[PATCH 2/6] writeback: remove unused nonblocking and congestion checks (write_cache_pages)

[Wu Fengguang <fengguang.wu@gmail.com>]

[-- Attachment #1: writeback-remove-congested-checks-linux_mm_page-writeback.patch --]
[-- Type: text/plain, Size: 1382 bytes --]

No one is calling wb_writeback and write_cache_pages with
wbc.nonblocking=1 any more. And lumpy pageout will want to do
nonblocking writeback without the congestion wait.

CC: Chris Mason <chris.mason@oracle.com>
CC: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
 mm/page-writeback.c |   12 ------------
 1 file changed, 12 deletions(-)

--- linux.orig/mm/page-writeback.c	2009-11-27 16:35:00.000000000 +0800
+++ linux/mm/page-writeback.c	2009-11-27 18:55:00.000000000 +0800
@@ -821,7 +821,6 @@ int write_cache_pages(struct address_spa
 		      struct writeback_control *wbc, writepage_t writepage,
 		      void *data)
 {
-	struct backing_dev_info *bdi = mapping->backing_dev_info;
 	int ret = 0;
 	int done = 0;
 	struct pagevec pvec;
@@ -834,11 +833,6 @@ int write_cache_pages(struct address_spa
 	int range_whole = 0;
 	long nr_to_write = wbc->nr_to_write;
 
-	if (wbc->nonblocking && bdi_write_congested(bdi)) {
-		wbc->encountered_congestion = 1;
-		return 0;
-	}
-
 	pagevec_init(&pvec, 0);
 	if (wbc->range_cyclic) {
 		writeback_index = mapping->writeback_index; /* prev offset */
@@ -957,12 +951,6 @@ continue_unlock:
 					break;
 				}
 			}
-
-			if (wbc->nonblocking && bdi_write_congested(bdi)) {
-				wbc->encountered_congestion = 1;
-				done = 1;
-				break;
-			}
 		}
 		pagevec_release(&pvec);
 		cond_resched();