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