From: Tang Yizhou <yizhou.tang@xxxxxxxxxx>
wbt_wait() no longer uses a spinlock as a parameter. Update the function
comments accordingly.
RWB_UNKNOWN_BUMP is used when we gradually adjust scale_steps toward the
center state, which is a value of 0.
Signed-off-by: Tang Yizhou <yizhou.tang@xxxxxxxxxx>
---
block/blk-wbt.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 6dfc659d22e2..8b73c0c11aec 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -136,8 +136,9 @@ enum {
RWB_MIN_WRITE_SAMPLES = 3,
/*
- * If we have this number of consecutive windows with not enough
- * information to scale up or down, scale up.
+ * If we have this number of consecutive windows without enough
+ * information to scale up or down, slowly return to center state
+ * (step == 0).
*/
RWB_UNKNOWN_BUMP = 5,
};
@@ -638,11 +639,7 @@ static void wbt_cleanup(struct rq_qos *rqos, struct bio *bio)
__wbt_done(rqos, flags);
}
-/*
- * May sleep, if we have exceeded the writeback limits. Caller can pass
- * in an irq held spinlock, if it holds one when calling this function.
- * If we do sleep, we'll release and re-grab it.
- */
+/* May sleep, if we have exceeded the writeback limits. */
static void wbt_wait(struct rq_qos *rqos, struct bio *bio)
{
struct rq_wb *rwb = RQWB(rqos);
--
2.25.1
