block: latency accounting

Account the total latency for read/write/flush requests.  This allows
management tools to average it based on a snapshot of the nr ops
counters and allow checking for SLAs or provide statistics.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Christoph Hellwig 2011-08-25 08:26:10 +02:00 committed by Kevin Wolf
parent a597e79ce1
commit c488c7f649
4 changed files with 38 additions and 3 deletions

View file

@ -1202,6 +1202,9 @@ Each json-object contain the following:
- "rd_operations": read operations (json-int)
- "wr_operations": write operations (json-int)
- "flush_operations": cache flush operations (json-int)
- "wr_total_time_ns": total time spend on writes in nano-seconds (json-int)
- "rd_total_time_ns": total time spend on reads in nano-seconds (json-int)
- "flush_total_time_ns": total time spend on cache flushes in nano-seconds (json-int)
- "wr_highest_offset": Highest offset of a sector written since the
BlockDriverState has been opened (json-int)
- "parent": Contains recursively the statistics of the underlying
@ -1223,6 +1226,9 @@ Example:
"wr_operations":751,
"rd_bytes":122567168,
"rd_operations":36772
"wr_total_times_ns":313253456
"rd_total_times_ns":3465673657
"flush_total_times_ns":49653
"flush_operations":61,
}
},
@ -1233,6 +1239,9 @@ Example:
"rd_bytes":122739200,
"rd_operations":36604
"flush_operations":51,
"wr_total_times_ns":313253456
"rd_total_times_ns":3465673657
"flush_total_times_ns":49653
}
},
{
@ -1244,6 +1253,9 @@ Example:
"rd_bytes":0,
"rd_operations":0
"flush_operations":0,
"wr_total_times_ns":0
"rd_total_times_ns":0
"flush_total_times_ns":0
}
},
{
@ -1255,6 +1267,9 @@ Example:
"rd_bytes":0,
"rd_operations":0
"flush_operations":0,
"wr_total_times_ns":0
"rd_total_times_ns":0
"flush_total_times_ns":0
}
},
{
@ -1266,6 +1281,9 @@ Example:
"rd_bytes":0,
"rd_operations":0
"flush_operations":0,
"wr_total_times_ns":0
"rd_total_times_ns":0
"flush_total_times_ns":0
}
}
]