I want to limit a per user memory usage for every running jail.
I'm tried to set a limits like this:
jail:pg198:vmemoryuse:deny=17179869184/user
jail:pg199:vmemoryuse:deny=17179869184/user

I have users with same uid in there jails, resulting a memory allocation for user in jail pg198, makes impossible to use this limit for same user in jail pg199.

To check I used this simple code:
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>

int
main(int argc, char *argv[]) {
        long size = atol(argv[1]);
        void *buf = malloc(size);

        if (buf == NULL) {
                fprintf(stderr, "malloc(%li) failed: %s\n", size, strerror(errno));
                return 1;
        }

        fgets(buf, size < 1024 ? size : 1024, stdin);
        return 0;
}

And when a user in one jail is running a command:
./alloc $((10*1024*1024*1024))
User in a different jail can't allocate memory:
malloc(10737418240) failed: Cannot allocate memory

A limits like jail:jailname:vmemoryuse:deny=limit/user should limit a allocated memory per user for each jail, but not for user in all jails.