|Summary:||Suspend to RAM resume hangs on a tickless (NO_HZ) kernel|
|Product:||Power Management||Reporter:||Almonas Petrasevicius (draugaz)|
|Component:||Hibernation/Suspend||Assignee:||Rafael J. Wysocki (rjwysocki)|
|Severity:||normal||CC:||m.dubovy, rjwysocki, svs1957, tglx|
|Bug Depends on:|
Config with NO_HZ set
Kernel log w/o no_hz option (suspends and resumes just fine)
Kernel log with no_hz option (suspends but not resumes)
Kernel log with no_hz and hpet=disable boot option
Kernel log with no_hz and compiled without hpet support (irq balancing too, but I think it is irrelevant)
Ubuntu kernel 2.6.22-14 log with no_hz and hpet=disable boot option
Kernel v2.6.24rc3 log with no_hz and hpet
Kernel v2.6.24rc3 log with no_hz and hpet
kernel log - NO_HZ enabled
kernel log for suspend/resume with hpet=disable
Description Almonas Petrasevicius 2007-11-01 14:43:54 UTC
Most recent kernel where this bug did not occur: unknown Distribution: Ubuntu 7.10 Hardware Environment: HP nc6320 T2400 945GM Problem Description: notebook hangs on resume after suspend to RAM with tickless (NO_HZ) kernel. This happens both with stock ubuntu 7.10 kernel 2.6.22-14 and with a self compiled vanilla 2.6.23 kernel. It looks like the kernel hangs in a pretty early stage of resume, fan does not even spin down after initial power on spin-up, there is no HDD activity, network interface is dead. Otherwise, notebook resumes just fine with exactly the same kernel configuration w/o NO_HZ config option.
Comment 1 Thomas Gleixner 2007-11-13 06:34:14 UTC
Can you trick the box into booting when you hit keys on the keyboard or is it completely dead ? Can you please provide your .config and a bootlog of 2.6.23 ? Thanks, tglx
Comment 2 Almonas Petrasevicius 2007-11-14 15:45:39 UTC
Created attachment 13550 [details] Config with NO_HZ set
Comment 3 Almonas Petrasevicius 2007-11-14 15:47:40 UTC
Created attachment 13551 [details] Kernel log w/o no_hz option (suspends and resumes just fine)
Comment 4 Almonas Petrasevicius 2007-11-14 15:48:35 UTC
Created attachment 13552 [details] Kernel log with no_hz option (suspends but not resumes)
Comment 5 Almonas Petrasevicius 2007-11-14 16:04:59 UTC
The box is completely dead, key presses don't do anything. I have attached two kernel logs: one without NO_HZ and another compiled with exactly the same parameters, just with NO_HZ option defined. As far as I can see, the NO_HZ kernel does not even suspend properly, the log ends at "Nov 15 00:02:49 notebook kernel: [12863.511592] PM: Preparing system for mem sleep" and that's all. But the notebook still enters the STR. The following line (kernel 2.6.22-14) comes already after power cycle. The second log shows successful suspends with kernel 2.6.23 without no_hz option.
Comment 6 Thomas Gleixner 2007-11-14 16:37:59 UTC
Almonas, thanks for providing the data. Can you please add "hpet=disable" to the kernel command line Thanks, tglx
Comment 7 Almonas Petrasevicius 2007-11-15 22:24:05 UTC
Yes, this definitely helps. Without HPET timer notebook suspends and resumes just fine, even with NO_HZ option. Is it something already known, or I could somehow help further debugging?
Comment 8 Thomas Gleixner 2007-11-16 15:10:15 UTC
Can you please provide the dmesg output of a boot with hpet=disable on the command line ? Thanks, tglx
Comment 9 Almonas Petrasevicius 2007-11-18 09:51:47 UTC
Created attachment 13599 [details] Kernel log with no_hz and hpet=disable boot option
Comment 10 Almonas Petrasevicius 2007-11-18 09:53:03 UTC
Created attachment 13600 [details] Kernel log with no_hz and compiled without hpet support (irq balancing too, but I think it is irrelevant)
Comment 11 Almonas Petrasevicius 2007-11-18 10:02:36 UTC
The second log has actually two suspend-resume cycles. On the last cycle (where the log ends) notebook resumed, but did not switched back to the graphical mode. Changing VT's did not help, the console #7 remained in text mode. Which I have never seen with an earlier kernel versions. It could be just a random failure, I am unable to reproduce it anymore.
Comment 12 Almonas Petrasevicius 2007-11-18 11:17:43 UTC
Created attachment 13602 [details] Ubuntu kernel 2.6.22-14 log with no_hz and hpet=disable boot option I have also tried the "stock" Ubuntu kernel v2.6.22-14 with an hpet=disable boot option. Unlike the self compiled "vanilla" kernel v2.6.23 this kernel does not resume even with an hpet=disable. The log ends here, but I think it is just missing the last lines. It seems like syslog buffers are not properly sync'ed before suspending.
Comment 13 Thomas Gleixner 2007-11-18 12:46:19 UTC
Hmm, strange. Does 2.6.24-rc3 show the same problem ?
Comment 14 Almonas Petrasevicius 2007-11-20 10:03:58 UTC
No, the 2.6.24-rc3 suspends and resumes just fine (with no_hz and without hpet compiled in).
Comment 15 Thomas Gleixner 2007-11-20 14:38:51 UTC
What happens when you add hpet ?
Comment 16 Almonas Petrasevicius 2007-11-26 07:48:55 UTC
Created attachment 13760 [details] Kernel v2.6.24rc3 log with no_hz and hpet 2.6.24-rc3 suspends and resumes just fine even with both no_hz and hpet enabled.
Comment 17 Almonas Petrasevicius 2007-11-26 07:52:20 UTC
Created attachment 13761 [details] Kernel v2.6.24rc3 log with no_hz and hpet 2.6.24-rc3 suspends and resumes just fine even with both no_hz and hpet enabled.
Comment 18 Sergey Smirnov 2007-11-26 23:03:33 UTC
2.6.24-rc3 on ARM doesn't resume with hpet=disable and no_hz=disable.
Comment 19 Rafael J. Wysocki 2007-11-27 07:06:32 UTC
(In reply to comment #18) > 2.6.24-rc3 on ARM doesn't resume with hpet=disable and no_hz=disable. Can you open a separate bug for that, please?
Comment 20 Sergey Smirnov 2007-11-27 23:59:38 UTC
>> 2.6.24-rc3 on ARM doesn't resume with hpet=disable and no_hz=disable. >Can you open a separate bug for that, please? Sorry. PDA with 2.6.24-rc3 or 2.6.23 hangs only if it charge while suspend. I've open bug #9394.
Comment 21 Rafael J. Wysocki 2007-12-12 16:25:05 UTC
Well, since Almonas has confirmed that 2.6.24-rc3 suspends and resumes correctly, I think we can consider the problem as resolved. I'm closing this bug, please reopen if necessary.
Comment 22 Matej Dubovy 2008-04-28 15:47:43 UTC
Hello, the same problem still occur on laptop HP nx6310, T1300 (single CPU), 945GM, bios version F.0D Notebook hangs on resume even with new vanilla kernel 2.6.25. With NO_HZ =off option it resumes fine. In fact, with enabled NO_HZ option, it does not fully hang on, but after approx 5 min, it resumes and continue to working. Also, when I tried to force unload acpi module 'processor' (& thermal & acpi_cpufreq) before suspend, it resumes fine. (but functionality of thermal module loaded after resume not work). When I used hpet=disable option it resumes after approx 30-60 min. Could you please reopen this bug or I have to open another one?
Comment 23 Matej Dubovy 2008-04-28 15:50:31 UTC
Created attachment 15962 [details] kernel log - NO_HZ enabled