1PART_ROUND_STATS(9)              Block Devices             PART_ROUND_STATS(9)
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NAME

6       part_round_stats - Round off the performance stats on a struct
7       disk_stats.
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SYNOPSIS

10       void part_round_stats(struct request_queue * q, int cpu,
11                             struct hd_struct * part);
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ARGUMENTS

14       q
15           target block queue
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17       cpu
18           cpu number for stats access
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20       part
21           target partition
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DESCRIPTION

24       The average IO queue length and utilisation statistics are maintained
25       by observing the current state of the queue length and the amount of
26       time it has been in this state for.
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28       Normally, that accounting is done on IO completion, but that can result
29       in more than a second's worth of IO being accounted for within any one
30       second, leading to >100% utilisation. To deal with that, we call this
31       function to do a round-off before returning the results when reading
32       /proc/diskstats. This accounts immediately for all queue usage up to
33       the current jiffies and restarts the counters again.
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36Kernel Hackers Manual 3.10         June 2019               PART_ROUND_STATS(9)
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