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author | phk <phk@FreeBSD.org> | 1998-11-23 09:59:02 +0000 |
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committer | phk <phk@FreeBSD.org> | 1998-11-23 09:59:02 +0000 |
commit | 1ca888b5fd87b8d85f835ab5cf2f42d45ca12791 (patch) | |
tree | ace8c5e23fa80b379a348a57347f6da2d66c64bc /sys/kern/kern_tc.c | |
parent | ba9fb96ddbb30995e96142bf949ea174ab702ba0 (diff) | |
download | FreeBSD-src-1ca888b5fd87b8d85f835ab5cf2f42d45ca12791.zip FreeBSD-src-1ca888b5fd87b8d85f835ab5cf2f42d45ca12791.tar.gz |
Make timecounters more resistant to badly behaved SW/HW which locks
out interrupts for too long. If you still see the "calcru: negative
time..." message you can increase NTIMECOUNTER (see LINT).
Sideeffect is that a timecounter is required to not wrap around in
less than (1 + delta) seconds instead of the (1/hz + delta) required
until now.
Many thanks to: msmith, wpaul, wosch & bde
Diffstat (limited to 'sys/kern/kern_tc.c')
-rw-r--r-- | sys/kern/kern_tc.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/sys/kern/kern_tc.c b/sys/kern/kern_tc.c index c712245..22005c2 100644 --- a/sys/kern/kern_tc.c +++ b/sys/kern/kern_tc.c @@ -37,7 +37,7 @@ * SUCH DAMAGE. * * @(#)kern_clock.c 8.5 (Berkeley) 1/21/94 - * $Id: kern_clock.c,v 1.83 1998/10/26 06:13:18 bde Exp $ + * $Id: kern_clock.c,v 1.84 1998/11/23 09:34:19 sos Exp $ */ #include <sys/param.h> @@ -67,11 +67,14 @@ #include <machine/smp.h> #endif +/* This is where the NTIMECOUNTER option hangs out */ +#include "opt_ntp.h" + /* * Number of timecounters used to implement stable storage */ #ifndef NTIMECOUNTER -#define NTIMECOUNTER 2 +#define NTIMECOUNTER 5 #endif static MALLOC_DEFINE(M_TIMECOUNTER, "timecounter", @@ -80,7 +83,7 @@ static MALLOC_DEFINE(M_TIMECOUNTER, "timecounter", static void initclocks __P((void *dummy)); SYSINIT(clocks, SI_SUB_CLOCKS, SI_ORDER_FIRST, initclocks, NULL) -static void tco_forward __P((void)); +static void tco_forward __P((int force)); static void tco_setscales __P((struct timecounter *tc)); static __inline unsigned tco_delta __P((struct timecounter *tc)); @@ -222,7 +225,7 @@ hardclock(frame) if (stathz == 0) statclock(frame); - tco_forward(); + tco_forward(0); ticks++; /* @@ -624,14 +627,14 @@ microuptime(struct timeval *tv) } void -nanouptime(struct timespec *tv) +nanouptime(struct timespec *ts) { unsigned count; u_int64_t delta; struct timecounter *tc; tc = (struct timecounter *)timecounter; - tv->tv_sec = tc->tc_offset_sec; + ts->tv_sec = tc->tc_offset_sec; count = tco_delta(tc); delta = tc->tc_offset_nano; delta += ((u_int64_t)count * tc->tc_scale_nano_f); @@ -639,9 +642,9 @@ nanouptime(struct timespec *tv) delta += ((u_int64_t)count * tc->tc_scale_nano_i); if (delta >= 1000000000) { delta -= 1000000000; - tv->tv_sec++; + ts->tv_sec++; } - tv->tv_nsec = delta; + ts->tv_nsec = delta; } static void @@ -709,7 +712,7 @@ set_timecounter(struct timespec *ts) boottime.tv_sec--; } /* fiddle all the little crinkly bits around the fiords... */ - tco_forward(); + tco_forward(1); } @@ -757,7 +760,7 @@ sync_other_counter(void) } static void -tco_forward(void) +tco_forward(int force) { struct timecounter *tc, *tco; @@ -777,6 +780,7 @@ tco_forward(void) if (timedelta != 0) { tc->tc_offset_nano += (u_int64_t)(tickdelta * 1000) << 32; timedelta -= tickdelta; + force++; } while (tc->tc_offset_nano >= 1000000000ULL << 32) { @@ -786,8 +790,12 @@ tco_forward(void) tc->tc_adjustment = tc->tc_tweak->tc_adjustment; ntp_update_second(tc); /* XXX only needed if xntpd runs */ tco_setscales(tc); + force++; } + if (!force) + return; + tc->tc_offset_micro = (tc->tc_offset_nano / 1000) >> 32; /* Figure out the wall-clock time */ |