Function bt_freehead_toalloc

freebsd/kern/subr_vmem.c:423–440

* bt_freehead_toalloc: return the freelist for the given size and allocation * strategy. * * For M_FIRSTFIT, return the list in which any blocks are large enough * for the requested size. otherwise, return the list which can have blocks * large enough for the requested size. */

 * large enough for the requested size.
 */
static struct vmem_freelist *
bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, int strat)
{
	const vmem_size_t qsize = size >> vm->vm_quantum_shift;
	int idx = SIZE2ORDER(qsize);

	MPASS(size != 0 && qsize != 0);
	MPASS((size & vm->vm_quantum_mask) == 0);

	if (strat == M_FIRSTFIT && ORDER2SIZE(idx) != qsize) {
		idx++;
		/* check too large request? */
	}
	MPASS(idx >= 0);
	MPASS(idx < VMEM_MAXORDER);

	return &vm->vm_freelist[idx];
}

/* ---- boundary tag hash */