Module Name: src
Committed By: ozaki-r
Date: Fri Dec 8 05:22:23 UTC 2017
Modified Files:
src/sys/dev/pci: if_wm.c
src/sys/net: if.c if.h
Log Message:
Revert "Make if_timer MP-safe if IFEF_MPSAFE"
Because it has decreased the performance of wm. And also I found that
wm_watchdog doesn't work well with if_watchdog framework at all. Sharing one
counter (if_timer) with multiple instances (hardware multi-queues) can't detect
a single (or some) stall of them because other instances reset the counter even
if the stalled one want the watchdog to fire.
Interfaces without IFEF_MPSAFE works safely with the original if_watchdog thanks
to KENREL_LOCK. OTOH, interfaces with IFEF_MPSAFE shouldn't use if_watchdog and
should implement their own watchdog timer that works with multiple instances.
To generate a diff of this commit:
cvs rdiff -u -r1.548 -r1.549 src/sys/dev/pci/if_wm.c
cvs rdiff -u -r1.410 -r1.411 src/sys/net/if.c
cvs rdiff -u -r1.250 -r1.251 src/sys/net/if.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/pci/if_wm.c
diff -u src/sys/dev/pci/if_wm.c:1.548 src/sys/dev/pci/if_wm.c:1.549
--- src/sys/dev/pci/if_wm.c:1.548 Thu Dec 7 00:38:38 2017
+++ src/sys/dev/pci/if_wm.c Fri Dec 8 05:22:23 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: if_wm.c,v 1.548 2017/12/07 00:38:38 msaitoh Exp $ */
+/* $NetBSD: if_wm.c,v 1.549 2017/12/08 05:22:23 ozaki-r Exp $ */
/*
* Copyright (c) 2001, 2002, 2003, 2004 Wasabi Systems, Inc.
@@ -83,7 +83,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.548 2017/12/07 00:38:38 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wm.c,v 1.549 2017/12/08 05:22:23 ozaki-r Exp $");
#ifdef _KERNEL_OPT
#include "opt_net_mpsafe.h"
@@ -5937,7 +5937,7 @@ wm_stop_locked(struct ifnet *ifp, int di
/* Mark the interface as down and cancel the watchdog timer. */
ifp->if_flags &= ~(IFF_RUNNING | IFF_OACTIVE);
- if_watchdog_stop(ifp);
+ ifp->if_timer = 0;
if (disable) {
for (i = 0; i < sc->sc_nqueues; i++) {
@@ -7373,7 +7373,7 @@ wm_send_common_locked(struct ifnet *ifp,
if (txq->txq_free != ofree) {
/* Set a watchdog timer in case the chip flakes out. */
- if_watchdog_reset(ifp, 5);
+ ifp->if_timer = 5;
}
}
@@ -7945,7 +7945,7 @@ wm_nq_send_common_locked(struct ifnet *i
if (sent) {
/* Set a watchdog timer in case the chip flakes out. */
- if_watchdog_reset(ifp, 5);
+ ifp->if_timer = 5;
}
}
@@ -8082,7 +8082,7 @@ wm_txeof(struct wm_softc *sc, struct wm_
* timer.
*/
if (txq->txq_sfree == WM_TXQUEUELEN(txq))
- if_watchdog_stop(ifp);
+ ifp->if_timer = 0;
return processed;
}
Index: src/sys/net/if.c
diff -u src/sys/net/if.c:1.410 src/sys/net/if.c:1.411
--- src/sys/net/if.c:1.410 Fri Dec 8 04:03:51 2017
+++ src/sys/net/if.c Fri Dec 8 05:22:23 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: if.c,v 1.410 2017/12/08 04:03:51 ozaki-r Exp $ */
+/* $NetBSD: if.c,v 1.411 2017/12/08 05:22:23 ozaki-r Exp $ */
/*-
* Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc.
@@ -90,7 +90,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.410 2017/12/08 04:03:51 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.411 2017/12/08 05:22:23 ozaki-r Exp $");
#if defined(_KERNEL_OPT)
#include "opt_inet.h"
@@ -771,11 +771,9 @@ if_register(ifnet_t *ifp)
rt_ifannouncemsg(ifp, IFAN_ARRIVAL);
if (ifp->if_slowtimo != NULL) {
- int flags = ISSET(ifp->if_extflags, IFEF_MPSAFE) ?
- CALLOUT_MPSAFE : 0;
ifp->if_slowtimo_ch =
kmem_zalloc(sizeof(*ifp->if_slowtimo_ch), KM_SLEEP);
- callout_init(ifp->if_slowtimo_ch, flags);
+ callout_init(ifp->if_slowtimo_ch, 0);
callout_setfunc(ifp->if_slowtimo_ch, if_slowtimo, ifp);
if_slowtimo(ifp);
}
@@ -2539,18 +2537,6 @@ if_up_locked(struct ifnet *ifp)
}
/*
- * XXX reusing (ifp)->if_snd->ifq_lock rather than having another spin mutex
- * for each ifnet. It doesn't matter because:
- * - if IFEF_MPSAFE is enabled, if_snd isn't used and lock contention on
- * ifq_lock don't happen
- * - if IFEF_MPSAFE is disabled, there is no lock contention on ifq_lock
- * because if_snd and if_watchdog_reset is used with KERNEL_LOCK on packet
- * transmissions and if_slowtimo is also called with KERNEL_LOCK
- */
-#define IF_WATCHDOG_LOCK(ifp) mutex_enter((ifp)->if_snd.ifq_lock)
-#define IF_WATCHDOG_UNLOCK(ifp) mutex_exit((ifp)->if_snd.ifq_lock)
-
-/*
* Handle interface slowtimo timer routine. Called
* from softclock, we decrement timer (if set) and
* call the appropriate interface routine on expiration.
@@ -2561,40 +2547,21 @@ if_slowtimo(void *arg)
void (*slowtimo)(struct ifnet *);
struct ifnet *ifp = arg;
int s;
- bool fire;
slowtimo = ifp->if_slowtimo;
if (__predict_false(slowtimo == NULL))
return;
s = splnet();
- IF_WATCHDOG_LOCK(ifp);
- fire = (ifp->if_timer != 0 && --ifp->if_timer == 0);
- IF_WATCHDOG_UNLOCK(ifp);
- if (fire)
+ if (ifp->if_timer != 0 && --ifp->if_timer == 0)
(*slowtimo)(ifp);
+
splx(s);
if (__predict_true(ifp->if_slowtimo != NULL))
callout_schedule(ifp->if_slowtimo_ch, hz / IFNET_SLOWHZ);
}
-void
-if_watchdog_reset(struct ifnet *ifp, short v)
-{
-
- IF_WATCHDOG_LOCK(ifp);
- ifp->if_timer = v;
- IF_WATCHDOG_UNLOCK(ifp);
-}
-
-void
-if_watchdog_stop(struct ifnet *ifp)
-{
-
- if_watchdog_reset(ifp, 0);
-}
-
/*
* Mark an interface up and notify protocols of
* the transition.
Index: src/sys/net/if.h
diff -u src/sys/net/if.h:1.250 src/sys/net/if.h:1.251
--- src/sys/net/if.h:1.250 Fri Dec 8 04:03:51 2017
+++ src/sys/net/if.h Fri Dec 8 05:22:23 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: if.h,v 1.250 2017/12/08 04:03:51 ozaki-r Exp $ */
+/* $NetBSD: if.h,v 1.251 2017/12/08 05:22:23 ozaki-r Exp $ */
/*-
* Copyright (c) 1999, 2000, 2001 The NetBSD Foundation, Inc.
@@ -1045,9 +1045,6 @@ bool if_held(struct ifnet *);
void if_input(struct ifnet *, struct mbuf *);
-void if_watchdog_reset(struct ifnet *, short);
-void if_watchdog_stop(struct ifnet *);
-
struct if_percpuq *
if_percpuq_create(struct ifnet *);
void if_percpuq_destroy(struct if_percpuq *);
