestion_wait(WRITE, HZ/10);
         }
         /* top priority shrink_caches still had more to do? don't OOM, then */
         if (!sc.all_unreclaimable)
@@ -1214,7 +1214,7 @@ scan:
                  * another pass across the zones.
                  */
                 if (total_scanned && priority < DEF_PRIORITY - 2)
-                        blk_congestion_wait(WRITE, HZ/10);
+                        congestion_wait(WRITE, HZ/10);
 
                 /*
                  * We do this so kswapd doesn't build up large priorities for
@@ -1458,7 +1458,7 @@ unsigned long shrink_all_memory(unsigned long nr_pages)
                                 goto out;
 
                         if (sc.nr_scanned && prio < DEF_PRIORITY - 2)
-                                blk_congestion_wait(WRITE, HZ / 10);
+                                congestion_wait(WRITE, HZ / 10);
                 }
 
                 lru_pages = 0;