Comment 3 for bug 1996595

The kernel stack trace shows that this occurs when mmap populates the pages, that is, when the mmap'd range is requested to be backed by physical memory. This OOM is not occurring when the mlock is being called. This behavior is expected, pages are mmap'd and locked by many of the stressor instances leaving little physical memory left. Some stressors get unlucky, their mmap request don't have physical memory for the mmap + populate causing an OOM.