diff options
| author | Konstantin Belousov <kib@FreeBSD.org> | 2019-09-09 11:29:58 +0000 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2021-11-15 08:56:53 +0100 |
| commit | 71b71d6ad2733f60845938cac3d51b9010d6f840 (patch) | |
| tree | 1f8c4de8a6fc9825419c8c50f2d9e1b1a8a286c9 /cpukit/score/src/kern_tc.c | |
| parent | Instead of using an incomplete list of platforms (diff) | |
| download | rtems-71b71d6ad2733f60845938cac3d51b9010d6f840.tar.bz2 | |
Make timehands count selectable at boottime.
Tested by: O'Connor, Daniel <darius@dons.net.au>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D21563
This patch was modified by Sebastian Huber
<sebastian.huber@embedded-brains.de> to adjust it for RTEMS. See
comment in the patch.
Diffstat (limited to '')
| -rw-r--r-- | cpukit/score/src/kern_tc.c | 50 |
1 files changed, 45 insertions, 5 deletions
diff --git a/cpukit/score/src/kern_tc.c b/cpukit/score/src/kern_tc.c index cc2b47aeb8..88680db2c3 100644 --- a/cpukit/score/src/kern_tc.c +++ b/cpukit/score/src/kern_tc.c @@ -184,6 +184,35 @@ struct timehands { struct timehands *th_next; }; +#ifndef __rtems__ +static struct timehands ths[16] = { + [0] = { + .th_counter = &dummy_timecounter, + .th_scale = (uint64_t)-1 / 1000000, + .th_offset = { .sec = 1 }, + .th_generation = 1, + }, +}; + +static struct timehands *volatile timehands = &ths[0]; +struct timecounter *timecounter = &dummy_timecounter; +static struct timecounter *timecounters = &dummy_timecounter; + +int tc_min_ticktock_freq = 1; +#else /* __rtems__ */ +/* + * In FreeBSD, the timehands count is a tuning option from two to 16. The + * tuning option was added since it is inexpensive and some FreeBSD users asked + * for it to play around. The default value is two. One system which did not + * work with two timehands was a system with one processor and a specific PPS + * device. + * + * For RTEMS, in uniprocessor configurations, just use one timehand since the + * update is done with interrupt disabled. + * + * In SMP configurations, use a fixed set of two timehands until someone + * reports an issue. + */ #if defined(RTEMS_SMP) static struct timehands th0; static struct timehands th1 = { @@ -210,10 +239,6 @@ static struct timehands th0 = { static struct timehands *volatile timehands = &th0; struct timecounter *timecounter = &dummy_timecounter; -#ifndef __rtems__ -static struct timecounter *timecounters = &dummy_timecounter; - -int tc_min_ticktock_freq = 1; #endif /* __rtems__ */ #ifndef __rtems__ @@ -236,6 +261,10 @@ static int timestepwarnings; SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RW, ×tepwarnings, 0, "Log time steps"); +static int timehands_count = 2; +SYSCTL_INT(_kern_timecounter, OID_AUTO, timehands_count, CTLFLAG_RDTUN, + &timehands_count, 0, "Count of timehands in rotation"); + struct bintime bt_timethreshold; struct bintime bt_tickthreshold; sbintime_t sbt_timethreshold; @@ -2233,8 +2262,9 @@ done: static void inittimecounter(void *dummy) { + struct timehands *thp; u_int p; - int tick_rate; + int i, tick_rate; /* * Set the initial timeout to @@ -2260,6 +2290,16 @@ inittimecounter(void *dummy) #ifdef FFCLOCK ffclock_init(); #endif + + /* Set up the requested number of timehands. */ + if (timehands_count < 1) + timehands_count = 1; + if (timehands_count > nitems(ths)) + timehands_count = nitems(ths); + for (i = 1, thp = &ths[0]; i < timehands_count; thp = &ths[i++]) + thp->th_next = &ths[i]; + thp->th_next = &ths[0]; + /* warm up new timecounter (again) and get rolling. */ (void)timecounter->tc_get_timecount(timecounter); (void)timecounter->tc_get_timecount(timecounter); |