Function vm_daemon

freebsd/vm/vm_swapout.c:367–522

}

static void
vm_daemon(void)
{
	struct rlimit rsslim;
	struct proc *p;
	struct thread *td;
	struct vmspace *vm;
	int breakout, swapout_flags, tryagain, attempts;
#ifdef RACCT
	uint64_t rsize, ravailable;
#endif

	while (TRUE) {
		mtx_lock(&vm_daemon_mtx);
		msleep(&vm_daemon_needed, &vm_daemon_mtx, PPAUSE, "psleep",
#ifdef RACCT
		    racct_enable ? hz : 0
#else
		    0
#endif
		);
		swapout_flags = vm_pageout_req_swapout;
		vm_pageout_req_swapout = 0;
		mtx_unlock(&vm_daemon_mtx);
		if (swapout_flags != 0) {
			/*
			 * Drain the per-CPU page queue batches as a deadlock
			 * avoidance measure.
			 */
			if ((swapout_flags & VM_SWAP_NORMAL) != 0)
				vm_page_pqbatch_drain();
			swapout_procs(swapout_flags);
		}

		/*
		 * scan the processes for exceeding their rlimits or if
		 * process is swapped out -- deactivate pages
		 */
		tryagain = 0;
		attempts = 0;
again:
		attempts++;
		sx_slock(&allproc_lock);
		FOREACH_PROC_IN_SYSTEM(p) {
			vm_pindex_t limit, size;

			/*
			 * if this is a system process or if we have already
			 * looked at this process, skip it.
			 */
			PROC_LOCK(p);
			if (p->p_state != PRS_NORMAL ||
			    p->p_flag & (P_INEXEC | P_SYSTEM | P_WEXIT)) {
				PROC_UNLOCK(p);
				continue;
			}
			/*
			 * if the process is in a non-running type state,