Stop using a soft-interrupt context to process incoming network packets.

Use a new task that runs holding the KERNEL_LOCK to execute mp-unsafe
code.  Our current goal is to progressively move input functions to the
unlocked task.

This gives a small performance boost confirmed by Hrvoje Popovski's
IPv4 forwarding measurement:

before:					after:

send           receive			send           receive
400kpps        400kpps                  400kpps        400kpps
500kpps        500kpps                  500kpps        500kpps
600kpps        600kpps                  600kpps        600kpps
650kpps        650kpps                  650kpps        640kpps
700kpps        700kpps                  700kpps        700kpps
720kpps        640kpps                  720kpps        710kpps
800kpps        640kpps                  800kpps        650kpps
1.4Mpps        570kpps                  1.4Mpps        590kpps
14Mpps         570kpps                  14Mpps         590kpps


ok kettenis@, bluhm@, dlg@

5 files changed, 65 insertions, 94 deletions

diff --git a/sys/conf/files b/sys/conf/files
index d22604bc13b..a061c7f0a0e 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1,4 +1,4 @@
-#	$OpenBSD: files,v 1.618 2016/04/25 20:09:14 tedu Exp $
+#	$OpenBSD: files,v 1.619 2016/05/03 14:52:39 mpi Exp $
 #	$NetBSD: files,v 1.87 1996/05/19 17:17:50 jonathan Exp $
 
 #	@(#)files.newconf	7.5 (Berkeley) 5/10/93
@@ -763,7 +763,6 @@ file net/if_spppsubr.c			sppp
 file net/if_loop.c			loop
 file net/if_media.c			ifmedia
 file net/if_ppp.c			ppp			needs-count
-file net/netisr.c
 file net/ppp_tty.c			ppp
 file net/bsd-comp.c			ppp_bsdcomp
 file net/ppp-deflate.c			ppp_deflate
diff --git a/sys/kern/init_main.c b/sys/kern/init_main.c
index 312bd87e1ea..61110b51abb 100644
--- a/sys/kern/init_main.c
+++ b/sys/kern/init_main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: init_main.c,v 1.249 2016/03/19 12:04:15 natano Exp $	*/
+/*	$OpenBSD: init_main.c,v 1.250 2016/05/03 14:52:39 mpi Exp $	*/
 /*	$NetBSD: init_main.c,v 1.84.4.1 1996/06/02 09:08:06 mrg Exp $	*/
 
 /*
@@ -394,7 +394,6 @@ main(void *framep)
 	 * until everything is ready.
 	 */
 	s = splnet();
-	netisr_init();
 	domaininit();
 	splx(s);
 
diff --git a/sys/net/if.c b/sys/net/if.c
index fbe239d38a0..55cbda3382e 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if.c,v 1.429 2016/03/16 12:08:09 dlg Exp $	*/
+/*	$OpenBSD: if.c,v 1.430 2016/05/03 14:52:39 mpi Exp $	*/
 /*	$NetBSD: if.c,v 1.35 1996/05/07 05:26:04 thorpej Exp $	*/
 
 /*
@@ -64,9 +64,12 @@
 #include "bpfilter.h"
 #include "bridge.h"
 #include "carp.h"
+#include "ether.h"
 #include "pf.h"
+#include "pfsync.h"
+#include "ppp.h"
+#include "pppoe.h"
 #include "trunk.h"
-#include "ether.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -148,6 +151,7 @@ int	if_group_egress_build(void);
 void	if_watchdog_task(void *);
 
 void	if_input_process(void *);
+void	if_netisr(void *);
 
 #ifdef DDB
 void	ifa_print_all(void);
@@ -216,13 +220,15 @@ void	net_tick(void *);
 int	net_livelocked(void);
 int	ifq_congestion;
 
-struct taskq *softnettq;
+int		 netisr;
+struct taskq	*softnettq;
+
+struct mbuf_queue if_input_queue = MBUF_QUEUE_INITIALIZER(8192, IPL_NET);
+struct task if_input_task = TASK_INITIALIZER(if_input_process, &if_input_queue);
+struct task if_input_task_locked = TASK_INITIALIZER(if_netisr, NULL);
 
 /*
  * Network interface utility routines.
- *
- * Routines with ifa_ifwith* names take sockaddr *'s as
- * parameters.
  */
 void
 ifinit(void)
@@ -590,9 +596,6 @@ if_enqueue(struct ifnet *ifp, struct mbuf *m)
 	return (0);
 }
 
-struct mbuf_queue if_input_queue = MBUF_QUEUE_INITIALIZER(8192, IPL_NET);
-struct task if_input_task = TASK_INITIALIZER(if_input_process, &if_input_queue);
-
 void
 if_input(struct ifnet *ifp, struct mbuf_list *ml)
 {
@@ -806,6 +809,50 @@ if_input_process(void *xmq)
 }
 
 void
+if_netisr(void *unused)
+{
+	int n, t = 0;
+	int s;
+
+	KERNEL_LOCK();
+	s = splsoftnet();
+
+	while ((n = netisr) != 0) {
+		sched_pause();
+
+		atomic_clearbits_int(&netisr, n);
+
+		if (n & (1 << NETISR_IP))
+			ipintr();
+#ifdef INET6
+		if (n & (1 << NETISR_IPV6))
+			ip6intr();
+#endif
+#if NPPP > 0
+		if (n & (1 << NETISR_PPP))
+			pppintr();
+#endif
+#if NBRIDGE > 0
+		if (n & (1 << NETISR_BRIDGE))
+			bridgeintr();
+#endif
+#if NPPPOE > 0
+		if (n & (1 << NETISR_PPPOE))
+			pppoeintr();
+#endif
+		t |= n;
+	}
+
+#if NPFSYNC > 0
+	if (t & (1 << NETISR_PFSYNC))
+		pfsyncintr();
+#endif
+
+	splx(s);
+	KERNEL_UNLOCK();
+}
+
+void
 if_deactivate(struct ifnet *ifp)
 {
 	int s;
diff --git a/sys/net/netisr.c b/sys/net/netisr.c
deleted file mode 100644
index 7b6475be1b8..00000000000
--- a/sys/net/netisr.c
+++ /dev/null
@@ -1,74 +0,0 @@
-/*
- * Copyright (c) 2010 Owain G. Ainsworth <oga@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-#include <sys/param.h>
-#include <sys/systm.h>
-
-#include <net/netisr.h>
-
-#include <machine/intr.h>
-
-#include "ppp.h"
-#include "bridge.h"
-#include "pppoe.h"
-#include "pfsync.h"
-
-void	 netintr(void *);
-
-int	 netisr;
-void	*netisr_intr;
-
-void
-netintr(void *unused)
-{
-	int n, t = 0;
-
-	while ((n = netisr) != 0) {
-		atomic_clearbits_int(&netisr, n);
-
-		if (n & (1 << NETISR_IP))
-			ipintr();
-#ifdef INET6
-		if (n & (1 << NETISR_IPV6))
-			ip6intr();
-#endif
-#if NPPP > 0
-		if (n & (1 << NETISR_PPP))
-			pppintr();
-#endif
-#if NBRIDGE > 0
-		if (n & (1 << NETISR_BRIDGE))
-			bridgeintr();
-#endif
-#if NPPPOE > 0
-		if (n & (1 << NETISR_PPPOE))
-			pppoeintr();
-#endif
-		t |= n;
-	}
-
-#if NPFSYNC > 0
-	if (t & (1 << NETISR_PFSYNC))
-		pfsyncintr();
-#endif
-}
-
-void
-netisr_init(void)
-{
-	netisr_intr = softintr_establish(IPL_SOFTNET, netintr, NULL);
-	if (netisr_intr == NULL)
-		panic("can't establish softnet handler");
-}
diff --git a/sys/net/netisr.h b/sys/net/netisr.h
index 482c7c8ce00..5c709f5b76d 100644
--- a/sys/net/netisr.h
+++ b/sys/net/netisr.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: netisr.h,v 1.44 2016/01/08 13:53:24 mpi Exp $	*/
+/*	$OpenBSD: netisr.h,v 1.45 2016/05/03 14:52:39 mpi Exp $	*/
 /*	$NetBSD: netisr.h,v 1.12 1995/08/12 23:59:24 mycroft Exp $	*/
 
 /*
@@ -61,7 +61,12 @@
 
 #ifndef _LOCORE
 #ifdef _KERNEL
+
+#include <sys/task.h>
+#include <sys/atomic.h>
+
 extern int	netisr;			/* scheduling bits for network */
+extern struct task if_input_task_locked;
 
 void	ipintr(void);
 void	ip6intr(void);
@@ -70,17 +75,12 @@ void	bridgeintr(void);
 void	pppoeintr(void);
 void	pfsyncintr(void);
 
-#include <machine/atomic.h>
-
-extern void *netisr_intr;
 #define	schednetisr(anisr)						\
 do {									\
 	atomic_setbits_int(&netisr, (1 << (anisr)));			\
-	softintr_schedule(netisr_intr);					\
+	task_add(softnettq, &if_input_task_locked);			\
 } while (/* CONSTCOND */0)
 
-void	netisr_init(void);
-
 #endif /* _KERNEL */
 #endif /*_LOCORE */