Acquisition and kernel memory storage of I/O metrics

A computing device, comprising:

• a processor;
• and
• memory, coupled to the processor, the memory constructed and arranged to store instructions executable by the processor,
• wherein the processor executing instructions from the memory forms a specialized circuit constructed and arranged to:
• run a software driver within a kernel of the computing device;
• provide, in the software driver, multiple data buckets for storing information pertaining to a data storage metric, each data bucket covering a different range of values of the metric;
• monitor I/O operations attempted between the computing device and at least one logical storage unit (LUN) to produce multiple values of the metric;
• assign each value of the metric to one of the data buckets for the metric;
• count the number of values of the metric assigned to each data bucket to produce multiple data bucket totals;
• and
• discard the counted values of the metric
• wherein each value of the metric is related to a respective I/O request, and
• wherein the specialized circuit is further constructed and arranged to:
• detect an arrival to the software driver of an I/O request and associating a first timestamp therewith;
• detect a passage of the I/O request from the software driver and recording a second timestamp associated therewith;
• detect a return to the software driver of a returning I/O response and associating a third timestamp therewith;
• and
• computing a latency value based on any two of the first through third timestamps.

A non-transitory computer readable medium including instructions which, when executed by a processor of a computing device, cause the processor to perform a method for obtaining performance information relating to data storage, the method comprising:

• providing, in a software driver within a kernel of the computing device, multiple data buckets for storing information pertaining to a data storage metric, each data bucket covering a different range of values of the metric;
• monitoring I/O operations attempted between the computing device and at least one logical storage unit (LUN) to produce multiple values of the metric;
• assigning each value of the metric to one of the data buckets for the metric;
• counting the number of values of the metric assigned to each data bucket to produce multiple data bucket totals;
• and
• discarding the counted values of the metric,
• wherein each value of the metric is related to a respective I/O request and wherein monitoring I/O operations attempted between the computing device and at least one logical storage unit to produce multiple values of the metric includes, for at least one of the multiple values:
• detecting an arrival to the software driver of an I/O request and associating a first timestamp therewith;
• detecting a passage of the I/O request from the software driver and recording a second timestamp associated therewith;
• detecting a return to the software driver of a returning I/O response and associating a third timestamp therewith;
• and
• computing a latency value based on any two of the first through third timestamps.

A method operable on a computing device for obtaining performance information relating to data storage, comprising:

• providing, in a software driver running within a kernel of the computing device, multiple data buckets for storing information pertaining to a metric relating to data storage, each data bucket covering a different range of values of the metric;
• monitoring I/O operations attempted between the computing device and at least one logical storage unit (LUN) to produce multiple values of the metric;
• assigning each value of the metric to one of the data buckets for the metric;
• summing the values of the metric assigned to each data bucket to produce multiple data bucket sums;
• and
• discarding the values of the metric,
• wherein monitoring I/O operations includes, for at least one of the multiple values:
• detecting an arrival to the software driver of an I/O request and associating a first timestamp therewith;
• detecting a passage of the I/O request from the software driver and recording a second timestamp associated therewith;
• detecting a return to the software driver of a returning I/O response and associating a third timestamp therewith;
• and
• computing a latency value based on any two of the first through third timestamps.