static void sanitize_global_limit(unsigned *limit)
{
	/*
	 * The default maximum number of async requests is calculated to consume
	 * 1/2^13 of the total memory, assuming 392 bytes per request.
	 */
	if (*limit == 0)
		*limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392;

	if (*limit >= 1 << 16)
		*limit = (1 << 16) - 1;
}
static void sanitize_global_limit(unsigned *limit)
{
	 
	if (*limit == 0)
		*limit = ((totalram_pages() << PAGE_SHIFT) >> 13) / 392;

	if (*limit >= 1 << 16)
		*limit = (1 << 16) - 1;
}