Instead of creating a purge thread for every vnet, create

a single purge thread and clean up all vnets from this thread.

PR:                     194515
Differential Revision:  D1315
Submitted by:           Nikos Vassiliadis <[email protected]>

sys/netpfil/pf/pf.c

@@ -1384,71 +1384,37 @@ pf_intr(void *v)
 }
 
 void
-pf_purge_thread(void *v)
+pf_purge_thread(void *v __unused)
 {
 	u_int idx = 0;
-
-	CURVNET_SET((struct vnet *)v);
+	VNET_ITERATOR_DECL(vnet_iter);
 
 	for (;;) {
-		PF_RULES_RLOCK();
-		rw_sleep(pf_purge_thread, &pf_rules_lock, 0, "pftm", hz / 10);
-
-		if (V_pf_end_threads) {
-			/*
-			 * To cleanse up all kifs and rules we need
-			 * two runs: first one clears reference flags,
-			 * then pf_purge_expired_states() doesn't
-			 * raise them, and then second run frees.
-			 */
-			PF_RULES_RUNLOCK();
-			pf_purge_unlinked_rules();
-			pfi_kif_purge();
-
-			/*
-			 * Now purge everything.
-			 */
-			pf_purge_expired_states(0, pf_hashmask);
-			pf_purge_expired_fragments();
-			pf_purge_expired_src_nodes();
-
-			/*
-			 * Now all kifs & rules should be unreferenced,
-			 * thus should be successfully freed.
-			 */
-			pf_purge_unlinked_rules();
-			pfi_kif_purge();
-
-			/*
-			 * Announce success and exit.
-			 */
-			PF_RULES_RLOCK();
-			V_pf_end_threads++;
-			PF_RULES_RUNLOCK();
-			wakeup(pf_purge_thread);
-			kproc_exit(0);
-		}
-		PF_RULES_RUNLOCK();
-
-		/* Process 1/interval fraction of the state table every run. */
-		idx = pf_purge_expired_states(idx, pf_hashmask /
-			    (V_pf_default_rule.timeout[PFTM_INTERVAL] * 10));
-
-		/* Purge other expired types every PFTM_INTERVAL seconds. */
-		if (idx == 0) {
-			/*
-			 * Order is important:
-			 * - states and src nodes reference rules
-			 * - states and rules reference kifs
-			 */
-			pf_purge_expired_fragments();
-			pf_purge_expired_src_nodes();
-			pf_purge_unlinked_rules();
-			pfi_kif_purge();
+		tsleep(pf_purge_thread, PWAIT, "pftm", hz / 10);
+		VNET_LIST_RLOCK();
+		VNET_FOREACH(vnet_iter) {
+			CURVNET_SET(vnet_iter);
+			/* Process 1/interval fraction of the state table every run. */
+			idx = pf_purge_expired_states(idx, pf_hashmask /
+				    (V_pf_default_rule.timeout[PFTM_INTERVAL] * 10));
+
+			/* Purge other expired types every PFTM_INTERVAL seconds. */
+			if (idx == 0) {
+				/*
+				 * Order is important:
+				 * - states and src nodes reference rules
+				 * - states and rules reference kifs
+				 */
+				pf_purge_expired_fragments();
+				pf_purge_expired_src_nodes();
+				pf_purge_unlinked_rules();
+				pfi_kif_purge();
+			}
+			CURVNET_RESTORE();
 		}
+		VNET_LIST_RUNLOCK();
 	}
 	/* not reached */
-	CURVNET_RESTORE();
 }
 
 u_int32_t