diff options
Diffstat (limited to 'usr/src/uts/common/os/timers.c')
| -rw-r--r-- | usr/src/uts/common/os/timers.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/usr/src/uts/common/os/timers.c b/usr/src/uts/common/os/timers.c index e656a17088..38881be61e 100644 --- a/usr/src/uts/common/os/timers.c +++ b/usr/src/uts/common/os/timers.c @@ -1,5 +1,5 @@ /* - * Copyright 2007 Sun Microsystems, Inc. All rights reserved. + * Copyright 2006 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ @@ -850,6 +850,28 @@ timespectohz(timespec_t *tv, timespec_t now) } /* + * Same as timespectohz() except that we adjust the clock ticks down a bit. + * If we will be waiting for a long time, we may encounter skewing problems + * due to adjtime() system calls. Since we can skew up to 1/16 lbolt rate + * if adjtime is going crazy, we reduce the time delta since timeout() takes + * clock ticks rather than wallclock elapsed time. This may cause the caller + * (who calls timeout()) to return with a timeout prematurely and callers + * must accommodate this. See lwp_timeout(), queue_lwptimer() and + * cv_waituntil_sig(), currently the only callers of this function. + */ +clock_t +timespectohz_adj(timespec_t *tv, timespec_t now) +{ + timespec_t wait_time = *tv; + + timespecsub(&wait_time, &now); + wait_time.tv_sec -= wait_time.tv_sec >> 4; + wait_time.tv_nsec -= wait_time.tv_nsec >> 4; + timespecadd(&wait_time, &now); + return (timespectohz(&wait_time, now)); +} + +/* * hrt2ts(): convert from hrtime_t to timestruc_t. * * All this routine really does is: @@ -1162,6 +1184,7 @@ nanosleep(timespec_t *rqtp, timespec_t *rmtp) timespec_t rqtime; timespec_t rmtime; timespec_t now; + int timecheck; int ret = 1; model_t datamodel = get_udatamodel(); @@ -1181,11 +1204,12 @@ nanosleep(timespec_t *rqtp, timespec_t *rmtp) return (set_errno(EINVAL)); if (timerspecisset(&rqtime)) { + timecheck = timechanged; gethrestime(&now); timespecadd(&rqtime, &now); mutex_enter(&curthread->t_delay_lock); while ((ret = cv_waituntil_sig(&curthread->t_delay_cv, - &curthread->t_delay_lock, &rqtime)) > 0) + &curthread->t_delay_lock, &rqtime, timecheck)) > 0) continue; mutex_exit(&curthread->t_delay_lock); } |