blk-mq: account higher order dispatch
We currently account a '0' dispatch, and anything above that still falls
below the range set by BLK_MQ_MAX_DISPATCH_ORDER. If we dispatch more,
we don't account it.
Change the last bucket to be inclusive of anything above the range we
track, and have the sysfs file reflect that by including a '+' in the
output:
$ cat /sys/block/nvme0n1/mq/0/dispatched
0 1006
1 20229
2 1
4 0
8 0
16 0
32+ 0
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index ac5160e..3c385b1 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -208,12 +208,14 @@
page += sprintf(page, "%8u\t%lu\n", 0U, hctx->dispatched[0]);
- for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER; i++) {
- unsigned long d = 1U << (i - 1);
+ for (i = 1; i < BLK_MQ_MAX_DISPATCH_ORDER - 1; i++) {
+ unsigned int d = 1U << (i - 1);
- page += sprintf(page, "%8lu\t%lu\n", d, hctx->dispatched[i]);
+ page += sprintf(page, "%8u\t%lu\n", d, hctx->dispatched[i]);
}
+ page += sprintf(page, "%8u+\t%lu\n", 1U << (i - 1),
+ hctx->dispatched[i]);
return page - start_page;
}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7ddc796..0cb9362 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -789,6 +789,14 @@
}
}
+static inline unsigned int queued_to_index(unsigned int queued)
+{
+ if (!queued)
+ return 0;
+
+ return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1);
+}
+
/*
* Run this hardware queue, pulling any software queues mapped to it in.
* Note that this function currently has various problems around ordering
@@ -877,10 +885,7 @@
dptr = &driver_list;
}
- if (!queued)
- hctx->dispatched[0]++;
- else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1)))
- hctx->dispatched[ilog2(queued) + 1]++;
+ hctx->dispatched[queued_to_index(queued)]++;
/*
* Any items that need requeuing? Stuff them into hctx->dispatch,