Module Name: src
Committed By: riastradh
Date: Mon Jul 17 21:51:31 UTC 2023
Modified Files:
src/sys/kern: kern_tc.c
Log Message:
timecounter(9): Use atomic_store_release/load_consume for timehands.
This probably fixes real bugs on Alpha and makes the synchronization
pattern clearer everywhere.
To generate a diff of this commit:
cvs rdiff -u -r1.71 -r1.72 src/sys/kern/kern_tc.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/kern_tc.c
diff -u src/sys/kern/kern_tc.c:1.71 src/sys/kern/kern_tc.c:1.72
--- src/sys/kern/kern_tc.c:1.71 Mon Jul 17 21:51:20 2023
+++ src/sys/kern/kern_tc.c Mon Jul 17 21:51:30 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_tc.c,v 1.71 2023/07/17 21:51:20 riastradh Exp $ */
+/* $NetBSD: kern_tc.c,v 1.72 2023/07/17 21:51:30 riastradh Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -40,7 +40,7 @@
#include <sys/cdefs.h>
/* __FBSDID("$FreeBSD: src/sys/kern/kern_tc.c,v 1.166 2005/09/19 22:16:31 andre Exp $"); */
-__KERNEL_RCSID(0, "$NetBSD: kern_tc.c,v 1.71 2023/07/17 21:51:20 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_tc.c,v 1.72 2023/07/17 21:51:30 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_ntp.h"
@@ -466,7 +466,7 @@ binuptime(struct bintime *bt)
__insn_barrier();
do {
- th = timehands;
+ th = atomic_load_consume(&timehands);
gen = th->th_generation;
*bt = th->th_offset;
bintime_addx(bt, th->th_scale * tc_delta(th));
@@ -535,7 +535,7 @@ getbinuptime(struct bintime *bt)
TC_COUNT(ngetbinuptime);
do {
- th = timehands;
+ th = atomic_load_consume(&timehands);
gen = th->th_generation;
*bt = th->th_offset;
} while (gen == 0 || gen != th->th_generation);
@@ -549,7 +549,7 @@ getnanouptime(struct timespec *tsp)
TC_COUNT(ngetnanouptime);
do {
- th = timehands;
+ th = atomic_load_consume(&timehands);
gen = th->th_generation;
bintime2timespec(&th->th_offset, tsp);
} while (gen == 0 || gen != th->th_generation);
@@ -563,7 +563,7 @@ getmicrouptime(struct timeval *tvp)
TC_COUNT(ngetmicrouptime);
do {
- th = timehands;
+ th = atomic_load_consume(&timehands);
gen = th->th_generation;
bintime2timeval(&th->th_offset, tvp);
} while (gen == 0 || gen != th->th_generation);
@@ -578,7 +578,7 @@ getbintime(struct bintime *bt)
TC_COUNT(ngetbintime);
do {
- th = timehands;
+ th = atomic_load_consume(&timehands);
gen = th->th_generation;
*bt = th->th_offset;
} while (gen == 0 || gen != th->th_generation);
@@ -594,7 +594,7 @@ dogetnanotime(struct timespec *tsp)
TC_COUNT(ngetnanotime);
do {
- th = timehands;
+ th = atomic_load_consume(&timehands);
gen = th->th_generation;
*tsp = th->th_nanotime;
} while (gen == 0 || gen != th->th_generation);
@@ -624,7 +624,7 @@ getmicrotime(struct timeval *tvp)
TC_COUNT(ngetmicrotime);
do {
- th = timehands;
+ th = atomic_load_consume(&timehands);
gen = th->th_generation;
*tvp = th->th_microtime;
} while (gen == 0 || gen != th->th_generation);
@@ -839,7 +839,7 @@ uint64_t
tc_getfrequency(void)
{
- return timehands->th_counter->tc_frequency;
+ return atomic_load_consume(&timehands)->th_counter->tc_frequency;
}
/*
@@ -1015,8 +1015,7 @@ tc_windup(void)
* globally visible before changing.
*/
setrealuptime(th->th_microtime.tv_sec, th->th_offset.sec);
- membar_producer();
- timehands = th;
+ atomic_store_release(&timehands, th);
/*
* Force users of the old timehand to move on. This is
