diff options
Diffstat (limited to 'Documentation/admin-guide/iostats.rst')
| -rw-r--r-- | Documentation/admin-guide/iostats.rst | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/Documentation/admin-guide/iostats.rst b/Documentation/admin-guide/iostats.rst index df5b8345c41d..609a3201fd4e 100644 --- a/Documentation/admin-guide/iostats.rst +++ b/Documentation/admin-guide/iostats.rst @@ -76,7 +76,7 @@ Field 3 -- # of sectors read (unsigned long) Field 4 -- # of milliseconds spent reading (unsigned int) This is the total number of milliseconds spent by all reads (as - measured from __make_request() to end_that_request_last()). + measured from blk_mq_alloc_request() to __blk_mq_end_request()). Field 5 -- # of writes completed (unsigned long) This is the total number of writes completed successfully. @@ -89,7 +89,7 @@ Field 7 -- # of sectors written (unsigned long) Field 8 -- # of milliseconds spent writing (unsigned int) This is the total number of milliseconds spent by all writes (as - measured from __make_request() to end_that_request_last()). + measured from blk_mq_alloc_request() to __blk_mq_end_request()). Field 9 -- # of I/Os currently in progress (unsigned int) The only field that should go to zero. Incremented as requests are @@ -100,7 +100,7 @@ Field 10 -- # of milliseconds spent doing I/Os (unsigned int) Since 5.0 this field counts jiffies when at least one request was started or completed. If request runs more than 2 jiffies then some - I/O time will not be accounted unless there are other requests. + I/O time might be not accounted in case of concurrent requests. Field 11 -- weighted # of milliseconds spent doing I/Os (unsigned int) This field is incremented at each I/O start, I/O completion, I/O @@ -120,7 +120,7 @@ Field 14 -- # of sectors discarded (unsigned long) Field 15 -- # of milliseconds spent discarding (unsigned int) This is the total number of milliseconds spent by all discards (as - measured from __make_request() to end_that_request_last()). + measured from blk_mq_alloc_request() to __blk_mq_end_request()). Field 16 -- # of flush requests completed This is the total number of flush requests completed successfully. @@ -143,6 +143,9 @@ are summed (possibly overflowing the unsigned long variable they are summed to) and the result given to the user. There is no convenient user interface for accessing the per-CPU counters themselves. +Since 4.19 request times are measured with nanoseconds precision and +truncated to milliseconds before showing in this interface. + Disks vs Partitions ------------------- |