Redhat升级8.8之后，预留的内存扩大了。
所以依赖于total memory的实现，都需要注意这个变化。
以4G内存的输出为例，前后两个版本的reserved 发生了明显的变化。增加了大约70M的预留内存。
Memory: 2901108K/4193728K available (12293K kernel code, 5878K rwdata, 8376K rodata, 2552K init, 14256K bss, 442992K reserved, 0K cma-reserved)
Memory: 2886708K/4193728K available (14341K kernel code, 5892K rwdata, 8464K rodata, 2596K init, 14140K bss, 510876K reserved, 0K cma-reserved)
通过分析是，做crashkernel的时候预留的更多了。
dmsg:[ 0.000000] Reserving 256MB of memory at 2800MB for crashkernel (System RAM: 8191MB)
dmsg.old:[ 0.000000] Reserving 192MB of memory at 2864MB for crashkernel (System RAM: 8191MB)
https://lore.kernel.org/lkml/YgOGPbdtQIhPNen7@MiWiFi-R3L-srv/T/
ck_cmdline = “1G-4G:192M,4G-64G:256M,64G-:512M”;
ck_cmdline = “1G-4G:160M,4G-64G:192M,64G-1T:256M,1T-:512M”;
- crash_core: Increase crashkernel=auto size for x86_64, s390 and arm64 (Lichen Liu) [2122874]