[src/trunk]: src/sys/dev/scsipi Improve the workqueue and callout handling. ...

[jdc <jdc%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9d9b1b5c4084
branches:  trunk
changeset: 1012321:9d9b1b5c4084
user:      jdc <jdc%NetBSD.org@localhost>
date:      Mon Jul 27 15:41:03 2020 +0000

description:
Improve the workqueue and callout handling.  Prompted by riastradh@.

diffstat:

 sys/dev/scsipi/if_se.c |  45 ++++++++++++++++++++++-----------------------
 1 files changed, 22 insertions(+), 23 deletions(-)

diffs (129 lines):

diff -r 75f39be9eb46 -r 9d9b1b5c4084 sys/dev/scsipi/if_se.c
--- a/sys/dev/scsipi/if_se.c    Mon Jul 27 14:52:55 2020 +0000
+++ b/sys/dev/scsipi/if_se.c    Mon Jul 27 15:41:03 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_se.c,v 1.110 2020/07/22 17:18:10 riastradh Exp $    */
+/*     $NetBSD: if_se.c,v 1.111 2020/07/27 15:41:03 jdc Exp $  */
 
 /*
  * Copyright (c) 1997 Ian W. Dall <ian.dall%dsto.defence.gov.au@localhost>
@@ -59,7 +59,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_se.c,v 1.110 2020/07/22 17:18:10 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_se.c,v 1.111 2020/07/27 15:41:03 jdc Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -332,6 +332,7 @@
 
        sc->sc_attach_state = 0;
        callout_init(&sc->sc_recv_ch, CALLOUT_MPSAFE);
+       callout_setfunc(&sc->sc_recv_ch, se_recv_callout, (void *)sc);
        mutex_init(&sc->sc_iflock, MUTEX_DEFAULT, IPL_SOFTNET);
 
        /*
@@ -415,7 +416,6 @@
                mutex_enter(&sc->sc_iflock);
                ifp->if_flags &= ~IFF_RUNNING;
                se_disable(sc);
-               callout_halt(&sc->sc_recv_ch, NULL);
                ether_ifdetach(ifp);
                if_detach(ifp);
                mutex_exit(&sc->sc_iflock);
@@ -464,18 +464,13 @@
 se_ifstart(struct ifnet *ifp)
 {
        struct se_softc *sc = ifp->if_softc;
-       int i = 100;
 
        mutex_enter(&sc->sc_iflock);
-       while (i && sc->sc_send_work_pending == true) {
-               i--;
-               delay(10);
-       }
-       if (i) {
+       if (!sc->sc_send_work_pending)  {
                sc->sc_send_work_pending = true;
                workqueue_enqueue(sc->sc_send_wq, &sc->sc_send_work, NULL);
-       } else
-               if_statinc(ifp, if_oerrors);
+       } 
+       /* else: nothing to do - work is already queued */
        mutex_exit(&sc->sc_iflock);
 }
 
@@ -575,8 +570,7 @@
                /* scsipi_free_xs will call start. Harmless. */
                if (error) {
                        /* Reschedule after a delay */
-                       callout_reset(&sc->sc_recv_ch, se_poll,
-                           se_recv_callout, (void *)sc);
+                       callout_schedule(&sc->sc_recv_ch, se_poll);
                } else {
                        int n, ntimeo;
                        n = se_read(sc, xs->data, xs->datalen - xs->resid);
@@ -597,8 +591,7 @@
                                          se_poll: ntimeo);
                        }
                        sc->sc_last_timeout = ntimeo;
-                       callout_reset(&sc->sc_recv_ch, ntimeo,
-                           se_recv_callout, (void *)sc);
+                       callout_schedule(&sc->sc_recv_ch, ntimeo);
                }
        }
 }
@@ -618,8 +611,8 @@
 
        mutex_enter(&sc->sc_iflock);
        if (sc->sc_recv_work_pending == true) {
-               callout_reset(&sc->sc_recv_ch, se_poll,
-                   se_recv_callout, (void *)sc);
+               callout_schedule(&sc->sc_recv_ch, se_poll);
+               mutex_exit(&sc->sc_iflock);
                return;
        }
 
@@ -660,8 +653,7 @@
            sc->sc_rbuf, RBUF_LEN, SERETRIES, SETIMEOUT, NULL,
            XS_CTL_NOSLEEP | XS_CTL_DATA_IN);
        if (error)
-               callout_reset(&sc->sc_recv_ch, se_poll,
-                   se_recv_callout, (void *)sc);
+               callout_schedule(&sc->sc_recv_ch, se_poll);
 }
 
 /*
@@ -923,12 +915,19 @@
        if ((ifp->if_flags & (IFF_RUNNING | IFF_UP)) == IFF_UP) {
                ifp->if_flags |= IFF_RUNNING;
                mutex_enter(&sc->sc_iflock);
-               sc->sc_recv_work_pending = true;
-               workqueue_enqueue(sc->sc_recv_wq, &sc->sc_recv_work, NULL);
+               if (!sc->sc_recv_work_pending)  {
+                       sc->sc_recv_work_pending = true;
+                       workqueue_enqueue(sc->sc_recv_wq, &sc->sc_recv_work,
+                           NULL);
+               } 
                mutex_exit(&sc->sc_iflock);
                ifp->if_flags &= ~IFF_OACTIVE;
                mutex_enter(&sc->sc_iflock);
-               workqueue_enqueue(sc->sc_send_wq, &sc->sc_send_work, NULL);
+               if (!sc->sc_send_work_pending)  {
+                       sc->sc_send_work_pending = true;
+                       workqueue_enqueue(sc->sc_send_wq, &sc->sc_send_work,
+                           NULL);
+               } 
                mutex_exit(&sc->sc_iflock);
        }
        return (error);
@@ -1019,7 +1018,7 @@
 {
 
        /* Don't schedule any reads */
-       callout_stop(&sc->sc_recv_ch);
+       callout_halt(&sc->sc_recv_ch, &sc->sc_iflock);
 
        /* Wait for the workqueues to finish */
        mutex_enter(&sc->sc_iflock);