On 5/27/20 3:05 AM, Alex Bennée wrote:
> +static uintptr_t pgd_find_hole_fallback(uintptr_t guest_size, uintptr_t brk,
> long align)
> +{
> + uintptr_t base;
> +
> + /* Start at the bottom and work our way up */
> + base = mmap_min_addr;
> +
> + while (true) {
> + uintptr_t align_start, end;
> + align_start = ROUND_UP(base, align);
> + end = align_start + guest_size;
> +
> + /* if brk is anywhere in the range give ourselves some room to grow.
> */
> + if (align_start <= brk && brk < end) {
> + base += 16 * MiB;
You should skip the entire brk region with base = brk + 16 * MiB.
> + base += qemu_host_page_size;
If align < qemu_host_page_size, then we'll try the same page multiple times.
Better as base = align_start + qemu_host_page_size.
Or even base = ROUND_UP(base, align) right at the beginning.
r~
