[gentoo-user] clock skew corrupts kernel builds?

[James]

Hello,

I adjusted my time with the 'date' command. The system then complained
about the time zone and told me to fix is using 'zic'

OK, so I issued 'zic -l EST'.......

Everything is correct (i think) here my rc.conf entry:

CLOCK="local"

But when I build a new kernel, I get:
make: warning: Clock skew detected. Your build may be incomplete.

waz_up with this?

Did I miss something? The clock in the kde menu bar is correct, and matches
what I get when querying the system time with 'date'....

Enlightenment would be appreciated...

James


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[Bastian Balthazar Bux]

Post by James
Hello,
I adjusted my time with the 'date' command. The system then complained
about the time zone and told me to fix is using 'zic'
OK, so I issued 'zic -l EST'.......
CLOCK="local"
make: warning: Clock skew detected. Your build may be incomplete.
waz_up with this?
Did I miss something? The clock in the kde menu bar is correct, and matches
what I get when querying the system time with 'date'....
Enlightenment would be appreciated...
James
--

As Far As I Know (not so far)
After the first time you compile some source, if you compile again make
try to avoid recompile unchanged source.
The check is done on the dates of source code and the one of object
built. Change the clock of the computer from the first compile to the
second one may make it confused and so it can avoid to recompile source
that is changed.
About the kernel compile, I suggesto to copy your .config somewhere
safe, run "make mrproper" or "make clean" (first preferred), copy
.config again in /usr/src/linux and recompile.

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[Jonathan Nichols]

Post by James
make: warning: Clock skew detected. Your build may be incomplete.
waz_up with this?
Did I miss something? The clock in the kde menu bar is correct, and matches
what I get when querying the system time with 'date'....
Enlightenment would be appreciated...

What about the date in the BIOS? I've seen that error before and
correcting the computer's BIOS date resolved the issue. Sure, you have
to reboot, but oh well.. :-)


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[Bastian Balthazar Bux]

Post by Jonathan Nichols

Post by James
make: warning: Clock skew detected. Your build may be incomplete.
waz_up with this?
Did I miss something? The clock in the kde menu bar is correct, and matches
what I get when querying the system time with 'date'....
Enlightenment would be appreciated...

What about the date in the BIOS? I've seen that error before and
correcting the computer's BIOS date resolved the issue. Sure, you have
to reboot, but oh well.. :-)

instead of a simply "date -set" ?

Post by Jonathan Nichols
--

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[Lluís Batlle i Rossell]

I use, in those situations, 'hwclock' to set or take care of the hardware clock.
(referred as the BIOS date) :)

Post by Bastian Balthazar Bux

Post by Jonathan Nichols

Post by James
make: warning: Clock skew detected. Your build may be incomplete.
waz_up with this?
Did I miss something? The clock in the kde menu bar is correct, and matches
what I get when querying the system time with 'date'....
Enlightenment would be appreciated...

What about the date in the BIOS? I've seen that error before and
correcting the computer's BIOS date resolved the issue. Sure, you have
to reboot, but oh well.. :-)

instead of a simply "date -set" ?

Post by Jonathan Nichols
--

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| Lluís Batlle i Rossell |Tel.Olot. 972 26 71 24|
| Membre de [s3os] (www.s3os.net) | BCN. 93 16 22 680|
| ***@jabber.org / ICQ# 9658637 | Mòb. 654 08 67 35|
| +info personal: http://vicerveza.homeunix.net/~viric/ | Santa Pau / Catalunya|
+-------------------------------------------------------+----------------------+
Cita:
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(Dell Computers)

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[Uwe Thiem]

Post by Bastian Balthazar Bux

Post by Jonathan Nichols

Post by James
make: warning: Clock skew detected. Your build may be incomplete.
waz_up with this?
Did I miss something? The clock in the kde menu bar is correct, and matches
what I get when querying the system time with 'date'....
Enlightenment would be appreciated...

What about the date in the BIOS? I've seen that error before and
correcting the computer's BIOS date resolved the issue. Sure, you have
to reboot, but oh well.. :-)

instead of a simply "date -set" ?

Nope. Date sets the system clock rather than the hardware clock. Try "hwclock
-w" or "hwclock -wu" depending whether you want your clock running GMT or
local time.

Uwe

[james]

Post by Uwe Thiem
Nope. Date sets the system clock rather than the hardware clock. Try "hwclock
-w" or "hwclock -wu" depending whether you want your clock running GMT or
local time.

Very Interesting util that hwclock. However, when I ran 'hwclock -r' on 2
different gentoo systems, they match the system time rendered by 'date'.

That was unexpected, as I believe the bios time has never been synce up in
since these are relatively new systems that I control. Maybe the bios or using
i2c or acpi synced up the bios(haredware time) to the system time.

Any way, it's good enough to know about hwclock, and when I roll out
NTP, I'll delved deeper into this util....

*THANKS*
James


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[Nick Rout]

Post by james

Post by Uwe Thiem
Nope. Date sets the system clock rather than the hardware clock. Try "hwclock
-w" or "hwclock -wu" depending whether you want your clock running GMT or
local time.

Very Interesting util that hwclock. However, when I ran 'hwclock -r' on 2
different gentoo systems, they match the system time rendered by 'date'.
That was unexpected, as I believe the bios time has never been synce up in
since these are relatively new systems that I control. Maybe the bios or using
i2c or acpi synced up the bios(haredware time) to the system time.
Any way, it's good enough to know about hwclock, and when I roll out
NTP, I'll delved deeper into this util....

hwclock is run by /etc/init.d/clock on startup and shutdown. there
should be no need to use it in normal usage of a gentoo system.

Post by james
*THANKS*
James
--

[Lluís Batlle i Rossell]

Yes, there's something important about hwclock.

hwclock corrects the clock 'skew' done by the hardware clock.
Hardware clocks are usually 'low quality clocks', and 'hwclock' uses the
system-clock for knowing HOW MUCH the hardware clock skewed.

So, there is a file, /etc/adjtime, used by hwclock to correct the clock.

If you make strange changes in your bios date, and in system date, etc (that is,
setting the time when the clock _totally misses_ the real time), you have to
remove that file, and let 'hwclock' start calculating the 'skew' again.

In that file there may be a correction of "1h for 1 minute", and then your
system clock will change suddenly from your hardware clock, at boot.

Simply, if you have clock problems, remove /etc/adjtime, and let hwclock create
it again (you have to touch nothing :).

Post by Nick Rout

Post by james

Post by Uwe Thiem
Nope. Date sets the system clock rather than the hardware clock. Try "hwclock
-w" or "hwclock -wu" depending whether you want your clock running GMT or
local time.

Very Interesting util that hwclock. However, when I ran 'hwclock -r' on 2
different gentoo systems, they match the system time rendered by 'date'.
That was unexpected, as I believe the bios time has never been synce up in
since these are relatively new systems that I control. Maybe the bios or using
i2c or acpi synced up the bios(haredware time) to the system time.
Any way, it's good enough to know about hwclock, and when I roll out
NTP, I'll delved deeper into this util....

hwclock is run by /etc/init.d/clock on startup and shutdown. there
should be no need to use it in normal usage of a gentoo system.

Post by james
*THANKS*
James
--

--
--

--
+-------------------------------------------------------+----------------------+
| Lluís Batlle i Rossell |Tel.Olot. 972 26 71 24|
| Membre de [s3os] (www.s3os.net) | BCN. 93 16 22 680|
| ***@jabber.org / ICQ# 9658637 | Mòb. 654 08 67 35|
| +info personal: http://vicerveza.homeunix.net/~viric/ | Santa Pau / Catalunya|
+-------------------------------------------------------+----------------------+
Cita:
- Press any key to accept the license.
(Dell Computers)

--
gentoo-***@gentoo.org mailing list

[James]

Post by Lluís Batlle i Rossell
hwclock corrects the clock 'skew' done by the hardware clock.
Hardware clocks are usually 'low quality clocks', and 'hwclock' uses the
system-clock for knowing HOW MUCH the hardware clock skewed.
So, there is a file, /etc/adjtime, used by hwclock to correct the clock.
If you make strange changes in your bios date, and in system date, etc (that is,
setting the time when the clock _totally misses_ the real time), you have to
remove that file, and let 'hwclock' start calculating the 'skew' again.
In that file there may be a correction of "1h for 1 minute", and then your
system clock will change suddenly from your hardware clock, at boot.
Simply, if you have clock problems, remove /etc/adjtime, and let hwclock create
it again (you have to touch nothing :).

Thanks for the explainations (Everyone) this is good to know exactly how the
bios clock and the system clocks work....

Thanks Everyone for clearing this up for me.

James


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[Neil Bothwick]

Post by Nick Rout
hwclock is run by /etc/init.d/clock on startup and shutdown. there
should be no need to use it in normal usage of a gentoo system.

From /etc/conf.d/clock

# If you want to sync the system clock to the hardware clock during
# shutdown, then say "yes" here.

CLOCK_SYSTOHC="yes"

It defaults to no.

[James]

Post by Bastian Balthazar Bux

Post by James
I adjusted my time with the 'date' command. The system then complained
about the time zone and told me to fix is using 'zic'

.org mailing list

Post by Bastian Balthazar Bux
As Far As I Know (not so far)
After the first time you compile some source, if you compile again make
try to avoid recompile unchanged source.
The check is done on the dates of source code and the one of object
built. Change the clock of the computer from the first compile to the
second one may make it confused and so it can avoid to recompile source
that is changed.
About the kernel compile, I suggesto to copy your .config somewhere
safe, run "make mrproper" or "make clean" (first preferred), copy
.config again in /usr/src/linux and recompile.

OK, this was right on the money. I got distracted, delayed, and spent
hours reading kernel sources before I found my problem on a LMLBT4x
video grabber card. I corrected the time during a open 'make menuconfig'
session.....

Got things working nicely now.

James


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