Messages in this thread | | | Date | Mon, 20 Nov 2006 16:14:47 -0600 | From | Clark Williams <> | Subject | Time warp on 2.6.19-rc6-rt4 |
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Ingo/Thomas/John/et al,
I've seen sporadic time warp messages while running my pi_stress program (http://people.redhat.com/williams/tests/pi_tests-1.7.tar.gz). The frequency of time warp occurrences has been gong down over time, but I just got one on a dual Opteron running 2.6.19-rc6-rt4:
- -------------- $ sudo ./pi_stress --signal Starting PI Stress test Test threads using scheduler policy: SCHED_FIFO Admin priority: 99 Reporter priority: 98 10 groups of 3 threads will be created High priority: 97 Med priority: 96 Low priority: 95 Admin threads running on processor: 0 Test threads running on processor: 1 Press Ctrl-C to stop test Current Inversions: 1032940 Stoppping test Total inversion performed: 6836686 - --------------
The Current Inversions line is dynamically updated, but after I noticed it had stopped updating, I looked a the console and found:
- -------------- BUG: time warp detected! prev > now, 10277e5c84132156 > 10277e5b6c9e0baf: = 4688516519 delta, on CPU#0
Call Trace: [<ffffffff8026e647>] dump_trace+0xaa/0x3f2 [<ffffffff8026e9c9>] show_trace+0x3a/0x58 [<ffffffff8026ec03>] dump_stack+0x15/0x17 [<ffffffff8025cd91>] getnstimeofday+0x142/0x150 [<ffffffff802a2aff>] sys_clock_gettime+0x4d/0x98 [<ffffffff802601cf>] system_call+0xef/0x15c DWARF2 unwinder stuck at system_call+0xef/0x15c
Leftover inexact backtrace:
skipping trace printing on CPU#0 != -1 hdb: lost interrupt hdb: lost interrupt - --------------
The system was still running, but in my test the timer wasn't updating. This was actually one of Ingo's prepackaged kernel-rt rpms, so I don't have much debug on.
Anything you want me to try?
Clark -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org
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