[PATCH] CONFIG_BLOCK: blk_congestion_wait() fix

Don't just do nothing: it'll cause busywaits all over writeback and page reclaim. For now, take a fixed-length nap. Will improve when NFS starts waking up throttled processes. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>

[PATCH] CONFIG_BLOCK: blk_congestion_wait() fix
Don't just do nothing: it'll cause busywaits all over writeback and page reclaim. For now, take a fixed-length nap. Will improve when NFS starts waking up throttled processes. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Andrew Morton · Jens Axboe
1 parent 5e6d12b2c8
Showing 1 changed file with 5 additions and 2 deletions Side-by-side Diff
include/linux/blkdev.h
 #ifndef _LINUX_BLKDEV_H
 #define _LINUX_BLKDEV_H
  
+#include <linux/sched.h>
 #include <linux/major.h>
 #include <linux/genhd.h>
 #include <linux/list.h>
@@ -848,7 +849,7 @@
  
 static inline long blk_congestion_wait(int rw, long timeout)
 {
-	return timeout;
+	return io_schedule_timeout(timeout);
 }
  
 static inline long nr_blockdev_pages(void)
@@ -856,7 +857,9 @@
 	return 0;
 }
  
-static inline void exit_io_context(void) {}
+static inline void exit_io_context(void)
+{
+}
  
 #endif /* CONFIG_BLOCK */
1	1	#ifndef _LINUX_BLKDEV_H
2	2	#define _LINUX_BLKDEV_H
3	3
	4	+#include <linux/sched.h>
4	5	#include <linux/major.h>
5	6	#include <linux/genhd.h>
6	7	#include <linux/list.h>
...	...	@@ -848,7 +849,7 @@
848	849
849	850	static inline long blk_congestion_wait(int rw, long timeout)
850	851	{
851		- return timeout;
	852	+ return io_schedule_timeout(timeout);
852	853	}
853	854
854	855	static inline long nr_blockdev_pages(void)
...	...	@@ -856,7 +857,9 @@
856	857	return 0;
857	858	}
858	859
859		-static inline void exit_io_context(void) {}
	860	+static inline void exit_io_context(void)
	861	+{
	862	+}
860	863
861	864	#endif /* CONFIG_BLOCK */
862	865