diff --git a/sys/kern/kern_tc.c b/sys/kern/kern_tc.c --- a/sys/kern/kern_tc.c +++ b/sys/kern/kern_tc.c @@ -141,6 +141,7 @@ 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); @@ -1215,11 +1216,17 @@ 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; } @@ -1500,7 +1507,7 @@ } SYSCTL_PROC(_kern_timecounter, OID_AUTO, hardware, - CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0, + CTLTYPE_STRING | CTLFLAG_RWTUN | CTLFLAG_NOFETCH | CTLFLAG_MPSAFE, 0, 0, sysctl_kern_timecounter_hardware, "A", "Timecounter hardware selected"); @@ -1940,6 +1947,9 @@ 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);