On Fri, Jul 7, 2023 at 2:41 PM Richard Henderson <
richard.hender...@linaro.org> wrote:
> Use the interval tree to find empty space, rather than
> probing each page in turn.
>
> Cc: Warner Losh <i...@bsdimp.com>
> Cc: Kyle Evans <kev...@freebsd.org>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
>
Reviewed-bt: Warner Losh <i...@bsdimp.com>
I tested the prior version (with a different, but equivalent change) and it
seemed to work where
things had been broken previously.
Warner
> ---
> bsd-user/mmap.c | 48 +++++++-----------------------------------------
> 1 file changed, 7 insertions(+), 41 deletions(-)
>
> diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
> index 07b5b8055e..aca8764356 100644
> --- a/bsd-user/mmap.c
> +++ b/bsd-user/mmap.c
> @@ -222,50 +222,16 @@ unsigned long last_brk;
> static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
> abi_ulong alignment)
> {
> - abi_ulong addr;
> - abi_ulong end_addr;
> - int prot;
> - int looped = 0;
> + abi_ulong ret;
>
> - if (size > reserved_va) {
> - return (abi_ulong)-1;
> + ret = page_find_range_empty(start, reserved_va, size, alignment);
> + if (ret == -1 && start > TARGET_PAGE_SIZE) {
> + /* Restart at the beginning of the address space. */
> + ret = page_find_range_empty(TARGET_PAGE_SIZE, start - 1,
> + size, alignment);
> }
>
> - size = HOST_PAGE_ALIGN(size) + alignment;
> - end_addr = start + size;
> - if (end_addr > reserved_va) {
> - end_addr = reserved_va + 1;
> - }
> - addr = end_addr - qemu_host_page_size;
> -
> - while (1) {
> - if (addr > end_addr) {
> - if (looped) {
> - return (abi_ulong)-1;
> - }
> - end_addr = reserved_va + 1;
> - addr = end_addr - qemu_host_page_size;
> - looped = 1;
> - continue;
> - }
> - prot = page_get_flags(addr);
> - if (prot) {
> - end_addr = addr;
> - }
> - if (end_addr - addr >= size) {
> - break;
> - }
> - addr -= qemu_host_page_size;
> - }
> -
> - if (start == mmap_next_start) {
> - mmap_next_start = addr;
> - }
> - /* addr is sufficiently low to align it up */
> - if (alignment != 0) {
> - addr = (addr + alignment) & ~(alignment - 1);
> - }
> - return addr;
> + return ret;
> }
>
> /*
> --
> 2.34.1
>
>
