block: change the request allocation/congestion logic to be sync/async based
This makes sure that we never wait on async IO for sync requests, instead
of doing the split on writes vs reads.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index bee52ab..0ec2c59 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -24,8 +24,8 @@
*/
enum bdi_state {
BDI_pdflush, /* A pdflush thread is working this device */
- BDI_write_congested, /* The write queue is getting full */
- BDI_read_congested, /* The read queue is getting full */
+ BDI_async_congested, /* The async (write) queue is getting full */
+ BDI_sync_congested, /* The sync queue is getting full */
BDI_unused, /* Available bits start here */
};
@@ -215,18 +215,18 @@
static inline int bdi_read_congested(struct backing_dev_info *bdi)
{
- return bdi_congested(bdi, 1 << BDI_read_congested);
+ return bdi_congested(bdi, 1 << BDI_sync_congested);
}
static inline int bdi_write_congested(struct backing_dev_info *bdi)
{
- return bdi_congested(bdi, 1 << BDI_write_congested);
+ return bdi_congested(bdi, 1 << BDI_async_congested);
}
static inline int bdi_rw_congested(struct backing_dev_info *bdi)
{
- return bdi_congested(bdi, (1 << BDI_read_congested)|
- (1 << BDI_write_congested));
+ return bdi_congested(bdi, (1 << BDI_sync_congested) |
+ (1 << BDI_async_congested));
}
void clear_bdi_congested(struct backing_dev_info *bdi, int rw);