The performance deterioration is observed in the new version

[liuqinfei]

Environment:

`
[root@client1 cachelib]# uname -r
4.18.0-372.9.1.el8.x86_64

[root@client1 cachelib]# cat /etc/os-release
NAME="CentOS Stream"
VERSION="8"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="8"
PLATFORM_ID="platform:el8"
PRETTY_NAME="CentOS Stream 8"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:8"
HOME_URL="https://centos.org/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux 8"
REDHAT_SUPPORT_PRODUCT_VERSION="CentOS Stream"

[root@client1 cachelib]# lscpu |grep CPU
CPU op-mode(s): 32-bit, 64-bit
CPU(s): 96
On-line CPU(s) list: 0-95
CPU family: 6
Model name: Intel(R) Xeon(R) Gold 6248R CPU @ 3.00GHz
BIOS Model name: Intel(R) Xeon(R) Gold 6248R CPU @ 3.00GHz
CPU MHz: 4000.000
CPU max MHz: 4000.0000
CPU min MHz: 1200.0000
NUMA node0 CPU(s): 0-23,48-71
NUMA node1 CPU(s): 24-47,72-95
`

Performance Result

`
Referece version: 953f3c2
Mon Dec 19 15:54:49 2022

[root@client1 cachelib]# ./bin/cachebench --json_test_config test_configs/throughput/same_value_get_throughput_high_contention.json
===JSON Config===
{
"cache_config" : {
"cacheSizeMB" : 20480,
"poolRebalanceIntervalSec" : 0,
"htBucketPower" : 30,
"htLockPower" : 20,
"lruRefreshSec" : 0,
"lruUpdateOnRead" : true,
"tryLockUpdate" : false
},
"test_config" :
{
"samplingIntervalMs" : 60000,

  "numOps" : 10000000,
  "numThreads" : 48,
  "numKeys" : 10000000,


  "keySizeRange" : [8, 9],
  "keySizeRangeProbability" : [1.0],

  "valSizeRange" : [670, 671],
  "valSizeRangeProbability" : [1.0],

  "getRatio" : 1.00,
  "setRatio" : 0.00,
  "delRatio" : 0.00
}

}

Welcome to OSS version of cachebench
Created 9,999,745 keys in 0.03 mins
Generating 480.00M sampled accesses
Generated access patterns in 0.00 mins
Total 480.00M ops to be run
04:26:50 0.00M ops completed. Hit Ratio 0.00%
== Test Results ==
== Allocator Stats ==
Items in RAM : 0
Items in NVM : 0
Alloc Attempts: 0 Success: 0.00%
Evict Attempts: 0 Success: 0.00%
RAM Evictions : 0
Fraction of pool 0 used : 0.00
Cache Gets : 480,000,000
Hit Ratio : 0.00%
NVM Gets : 0, Coalesced : 100.00%
NVM Puts : 0, Success : 0.00%, Clean : 100.00%, AbortsFromDel : 0, AbortsFromGet : 0
NVM Evicts : 0, Clean : 100.00%, Unclean : 0, Double : 0
NVM Deletes : 0 Skipped Deletes: 100.00%

== Throughput for ==
Total Ops : 480.00 million
Total sets: 0
get : 22,163,347/s, success : 0.00%
couldExist: 0/s, success : 0.00%
set : 0/s, success : 0.00%
del : 0/s, found : 0.00%

Version: tag: v2023.08.21.00

[root@client1 cachelib]# ./bin/cachebench --json_test_config test_configs/throughput/same_value_get_throughput_high_contention.json
===JSON Config===
{
"cache_config" : {
"cacheSizeMB" : 20480,
"poolRebalanceIntervalSec" : 0,
"htBucketPower" : 30,
"htLockPower" : 20,
"lruRefreshSec" : 0,
"lruUpdateOnRead" : true,
"tryLockUpdate" : false
},
"test_config" :
{
"samplingIntervalMs" : 60000,

  "numOps" : 10000000,
  "numThreads" : 48,
  "numKeys" : 10000000,


  "keySizeRange" : [8, 9],
  "keySizeRangeProbability" : [1.0],

  "valSizeRange" : [670, 671],
  "valSizeRangeProbability" : [1.0],

  "getRatio" : 1.00,
  "setRatio" : 0.00,
  "delRatio" : 0.00
}

}

Welcome to OSS version of cachebench
Created 9,999,773 keys in 0.23 mins
Generating 480.00M sampled accesses
Generated access patterns in 0.07 mins
Total 480.00M ops to be run
04:12:59 0.00M ops completed. Hit Ratio -1.23% (RAM -1.23%, NVM 0.00%)
== Test Results ==
== Allocator Stats ==
Items in RAM : 0
Items in NVM : 0
Alloc Attempts: 0 Success: 100.00%
Evict Attempts: 0 Success: 0.00%
RAM Evictions : 0
Fraction of pool 0 used : 0.00
Cache Gets : 480,000,000
Hit Ratio : 0.00%
NVM Gets : 0, Coalesced : 0.00%
NVM Puts : 0, Success : 100.00%, Clean : 0.00%, AbortsFromDel : 0, AbortsFromGet : 0
NVM Evicts : 0, Clean : 0.00%, Unclean : 0, Double : 0
NVM Deletes : 0 Skipped Deletes: 0.00%

== Throughput for ==
Total Ops : 480.00 million
Total sets: 0
get : 12,747,930/s, success : 0.00%
couldExist: 0/s, success : 0.00%
set : 0/s, success : 0.00%
del : 0/s, found : 0.00%

`