[LU-16937] lctl allocates IPC shmem segment needlessly

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.16.0
• Affects Version/s: Lustre 2.16.0
• Labels: easy
• Severity: 3
• Assignee: Andreas Dilger
• Reporter: Andreas Dilger

Description

lctl is dynamically allocating an IPC shared memory segment unnecessarily during every startup, even though it is only needed for a small number of uncommon debug commands:

shmget(IPC_PRIVATE, 65680, 0600)        = 196641
shmat(196641, NULL, 0)                  = 0x7f752b1c5000
shmctl(196641, IPC_RMID, NULL)          = 0

The segment is marked for deletion immediately after it is created, so it should be removed automatically when lctl exits, but in some cases this segment appears to stick around and accumulate over time.

This allocation can be moved to the sub-commands that actually need it.