[LU-5281] Memory leak when userspace code uses mmap on lustre files

• Status: Resolved
• Project: Lustre
• Affects Version/s: Lustre 2.5.1
• Type: Bug
• Priority: Major
• Reporter: Andrew Prout
• Assignee: WC Triage
• Resolution: Duplicate

Environment

Kernel version: 3.4.93 (also 3.2.58)
Lustre version: 2.5.1 (patchless client)

• Severity: 3

Description

We're seeing kernel a memory leak when a userspace process uses mmap'd files on lustre. It looks like memory is leaked for each unique file that is mmap'd. The code does not need to run as root. The same code on local disk does not cause a leak. The leak will eventually consume all system memory and take the machine down.

To reproduce the bug, compile the below code and run something similar to: find /lustre/ -type f -print0 | xargs -0 -I{} ./mmap_bug "{}"

Kernel version: 3.4.93 (also 3.2.58)
Lustre version: 2.5.1 (patchless client)

#include <sys/types.h>
#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>

int main(int argc, char **argv) {
int f = open(argv[1], O_RDONLY);
void *m = mmap(NULL, 8192, PROT_READ, MAP_SHARED, f, 0);
munmap(m, 8192);
close(f);

return 0;
}

Comments

[Jinshan Xiong (Inactive)]

This should be a reproduction of LU-5179. Please reopen this ticket if the patch can't fix this issue.

[Andrew Prout]

The LU-5179 patch did fix it. I had seen that bug, but we didn't match the conditions described by Oleg (we do not have the jobid functionality enabled).