On 2/3/20 6:31 PM, David Hildenbrand wrote:
> +void *qemu_ram_mmap_resize(void *ptr, int fd, size_t old_size, size_t
> new_size,
> + bool shared, bool is_pmem)
> {
> const size_t pagesize = mmap_pagesize(fd);
>
> /* we can only map whole pages */
> - size = QEMU_ALIGN_UP(size, pagesize);
> + old_size = QEMU_ALIGN_UP(old_size, pagesize);
> + new_size = QEMU_ALIGN_UP(new_size, pagesize);
> +
> + /* we support actually resizable memory regions only on Linux */
> + if (old_size < new_size) {
> + /* populate the missing piece into the reserved area */
> + ptr = mmap_populate(ptr + old_size, new_size - old_size, fd,
> old_size,
> + shared, is_pmem);
> + } else if (old_size > new_size) {
> + /* discard this piece, keeping the area reserved (should never fail)
> */
> + ptr = mmap_reserve(ptr + new_size, old_size - new_size, fd);
> + }
> + return ptr;
> +}
What does the return value indicate?
Is it just for != MAP_FAILED?
Would we be better off with an assert? There's the comment re mmap_reserve,
but I can't see why mmap_populate should fail either.
Assuming an assert isn't viable, are we better off with a boolean return? With
an Error **ptr?
r~
