This patch adds two new fields to BlockDeviceTimedStats that track the
average number of pending read and write requests for a block device.
The values are calculated for the period of time defined for that
interval.
Signed-off-by: Alberto Garcia
---
block/accounting.c | 12
block/qapi.c | 5 +
include/block/accounting.h | 2 ++
include/qemu/timed-average.h | 1 +
qapi/block-core.json | 9 -
qmp-commands.hx | 6 ++
util/timed-average.c | 17 +
7 files changed, 51 insertions(+), 1 deletion(-)
diff --git a/block/accounting.c b/block/accounting.c
index 61de8ce..a941931 100644
--- a/block/accounting.c
+++ b/block/accounting.c
@@ -143,3 +143,15 @@ int64_t block_acct_idle_time_ns(BlockAcctStats *stats)
{
return qemu_clock_get_ns(clock_type) - stats->last_access_time_ns;
}
+
+double block_acct_queue_depth(BlockAcctTimedStats *stats,
+ enum BlockAcctType type)
+{
+uint64_t sum, elapsed;
+
+assert(type < BLOCK_MAX_IOTYPE);
+
+sum = timed_average_sum(&stats->latency[type], &elapsed);
+
+return (double) sum / elapsed;
+}
diff --git a/block/qapi.c b/block/qapi.c
index 4baf6e1..99d5303 100644
--- a/block/qapi.c
+++ b/block/qapi.c
@@ -402,6 +402,11 @@ static BlockStats *bdrv_query_stats(const BlockDriverState
*bs,
dev_stats->min_flush_latency_ns = timed_average_min(fl);
dev_stats->max_flush_latency_ns = timed_average_max(fl);
dev_stats->avg_flush_latency_ns = timed_average_avg(fl);
+
+dev_stats->avg_rd_queue_depth =
+block_acct_queue_depth(ts, BLOCK_ACCT_READ);
+dev_stats->avg_wr_queue_depth =
+block_acct_queue_depth(ts, BLOCK_ACCT_WRITE);
}
}
diff --git a/include/block/accounting.h b/include/block/accounting.h
index 09605bb..f41ddde 100644
--- a/include/block/accounting.h
+++ b/include/block/accounting.h
@@ -78,5 +78,7 @@ void block_acct_invalid(BlockAcctStats *stats, enum
BlockAcctType type);
void block_acct_merge_done(BlockAcctStats *stats, enum BlockAcctType type,
int num_requests);
int64_t block_acct_idle_time_ns(BlockAcctStats *stats);
+double block_acct_queue_depth(BlockAcctTimedStats *stats,
+ enum BlockAcctType type);
#endif
diff --git a/include/qemu/timed-average.h b/include/qemu/timed-average.h
index f1cdddc..364bf88 100644
--- a/include/qemu/timed-average.h
+++ b/include/qemu/timed-average.h
@@ -59,5 +59,6 @@ void timed_average_account(TimedAverage *ta, uint64_t value);
uint64_t timed_average_min(TimedAverage *ta);
uint64_t timed_average_avg(TimedAverage *ta);
uint64_t timed_average_max(TimedAverage *ta);
+uint64_t timed_average_sum(TimedAverage *ta, uint64_t *elapsed);
#endif
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 741f7e6..e32b523 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -450,6 +450,12 @@
# @avg_flush_latency_ns: Average latency of flush operations in the
#defined interval, in nanoseconds.
#
+# @avg_rd_queue_depth: Average number of pending read operations
+# in the defined interval.
+#
+# @avg_wr_queue_depth: Average number of pending write operations
+# in the defined interval.
+#
# Since: 2.5
##
@@ -458,7 +464,8 @@
'max_rd_latency_ns': 'int', 'avg_rd_latency_ns': 'int',
'min_wr_latency_ns': 'int', 'max_wr_latency_ns': 'int',
'avg_wr_latency_ns': 'int', 'min_flush_latency_ns': 'int',
-'max_flush_latency_ns': 'int', 'avg_flush_latency_ns': 'int' } }
+'max_flush_latency_ns': 'int', 'avg_flush_latency_ns': 'int',
+'avg_rd_queue_depth': 'number', 'avg_wr_queue_depth': 'number' } }
##
# @BlockDeviceStats:
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 9f1d2ab..526a317 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -2578,6 +2578,12 @@ Each json-object contain the following:
- "avg_flush_latency_ns": average latency of flush operations
in the defined interval, in
nanoseconds (json-int)
+- "avg_rd_queue_depth": average number of pending read
+operations in the defined interval
+(json-number)
+- "avg_wr_queue_depth": average number of pending write
+operations in the defined interval
+(json-number).
- "parent": Contains recursively the statistics of the underlying
protocol (e.g. the host file for a qcow2 image). If there is
no underlying protocol, this field is omitted
diff --git a/util/timed-average.c b/util/timed-average.c
index 98a1170..70926ef 100644
--- a/util/timed-average.c
+++ b/util/timed-average.c
@@ -208,3 +208,