1)Check “/sys/kernel/mm/redhat_transparent_hugepage/enabled”.
always - always use THP never - disable THP
if it is set as “always”, then khugepaged will be automatically started.
$ ps -eaf | grep khugepaged root 188 2 0 Feb05 ? 00:04:37 [khugepaged]
2) Check /proc/meminfo.
If THP is enabled :
$ grep AnonHugePages /proc/meminfo AnonHugePages: 8450048 kB
If THP is disabled:
$ grep AnonHugePages /proc/meminfo AnonHugePages: 0 kB
3) for RHEL 6.2 and later, check /proc/vmstat:
If THP is enabled:
$ egrep 'trans|thp' /proc/vmstat nr_anon_transparent_hugepages 4127 thp_fault_alloc 12446176 thp_fault_fallback 7205480 thp_collapse_alloc 27143 thp_collapse_alloc_failed 14815 thp_split 310753 thp_zero_page_alloc 16 thp_zero_page_alloc_failed 0
If THP is disabled:
$ egrep 'trans|thp' /proc/vmstat nr_anon_transparent_hugepages 0 thp_fault_alloc 0 thp_fault_fallback 0 thp_collapse_alloc 0 thp_collapse_alloc_failed 0 thp_split 0 thp_zero_page_alloc 0 thp_zero_page_alloc_failed 0
4) Check THP usage per process:
$ grep -e AnonHugePages /proc/*/smaps | awk '{ if($2>4) print $0} ' | awk -F "/" '{print $0; system("ps -fp " $3)} '
/proc/64068/smaps:AnonHugePages: 2048 kB
UID PID PPID C STIME TTY TIME CMD
oracle 64068 1 0 Feb10 ? 01:50:36 ora_diag_RACNODE1
/proc/64085/smaps:AnonHugePages: 4096 kB
UID PID PPID C STIME TTY TIME CMD
oracle 64085 1 0 Feb10 ? 16:39:31 ora_dia0_RACNODE2
/proc/64085/smaps:AnonHugePages: 6144 kB
...
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