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part_round_stats(9) [centos man page]

PART_ROUND_STATS(9)						   Block Devices					       PART_ROUND_STATS(9)

part_round_stats - Round off the performance stats on a struct disk_stats. SYNOPSIS
void part_round_stats(int cpu, struct hd_struct * part); ARGUMENTS
cpu cpu number for stats access part target partition DESCRIPTION
The average IO queue length and utilisation statistics are maintained by observing the current state of the queue length and the amount of time it has been in this state for. Normally, that accounting is done on IO completion, but that can result in more than a second's worth of IO being accounted for within any one second, leading to >100% utilisation. To deal with that, we call this function to do a round-off before returning the results when reading /proc/diskstats. This accounts immediately for all queue usage up to the current jiffies and restarts the counters again. COPYRIGHT
Kernel Hackers Manual 3.10 June 2014 PART_ROUND_STATS(9)

Check Out this Related Man Page

sa(8)							      System Manager's Manual							     sa(8)

       sa, accton - print process accounting statistics

       /etc/sa [ options ] [ file ]

       /etc/accton [ file ]

       file    With  an  argument naming an existing file, causes system accounting information for every process executed to be placed at the end
	       of the file.  If no argument is given, accounting is turned off.

       The command reports on, cleans up, and generally maintains accounting files.

       The is able to condense the information in into a summary file which contains a count of the number of times each command  was  called  and
       the time resources consumed.  This condensation is desirable because on a large system can grow by 100 blocks per day.  The summary file is
       normally read before the accounting file, so the reports include all available information.

       If a file name is given as the last argument, that file will be treated as the accounting file.	The file is the default.

       Output fields are labeled: "cpu" for the sum of user+system time (in cpu seconds), "re" for real time (also in cpu seconds), "k"  for  cpu-
       time  averaged  core usage (in 1k units), "avio" for average number of I/O operations per execution.  With options fields labeled "tio" for
       total I/O operations, "k*sec" for cpu storage integral (kilo-core seconds), "u" and "s" for user and system cpu time  alone  (both  in  cpu
       seconds) will sometimes appear.

       -a      List  all  command names including those containing unprintable characters and those used only once. By default, places all command
	       names containing unprintable characters and those used only once under the name `***other.'

       -b      Sort output by sum of user and system time divided by number of calls.  Default sort is by sum of user and system times.

       -c      Besides total user, system, and real time for each command, print percentage of total time over all commands.

       -d      Sort by average number of disk I/O operations.

       -D      Print and sort by total number of disk I/O operations.

       -f      Force no interactive threshold compression with option.

       -i      Do not read in summary file.

       -j      Instead of total minutes for each category, give seconds per call.

       -k      Sort by cpu-time average memory usage.

       -K      Print and sort by cpu-storage integral.

       -l      Separate system and user time; normally they are combined.

       -m      Print number of processes and number of CPU minutes for each user.

       -n      Sort by number of calls.

       -r      Reverse order of sort.

       -s      Merge accounting file into summary file when done.

       -t      For each command, report ratio of real time to the sum of user and system times.  If the sum of user and system times is too  small
	       to report, `*ignore*' appears in this field.

       -u      Superseding all other flags, print for each command in the accounting file the user ID and command name.

       -v      Followed  by  a number n, types the name of each command used n times or fewer.	Await a reply from the terminal; if it begins with
	       `y', add the command to the category `**junk**.' This is used to strip out garbage.

       Accounting is suspended when there is less than 2% free space on disk.  Accounting resumes when free space rises above 4%.

       Raw accounting


       Per-user summary

See Also
       acct(2), ac(8)

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