Fix congestion_wait() sync/async vs read/write confusion
Commit 1faa16d22877f4839bd433547d770c676d1d964c accidentally broke
the bdi congestion wait queue logic, causing us to wait on congestion
for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 493b468..c86edd2 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -283,7 +283,6 @@
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])
};
-
void clear_bdi_congested(struct backing_dev_info *bdi, int sync)
{
enum bdi_state bit;
@@ -308,18 +307,18 @@
/**
* congestion_wait - wait for a backing_dev to become uncongested
- * @rw: READ or WRITE
+ * @sync: SYNC or ASYNC IO
* @timeout: timeout in jiffies
*
* Waits for up to @timeout jiffies for a backing_dev (any backing_dev) to exit
* write congestion. If no backing_devs are congested then just wait for the
* next write to be completed.
*/
-long congestion_wait(int rw, long timeout)
+long congestion_wait(int sync, long timeout)
{
long ret;
DEFINE_WAIT(wait);
- wait_queue_head_t *wqh = &congestion_wqh[rw];
+ wait_queue_head_t *wqh = &congestion_wqh[sync];
prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
ret = io_schedule_timeout(timeout);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e2fa20d..e717964 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1973,7 +1973,7 @@
if (!progress) {
nr_retries--;
/* maybe some writeback is necessary */
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
}
}
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 7687879..81627eb 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -575,7 +575,7 @@
if (pages_written >= write_chunk)
break; /* We've done our duty */
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
}
if (bdi_nr_reclaimable + bdi_nr_writeback < bdi_thresh &&
@@ -669,7 +669,7 @@
if (global_page_state(NR_UNSTABLE_NFS) +
global_page_state(NR_WRITEBACK) <= dirty_thresh)
break;
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
/*
* The caller might hold locks which can prevent IO completion
@@ -715,7 +715,7 @@
if (wbc.nr_to_write > 0 || wbc.pages_skipped > 0) {
/* Wrote less than expected */
if (wbc.encountered_congestion || wbc.more_io)
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
else
break;
}
@@ -787,7 +787,7 @@
writeback_inodes(&wbc);
if (wbc.nr_to_write > 0) {
if (wbc.encountered_congestion || wbc.more_io)
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
else
break; /* All the old data is written */
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index ad7cd1c..a35eeab 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1666,7 +1666,7 @@
preferred_zone, migratetype);
if (!page && gfp_mask & __GFP_NOFAIL)
- congestion_wait(WRITE, HZ/50);
+ congestion_wait(BLK_RW_ASYNC, HZ/50);
} while (!page && (gfp_mask & __GFP_NOFAIL));
return page;
@@ -1831,7 +1831,7 @@
pages_reclaimed += did_some_progress;
if (should_alloc_retry(gfp_mask, order, pages_reclaimed)) {
/* Wait for some write requests to complete then retry */
- congestion_wait(WRITE, HZ/50);
+ congestion_wait(BLK_RW_ASYNC, HZ/50);
goto rebalance;
}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5415526..dea7abd 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1104,7 +1104,7 @@
*/
if (nr_freed < nr_taken && !current_is_kswapd() &&
lumpy_reclaim) {
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
/*
* The attempt at page out may have made some
@@ -1721,7 +1721,7 @@
/* Take a nap, wait for some writeback to complete */
if (sc->nr_scanned && priority < DEF_PRIORITY - 2)
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
}
/* top priority shrink_zones still had more to do? don't OOM, then */
if (!sc->all_unreclaimable && scanning_global_lru(sc))
@@ -1960,7 +1960,7 @@
* another pass across the zones.
*/
if (total_scanned && priority < DEF_PRIORITY - 2)
- congestion_wait(WRITE, HZ/10);
+ congestion_wait(BLK_RW_ASYNC, HZ/10);
/*
* We do this so kswapd doesn't build up large priorities for
@@ -2233,7 +2233,7 @@
goto out;
if (sc.nr_scanned && prio < DEF_PRIORITY - 2)
- congestion_wait(WRITE, HZ / 10);
+ congestion_wait(BLK_RW_ASYNC, HZ / 10);
}
}