Re: PROBLEM: E6850 has an 8+ minute delay during boot

From: Mark Lord
Date: Fri Dec 14 2007 - 09:38:44 EST


Arun Thomas wrote:
...
[ 31.670148] TCP bind hash table entries: 65536 (order: 7, 524288 bytes)
[ 31.670351] TCP: Hash tables configured (established 131072 bind 65536)
[ 31.670391] TCP reno registered
[ 31.681591] checking if image is initramfs...<7>Switched to high
resolution mode on CPU 0
[ 540.133678] Clocksource tsc unstable (delta = 299978139535 ns)
[ 540.137708] Time: hpet clocksource has been installed.
[ 540.432798] it is
[ 541.570364] Freeing initrd memory: 44428k freed
[ 541.570748] audit: initializing netlink socket (disabled)
...

Ahh... BINGO!

This is very likely the same problem that I first reported back in 2.6.21(20?),
when NOHZ and HPET first came in!

It never occurred to me to wait a full 8-minutes though,
so I just rebooted again after a 1-2 minute wait each time.

Seen on Core2Duo T7400 and Core2Quad E6600 systems, with kernels 2.6.21/22
at various points. Not consistent -- sometimes it would boot after a few
attempts, sometimes not.

It always hung around the "Switched to high resolution mode" messages.

Thomas Gleixner wrote:
The problem is caused by an SMI during the calibration routine. We
really need to come up with a solid solution which does not rely on
the periodic timer coming in, when there is something else (HPET,
pm_timer) available.
...

Oh good, an explanation!

Now we just need a creative fix.

One thing that *might* be sufficient, would be to do the
delay loop calibration twice, and compare the results to
see if they're within 10% (pick a number) of each other.

Is there a flag or something that SMI sets that we could poll
before/after the calibration? That could be used to tell us
that it needs redoing ?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/