Date: Mon, 15 Mar 2021 06:23:15 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 791b89dad7c2 - stable/12 - Make kern.timecounter.hardware tunable Message-ID: <202103150623.12F6NFSG066525@gitrepo.freebsd.org>
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The branch stable/12 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=791b89dad7c2f13c00f6771891da2a8506a5544b commit 791b89dad7c2f13c00f6771891da2a8506a5544b Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2021-03-07 23:50:12 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2021-03-15 06:22:40 +0000 Make kern.timecounter.hardware tunable (cherry picked from commit 56b9bee63a42dbac712acf540f23a4c3dbd099a9) --- sys/kern/kern_tc.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) diff --git a/sys/kern/kern_tc.c b/sys/kern/kern_tc.c index f916cbc75ac8..7f9b48cb1dd4 100644 --- a/sys/kern/kern_tc.c +++ b/sys/kern/kern_tc.c @@ -136,6 +136,7 @@ SYSCTL_PROC(_kern_timecounter, OID_AUTO, alloweddeviation, volatile int rtc_generation = 1; static int tc_chosen; /* Non-zero if a specific tc was chosen via sysctl. */ +static char tc_from_tunable[16]; static void tc_windup(struct bintime *new_boottimebin); static void cpu_tick_calibrate(int); @@ -1195,11 +1196,17 @@ tc_init(struct timecounter *tc) return; if (tc->tc_quality < 0) return; - if (tc->tc_quality < timecounter->tc_quality) - return; - if (tc->tc_quality == timecounter->tc_quality && - tc->tc_frequency < timecounter->tc_frequency) - return; + if (tc_from_tunable[0] != '\0' && + strcmp(tc->tc_name, tc_from_tunable) == 0) { + tc_chosen = 1; + tc_from_tunable[0] = '\0'; + } else { + if (tc->tc_quality < timecounter->tc_quality) + return; + if (tc->tc_quality == timecounter->tc_quality && + tc->tc_frequency < timecounter->tc_frequency) + return; + } (void)tc->tc_get_timecount(tc); timecounter = tc; } @@ -1479,8 +1486,9 @@ sysctl_kern_timecounter_hardware(SYSCTL_HANDLER_ARGS) return (EINVAL); } -SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, CTLTYPE_STRING | CTLFLAG_RW, - 0, 0, sysctl_kern_timecounter_hardware, "A", +SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, + CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, 0, 0, + sysctl_kern_timecounter_hardware, "A", "Timecounter hardware selected"); @@ -1918,6 +1926,9 @@ inittimehands(void *dummy) for (i = 1, thp = &ths[0]; i < timehands_count; thp = &ths[i++]) thp->th_next = &ths[i]; thp->th_next = &ths[0]; + + TUNABLE_STR_FETCH("kern.timecounter.hardware", tc_from_tunable, + sizeof(tc_from_tunable)); } SYSINIT(timehands, SI_SUB_TUNABLES, SI_ORDER_ANY, inittimehands, NULL);
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