Commit Graph

2 Commits

Author SHA1 Message Date
Jim Harris
bc00666271 util: enable dynamic spdk_histogram_data sizing
Currently, each histogram range is hardcoded to
128 buckets (1ULL << 7), resulting in 58 ranges
(64 - 7 + 1) and a total size of 58 * 128 *
sizeof(uint64_t) = 59392 bytes.

To allow for more usage models in cases where this
size is prohibitive, enable the following changes:

1) specify number of buckets per range (in number of bits)
2) specify max datapoint value (in number of bits)

The latter can be useful for cases where datapoints
are never close to requiring all 64 bits - and allows
reducing the number of ranges.  Any data points that
exceed the max will be tallied in the last bucket
in the last range.

Testing shows no performance disadvantage using the
dynamic approach.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I5979bcdff6209faaa9dee293918ef2a78679bcd4

Reviewed-on: https://review.gerrithub.io/392707
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
2017-12-29 14:20:48 -05:00
Jim Harris
ea17499c6c test: add util/histogram_perf test application
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I050ecd4f3bbccbd527387d080ce595fae16479d3

Reviewed-on: https://review.gerrithub.io/392704
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
2017-12-29 14:20:48 -05:00