"struct kinfo_proc" lets us query the maximum RSS size ever attained using "i_rusage.ru_maxrss", but there is no similar field for the maximum "ki_size" (size of all virtual memory).
Since both Windows and Linux expect this, linuxulator's sys/compat/linprocfs/linprocfs.c function linprocfs_doprocstatus() completely omits "VmPeak", while in Wine I've had to lie that "ki_size" is both the current and maximum usage.
I wonder whether the kernel even captures that statistic?
Created attachment 229620 [details]
We don't track that value, but it is not hard to add. See the attached patch.
One nit is that we count mappings with protection PROT_NONE, but not guard mappings, but for accounting purposes they should be treated the same. Handling that properly would require some extra complexity that is probably not worth it.
(In reply to Mark Johnston from comment #1)
Mark, may we commit this without reporter feedback? It looks fine to me.
(In reply to Dmitry Chagin from comment #2)
The sys/vm portion of the patch requires some review. I'll post it to phabricator when I get a chance.