zhenwei pi authored Feb 01, 2024 and Craig Small committed Feb 06, 2024

There are different size of huge pages in a Linux kernel, for example,
modern x86 supports both 2M and 1G huge page size.
According to the latest source code, Linux support as max as 4 hstate:

struct hstate hstates[HUGE_MAX_HSTATE];

The default huge page size could be specified by kernel boot argument
default_hugepagesz. Hugepagesize from /proc/meminfo shows the default
hstate only. Then we hit this issue:
once both 1G and 2M huge pages are in use together,
/proc/meminfo only reports either one. Then part of huge pages are
missing from hugetop, the huge pages number of processes may be wrong.

References:
 #317

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>