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authorAndrew Morton <akpm@osdl.org>2006-10-19 23:28:16 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-20 10:26:35 -0700
commit3fcfab16c5b86eaa3db3a9a31adba550c5b67141 (patch)
treebd348fa081b8fbec2c79fbf8f173a306d70b2b2c /include
parent79e2de4bc53d7ca2a8eedee49e4a92479b4b530e (diff)
[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>
Diffstat (limited to 'include')
-rw-r--r--include/linux/backing-dev.h7
-rw-r--r--include/linux/blkdev.h24
-rw-r--r--include/linux/writeback.h1
3 files changed, 27 insertions, 5 deletions
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index f7a1390d67f5..7011d6255593 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -10,6 +10,8 @@
#include <asm/atomic.h>
+struct page;
+
/*
* Bits in backing_dev_info.state
*/
@@ -88,6 +90,11 @@ static inline int bdi_rw_congested(struct backing_dev_info *bdi)
(1 << BDI_write_congested));
}
+void clear_bdi_congested(struct backing_dev_info *bdi, int rw);
+void set_bdi_congested(struct backing_dev_info *bdi, int rw);
+long congestion_wait(int rw, long timeout);
+void congestion_end(int rw);
+
#define bdi_cap_writeback_dirty(bdi) \
(!((bdi)->capabilities & BDI_CAP_NO_WRITEBACK))
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9575e3a5ff2a..7bfcde2d5578 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -651,8 +651,26 @@ extern void blk_recount_segments(request_queue_t *, struct bio *);
extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
extern int sg_scsi_ioctl(struct file *, struct request_queue *,
struct gendisk *, struct scsi_ioctl_command __user *);
-extern void blk_clear_queue_congested(request_queue_t *q, int rw);
-extern void blk_set_queue_congested(request_queue_t *q, int rw);
+
+/*
+ * A queue has just exitted congestion. Note this in the global counter of
+ * congested queues, and wake up anyone who was waiting for requests to be
+ * put back.
+ */
+static inline void blk_clear_queue_congested(request_queue_t *q, int rw)
+{
+ clear_bdi_congested(&q->backing_dev_info, rw);
+}
+
+/*
+ * A queue has just entered congestion. Flag that in the queue's VM-visible
+ * state flags and increment the global gounter of congested queues.
+ */
+static inline void blk_set_queue_congested(request_queue_t *q, int rw)
+{
+ set_bdi_congested(&q->backing_dev_info, rw);
+}
+
extern void blk_start_queue(request_queue_t *q);
extern void blk_stop_queue(request_queue_t *q);
extern void blk_sync_queue(struct request_queue *q);
@@ -767,10 +785,8 @@ extern int blk_queue_init_tags(request_queue_t *, int, struct blk_queue_tag *);
extern void blk_queue_free_tags(request_queue_t *);
extern int blk_queue_resize_tags(request_queue_t *, int);
extern void blk_queue_invalidate_tags(request_queue_t *);
-extern long blk_congestion_wait(int rw, long timeout);
extern struct blk_queue_tag *blk_init_tags(int);
extern void blk_free_tags(struct blk_queue_tag *);
-extern void blk_congestion_end(int rw);
static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
int tag)
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index a341c8032866..fc35e6bdfb93 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -85,7 +85,6 @@ int wakeup_pdflush(long nr_pages);
void laptop_io_completion(void);
void laptop_sync_completion(void);
void throttle_vm_writeout(void);
-void writeback_congestion_end(void);
/* These are exported to sysctl. */
extern int dirty_background_ratio;