Comment 11 for bug 1912652

Verified glibc 2.31-0ubuntu9.3 on Focal.

root@ff-lp1912652:~# gcc -O2 -o a.out a.c -lpthread -DITER=1000 -DTHREADS=64
root@ff-lp1912652:~# time ./a.out
thread 0: min=128, max=390014464, average=15175.931641, mutexes_locked=224170, flips=12
...
thread 63: min=128, max=212314560, average=31851.539062, mutexes_locked=105648, flips=1
server: min=128, max=249241888, average=581391.875000, mutexes_locked=6158, flips=1000

real 0m0.938s
user 0m7.363s
sys 0m0.064s
root@ff-lp1912652:~# apt install libc6-lse
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  libc6-lse
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 1035 kB of archives.
After this operation, 3244 kB of additional disk space will be used.
Get:1 http://ports.ubuntu.com/ubuntu-ports focal-updates/main arm64 libc6-lse arm64 2.31-0ubuntu9.2 [1035 kB]
Fetched 1035 kB in 1s (1393 kB/s)
Selecting previously unselected package libc6-lse:arm64.
(Reading database ... 35769 files and directories currently installed.)
Preparing to unpack .../libc6-lse_2.31-0ubuntu9.2_arm64.deb ...
Unpacking libc6-lse:arm64 (2.31-0ubuntu9.2) ...
Setting up libc6-lse:arm64 (2.31-0ubuntu9.2) ...
Processing triggers for libc-bin (2.31-0ubuntu9.2) ...
root@ff-lp1912652:~# reboot

Session terminated, killing shell... ...killed.
ubuntu@ip-172-31-20-158:~$ lxc shell ff-lp1912652
root@ff-lp1912652:~# time ./a.out
thread 0: min=128, max=1119296, average=20925.992188, mutexes_locked=1371, flips=36
...thread 61: min=128, max=15716704, average=295146.343750, mutexes_locked=96, flips=0
thread 62: min=1000000, max=12458848, average=12458848.000000, mutexes_locked=1, flips=0
thread 63: min=128, max=9601760, average=27332.921875, mutexes_locked=1255, flips=9
server: min=128, max=5040224, average=19802.298828, mutexes_locked=1437, flips=1000

real 0m0.014s
user 0m0.023s
sys 0m0.059s
root@ff-lp1912652:~# apt install libc-bin libc-dev-bin libc6 libc6-dev locales
Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
  glibc-doc
The following packages will be REMOVED:
  libc6-lse
The following packages will be upgraded:
  libc-bin libc-dev-bin libc6 libc6-dev locales
5 upgraded, 0 newly installed, 1 to remove and 12 not upgraded.
Need to get 8770 kB of archives.
After this operation, 3159 kB disk space will be freed.
Do you want to continue? [Y/n]
Get:1 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 libc6-dev arm64 2.31-0ubuntu9.3 [2068 kB]
Get:2 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 libc-dev-bin arm64 2.31-0ubuntu9.3 [64.2 kB]
Get:3 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 libc6 arm64 2.31-0ubuntu9.3 [2270 kB]
Get:4 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 locales all 2.31-0ubuntu9.3 [3862 kB]
Get:5 http://ports.ubuntu.com/ubuntu-ports focal-proposed/main arm64 libc-bin arm64 2.31-0ubuntu9.3 [506 kB]
Fetched 8770 kB in 1s (7065 kB/s)
Preconfiguring packages ...
(Reading database ... 35813 files and directories currently installed.)
Removing libc6-lse:arm64 (2.31-0ubuntu9.2) ...
(Reading database ... 35769 files and directories currently installed.)
Preparing to unpack .../libc6-dev_2.31-0ubuntu9.3_arm64.deb ...
Unpacking libc6-dev:arm64 (2.31-0ubuntu9.3) over (2.31-0ubuntu9.2) ...
Preparing to unpack .../libc-dev-bin_2.31-0ubuntu9.3_arm64.deb ...
Unpacking libc-dev-bin (2.31-0ubuntu9.3) over (2.31-0ubuntu9.2) ...
Preparing to unpack .../libc6_2.31-0ubuntu9.3_arm64.deb ...
Unpacking libc6:arm64 (2.31-0ubuntu9.3) over (2.31-0ubuntu9.2) ...
Setting up libc6:arm64 (2.31-0ubuntu9.3) ...
(Reading database ... 35769 files and directories currently installed.)
Preparing to unpack .../locales_2.31-0ubuntu9.3_all.deb ...
Unpacking locales (2.31-0ubuntu9.3) over (2.31-0ubuntu9.2) ...
Preparing to unpack .../libc-bin_2.31-0ubuntu9.3_arm64.deb ...
Unpacking libc-bin (2.31-0ubuntu9.3) over (2.31-0ubuntu9.2) ...
Setting up libc-bin (2.31-0ubuntu9.3) ...
Setting up locales (2.31-0ubuntu9.3) ...
Generating locales (this might take a while)...
  en_US.UTF-8... done
Generation complete.
Setting up libc-dev-bin (2.31-0ubuntu9.3) ...
Setting up libc6-dev:arm64 (2.31-0ubuntu9.3) ...
Processing triggers for man-db (2.9.1-1) ...
root@ff-lp1912652:~# time ./a.out
thread 0: min=128, max=2640064, average=19436.712891, mutexes_locked=1334, flips=31
thread 1: min=128, max=2480992, average=13251.751953, mutexes_locked=2115, flips=53
...

thread 62: min=128, max=112618720, average=94604.898438, mutexes_locked=2004, flips=25
thread 63: min=128, max=129409344, average=88098.539062, mutexes_locked=3266, flips=14
server: min=128, max=94762112, average=140166.890625, mutexes_locked=1347, flips=1000

real 0m0.080s
user 0m0.181s
sys 0m0.441s
root@ff-lp1912652:~# dpkg -l libc6
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name Version Architecture Description
+++-==============-===============-============-=================================
ii libc6:arm64 2.31-0ubuntu9.3 arm64 GNU C Library: Shared libraries
root@ff-lp1912652:~#