[LU-12198] lnetctl peer show hangs for ~2600 clients, ioctl getting E2BIG

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0, Lustre 2.12.5
• Affects Version/s: Lustre 2.12.0
• Environment: x86 servers, 2.12 no patches, RHEL 7.6
• Severity: 3
• Assignee: Dominique Martinet (Inactive)
• Reporter: Ruth Klundt (Inactive)

Description

command `lnetctl peer show` appears to hang, strace shows looping on:

ioctl(3, _IOC(_IOC_READ|_IOC_WRITE, 0x65, 0x64, 0xb8), 0x7fffffffccf0) = -1 E2BIG (Argument list too long)

There are 2605 lines in /sys/kernel/debug/lnet/peers.

Issue Links

• is related to: LU-9680 Improve the user land to kernel space interface for lustre