Messages in this thread | | | Date | Thu, 19 Feb 2015 18:00:48 +0100 | From | Jiri Bohac <> | Subject | Re: [PATCH] time, ntp: Do not update time_state in middle of leap second [v3] |
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Hi,
I'm trying to understand what exactly is going on here...
On Thu, Feb 12, 2015 at 08:58:19AM -0500, Prarit Bhargava wrote: > The test did the following in userspace: > > tx.modes = ADJ_STATUS; > tx.status = STA_INS; > > /* send leap second request */ > ret = adjtimex(&tx); > > /* Check adjtimex output every half second */ > now = tx.time.tv_sec; > while (now < next_leap+2) { > char buf[26]; > ret = adjtimex(&tx); > > ctime_r(&tx.time.tv_sec, buf); > buf[strlen(buf)-1] = 0; /*remove trailing\n */ > > printf("%s + %6ld us\t%s\n", > buf, > tx.time.tv_usec, > time_state_str(ret)); > now = tx.time.tv_sec; > /* Sleep for another half second */ > ts.tv_sec = 0; > ts.tv_nsec = NSEC_PER_SEC/2; > clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL); > } > > After some investigation it was noted that the test contained a small error: > the test does not reinitialize tx.status and reissues the STA_INS every > 1/2 second.
Prarit, can you explain who sets the STA_PLL flag, so that process_adj_status() detects a STA_PLL->!STA_PLL transition and goes to the branch that sets time_state = TIME_OK?
Is that ntpd running in parallel with your test program? If that is the case, you would eventually end up oscilating between the the TIME_INS and TIME_OK states anyway, even with your patch. ntpd will clear the STA_INS flag after midnight, the state machine will transition from TIME_WAIT to TIME_OK and your test program will set STA_INS again (fighting with ntpd which will clear the flag from time to time) ... right?
Thanks,
-- Jiri Bohac <jbohac@suse.cz> SUSE Labs, SUSE CZ
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