warn_on regression after 2.6.27-rc5

From: Christian Borntraeger
Date: Wed Sep 10 2008 - 04:10:40 EST

Hello Thomas,

this commit

commit 1fb9b7d29d8e85ba3196eaa7ab871bf76fc98d36
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Date: Wed Sep 3 21:37:14 2008 +0000

clockevents: prevent endless loop lockup

causes the following warning on my Thinkpad T61p:

CE: __tick_program_event of hpet is stuck 7416220944 7416221ccc
CE: increasing min_delta_ns 5000 to 10000 nsec
------------[ cut here ]------------
WARNING: at kernel/time/tick-oneshot.c:52 tick_dev_program_event+0xd6/0x120()
Modules linked in: kvm_intel kvm fan iptable_nat nf_nat iptable_mangle
ipt_REJECT nf_conntrack_ipv4 xt_state nf_conntrack iptable_filter ip_tables
x_tables ctr blowfish rmd160 sha256_generic crypto_null nls_utf8 ntfs fuse
acpi_cpufreq usbhid pcmcia snd_hda_intel snd_pcm_oss snd_mixer_oss snd_pcm
snd_timer snd_page_alloc snd_hwdep snd yenta_socket iwlagn rsrc_nonstatic
pcmcia_core soundcore ehci_hcd uhci_hcd e1000e thermal evdev video battery
usbcore ac bay processor button
Pid: 0, comm: swapper Not tainted 2.6.27-rc5-00319-g7686ad5 #15
[<c012e32f>] warn_on_slowpath+0x5f/0xa0
[<c026f950>] vt_console_print+0x0/0x330
[<c03f0554>] _spin_lock_irqsave+0x34/0x50
[<c012eb71>] release_console_sem+0x191/0x1c0
[<c012f0ce>] vprintk+0x32e/0x3a0
[<c01487d1>] getnstimeofday+0x41/0xf0
[<c0114d88>] lapic_next_event+0x18/0x30
[<c01487d1>] getnstimeofday+0x41/0xf0
[<c014bd73>] clockevents_program_event+0xa3/0x160
[<c014cfe6>] tick_dev_program_event+0xd6/0x120
[<c014c81d>] tick_broadcast_oneshot_control+0x10d/0x120
[<c014c3a5>] tick_notify+0x295/0x3c0
[<c0146df6>] notifier_call_chain+0x36/0x70
[<c0146ee7>] raw_notifier_call_chain+0x17/0x20
[<c014bbbe>] clockevents_notify+0x1e/0x70
[<f884f087>] acpi_idle_enter_bm+0x15e/0x2c2 [processor]
[<c031fed3>] cpuidle_idle_call+0x73/0xd0
[<c010249d>] cpu_idle+0x6d/0x140
---[ end trace c7d6f2472868c172 ]---

While I agree with doubling the time, I am not sure if a WARN_ON is
appropriate. After all the code is able to fix the timer setting.

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