Comment # 5 on bug 1187010 from heming zhao

this comment is for updating lvm2 from 2.03.12+ to 2.03.15+

the last/top commit of this update job:

```
From bef1363c0064f42e8063571143a428ad163d1bd9 Mon Sep 17 00:00:00 2001
From: David Teigland <teigland@redhat.com>
Date: Tue, 1 Mar 2022 14:31:39 -0600
Subject: [PATCH 3/3] writecache: check memory usage

warn if writecache neds > 50% of system memory, and
confirm if writecache needs > 90% of system memory.
```

-----------------

test result for lvm2-2.03.15

1> lvm2-testsuite --flavours ndev-vanilla

### 395 tests: 325 passed, 60 skipped, 0 timed out, 3 warned, 7 failed

ndev-vanilla:shell/000-basic.sh warnings           <== same with lvm2-2.03.12
ndev-vanilla:shell/lvconvert-raid.sh warnings      <== same with lvm2-2.03.12
ndev-vanilla:shell/lvcreate-repair.sh warnings     <== same with lvm2-2.03.12

ndev-vanilla:shell/dmeventd-restart.sh failed      <== same with lvm2-2.03.12
ndev-vanilla:shell/integrity-blocksize.sh failed   <== passed after re-test
ndev-vanilla:shell/lvconvert-repair-thin.sh failed <== passed after re-test
ndev-vanilla:shell/lvcreate-usage.sh failed        <== same with lvm2-2.03.12
ndev-vanilla:shell/pvmove-abort-all.sh failed      <== same with lvm2-2.03.12
ndev-vanilla:shell/pvmove-abort.sh failed          <== same with lvm2-2.03.12
ndev-vanilla:shell/read-ahead.sh failed            <== same with lvm2-2.03.12

2> lvm2-testsuite --flavours udev-lvmlockd-test

### 395 tests: 248 passed, 136 skipped, 1 timed out, 3 warned, 7 failed

udev-lvmlockd-test:shell/000-basic.sh warnings            <== same with
lvm2-2.03.12
udev-lvmlockd-test:shell/lvconvert-raid.sh warnings       <== same with
lvm2-2.03.12
udev-lvmlockd-test:shell/lvcreate-repair.sh warnings      <== same with
lvm2-2.03.12

udev-lvmlockd-test:shell/dmeventd-restart.sh failed       <== same with
lvm2-2.03.12
udev-lvmlockd-test:shell/inconsistent-metadata.sh failed  <== testcase wrong
udev-lvmlockd-test:shell/integrity-blocksize.sh failed    <== passed after
re-test
udev-lvmlockd-test:shell/lvconvert-mirror.sh failed       <== passed after
re-test
udev-lvmlockd-test:shell/lvcreate-usage.sh failed         <== same with
lvm2-2.03.12 
udev-lvmlockd-test:shell/pvremove-thin.sh failed          <== same with
lvm2-2.03.12
udev-lvmlockd-test:shell/read-ahead.sh failed             <== same with
lvm2-2.03.12

3> lvm2-testsuite --flavours udev-lvmlockd-dlm

### 392 tests: 249 passed, 131 skipped, 1 timed out, 3 warned, 8 failed

udev-lvmlockd-dlm:shell/000-basic.sh warnings             <== same with
lvm2-2.03.12
udev-lvmlockd-dlm:shell/lvconvert-raid.sh warnings        <== same with
lvm2-2.03.12
udev-lvmlockd-dlm:shell/lvcreate-repair.sh warnings       <== same with
lvm2-2.03.12

udev-lvmlockd-dlm:shell/dmeventd-restart.sh failed        <== same with
lvm2-2.03.12
udev-lvmlockd-dlm:shell/inconsistent-metadata.sh failed   <== testcase wrong
udev-lvmlockd-dlm:shell/integrity-blocksize.sh failed     <== passed after
re-test
udev-lvmlockd-dlm:shell/lvconvert-mirror.sh failed        <== passed after
re-test
udev-lvmlockd-dlm:shell/lvcreate-usage.sh failed          <== same with
lvm2-2.03.12
udev-lvmlockd-dlm:shell/process-each-duplicate-pvs.sh failed <== new case.
testcase wrong
udev-lvmlockd-dlm:shell/read-ahead.sh failed              <== same with
lvm2-2.03.12
udev-lvmlockd-dlm:shell/topology-support.sh failed        <== passed after
re-test


4> Summary

differ with c#2 & c#3. Test result of lvm2-2.03.15 is not worse than 2.03.10+.