[src/trunk]: src/sys/dev/sysmon - Call selnotify() with sysmon_power_event_qu...

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

details:   https://anonhg.NetBSD.org/src/rev/507ea7cd75dc
branches:  trunk
changeset: 1023804:507ea7cd75dc
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Sun Sep 26 16:24:21 2021 +0000

description:
- Call selnotify() with sysmon_power_event_queue_mtx held, passing the
  correct hints.  Adjust filt_sysmon_power_read() accordingly (assert
  that the mutex is held iff NOTE_SUBMIT).
- Mark sysmon_power_read_filtops as MPSAFE.
- Use seltrue_filtops rather than rolling our own with filt_seltrue.

diffstat:

 sys/dev/sysmon/sysmon_power.c |  37 +++++++++++++++++++------------------
 1 files changed, 19 insertions(+), 18 deletions(-)

diffs (93 lines):

diff -r 67478996d513 -r 507ea7cd75dc sys/dev/sysmon/sysmon_power.c
--- a/sys/dev/sysmon/sysmon_power.c     Sun Sep 26 15:58:33 2021 +0000
+++ b/sys/dev/sysmon/sysmon_power.c     Sun Sep 26 16:24:21 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sysmon_power.c,v 1.67 2021/09/26 01:16:09 thorpej Exp $        */
+/*     $NetBSD: sysmon_power.c,v 1.68 2021/09/26 16:24:21 thorpej Exp $        */
 
 /*-
  * Copyright (c) 2007 Juan Romero Pardines.
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sysmon_power.c,v 1.67 2021/09/26 01:16:09 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sysmon_power.c,v 1.68 2021/09/26 16:24:21 thorpej Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_compat_netbsd.h"
@@ -419,8 +419,9 @@
                ped->flags |= SYSMON_POWER_DICTIONARY_READY;
                SIMPLEQ_INSERT_TAIL(&pev_dict_list, ped, pev_dict_head);
                cv_broadcast(&sysmon_power_event_queue_cv);
+               selnotify(&sysmon_power_event_queue_selinfo,
+                   POLLIN | POLLRDNORM, NOTE_SUBMIT);
                mutex_exit(&sysmon_power_event_queue_mtx);
-               selnotify(&sysmon_power_event_queue_selinfo, 0, 0);
        }
 
 out:
@@ -546,27 +547,28 @@
 filt_sysmon_power_read(struct knote *kn, long hint)
 {
 
-       mutex_enter(&sysmon_power_event_queue_mtx);
+       if (hint & NOTE_SUBMIT) {
+               KASSERT(mutex_owned(&sysmon_power_event_queue_mtx));
+       } else {
+               mutex_enter(&sysmon_power_event_queue_mtx);
+       }
+
        kn->kn_data = sysmon_power_event_queue_count;
-       mutex_exit(&sysmon_power_event_queue_mtx);
+
+       if ((hint & NOTE_SUBMIT) == 0) {
+               mutex_exit(&sysmon_power_event_queue_mtx);
+       }
 
        return kn->kn_data > 0;
 }
 
 static const struct filterops sysmon_power_read_filtops = {
-       .f_flags = FILTEROP_ISFD,
+       .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
        .f_attach = NULL,
        .f_detach = filt_sysmon_power_rdetach,
        .f_event = filt_sysmon_power_read,
 };
 
-static const struct filterops sysmon_power_write_filtops = {
-       .f_flags = FILTEROP_ISFD,
-       .f_attach = NULL,
-       .f_detach = filt_sysmon_power_rdetach,
-       .f_event = filt_seltrue,
-};
-
 /*
  * sysmonkqfilter_power:
  *
@@ -579,20 +581,19 @@
        switch (kn->kn_filter) {
        case EVFILT_READ:
                kn->kn_fop = &sysmon_power_read_filtops;
+               mutex_enter(&sysmon_power_event_queue_mtx);
+               selrecord_knote(&sysmon_power_event_queue_selinfo, kn);
+               mutex_exit(&sysmon_power_event_queue_mtx);
                break;
 
        case EVFILT_WRITE:
-               kn->kn_fop = &sysmon_power_write_filtops;
+               kn->kn_fop = &seltrue_filtops;
                break;
 
        default:
                return EINVAL;
        }
 
-       mutex_enter(&sysmon_power_event_queue_mtx);
-       selrecord_knote(&sysmon_power_event_queue_selinfo, kn);
-       mutex_exit(&sysmon_power_event_queue_mtx);
-
        return 0;
 }