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>
bc00666271