Re: qemu-x86_64 runs out of memory

[Richard Henderson]

On 9/13/22 10:35, Andreas Schwab wrote:
> $ cat mmap.c
> #include <stdio.h>
> #include <sys/mman.h>
>
> int
> main (void)
> {
>    void *A;
>    size_t L = 0, U, Max = 0;
>    for (U = 1; ; U *= 2)
>      {
>        A = mmap (0, U, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, 
> -1, 0);
>        if (A == (void *) -1)
>         break;
>        else
>         munmap (A, U);
>      }
>    while (L + 1 < U)
>      {
>        size_t M = L + (U - L) / 2;
>        A = mmap (0, M, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, 
> -1, 0);
>        if (A == (void *) -1)
>         U = M;
>        else
>         {
>           Max = M;
>           munmap(A, M);
>           L = M;
>         }
>      }
>    printf ("%zx\n", Max);
> }
> $ cc -O2 -g -Wall -std=gnu11 -g     mmap.c   -o mmap
> $ ./mmap
> 7f672e5ff000
> $ qemu-x86_64 ./mmap
> Killed

I suspect this is the same as

  https://gitlab.com/qemu-project/qemu/-/issues/290

Needs a reorg of memory region tracking for {linux,bsd}-user.


r~