Re: Kernel ring buffer date stams missing
Be careful what you ask for. This is _not_ a true (time-of-day) timestamp. At least it wasn't last I looked. Think kernel active time since boot - useful for relative (timed) occurrences for kernel events. It would be reasonably trivial to adjust it to a ToD stamp, but it's going to have some holes in it. Shane ... On Sat, Apr 21st, 2012 at 6:28 PM, R P Herrold wrote: > Not just a hint -- the Red Hat kernel configuration appears > not to enable it -- but it may be trivially turned on: > > # echo 1 > /sys/module/printk/parameters/printk_time -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Kernel ring buffer date stams missing
On Fri, 20 Apr 2012, Aria Bamdad wrote:
by default on s390x. I also found some stuff online hinting that it is off
on Red Hat also.
Not just a hint -- the Red Hat kernel configuration appears
not to enable it -- but it may be trivially turned on:
# echo 1 > /sys/module/printk/parameters/printk_time
(note the slightly different parameter name than in the
article cited))
causes the addition of the time marks:
SCSI device sda: 1465149168 512-byte hdwr sectors (750156 MB)
sda: Write Protect is off
sda: Mode Sense: 00 3a 00 00
SCSI device sda: drive cache: write back
command run as root, and network restarted to get a
dmesg entry
[3243961.352381] ADDRCONF(NETDEV_UP): eth0: link is not ready
[3243962.098996] e1000: eth0 NIC Link is Up 100 Mbps Full
Duplex, Flow Control: RX/TX
[3243962.099073] ADDRCONF(NETDEV_CHANGE): eth0: link becomes
ready
[3243965.528690] ADDRCONF(NETDEV_UP): eth1: link is not ready
[3243967.715865] e1000: eth1 NIC Link is Up 1000 Mbps Full
Duplex, Flow Control: RX/TX
-- Russ herrold
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Re: Kernel ring buffer date stams missing
I see an old reference to a problem on ia64 architecture where turning on CONFIG_PRINTK_TIME causes problems at boot. Perhaps this is why it is off by default on s390x. I also found some stuff online hinting that it is off on Readhat also. Perhaps someone from SUSE can comment as to why. -Original Message- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of Christian Paro Sent: Friday, April 20, 2012 5:06 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: Kernel ring buffer date stams missing Of course, if you don't need the time stamps for early boot, you can turn them on at runtime through the /sys filesystem: http://elinux.org/Debugging_by_printing#Printk_Timestamps On Fri, Apr 20, 2012 at 4:57 PM, Christian Paro wrote: > Just a guess here, but maybe the s390x kernel for SLES 11 SP1 was compiled > with CONFIG_PRINTK_TIME disabled, while the x86-64 kernel had the same > option enabled? > > I do see those time-offset numbers at the beginning of output from other > kernels on s390x, so I don't think it's a difference inherent to the > architecture. > > > On Fri, Apr 20, 2012 at 4:40 PM, Aria Bamdad wrote: > >> Hi, >> >> >> >> Anyone knows why the kernel ring buffer (dmesg) is missing the usual time >> stamp prefix on each line on System z? For example: >> >> >> >> SUSE SLES 11 SP1 on system z shows this: >> >> >> >> Write protected kernel read-only data: 0x10 - 0x5f >> >> >> >> While Intel (same OS) shows: >> >> >> >> [1.611026] Write protecting the kernel read-only data: 8192k >> >> >> >> Thanks, >> >> Aria >> >> >> -- >> For LINUX-390 subscribe / signoff / archive access instructions, >> send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or >> visit >> http://www.marist.edu/htbin/wlvindex?LINUX-390 >> -- >> For more information on Linux on System z, visit >> http://wiki.linuxvm.org/ >> > > -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/ -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Kernel ring buffer date stams missing
Of course, if you don't need the time stamps for early boot, you can turn them on at runtime through the /sys filesystem: http://elinux.org/Debugging_by_printing#Printk_Timestamps On Fri, Apr 20, 2012 at 4:57 PM, Christian Paro wrote: > Just a guess here, but maybe the s390x kernel for SLES 11 SP1 was compiled > with CONFIG_PRINTK_TIME disabled, while the x86-64 kernel had the same > option enabled? > > I do see those time-offset numbers at the beginning of output from other > kernels on s390x, so I don't think it's a difference inherent to the > architecture. > > > On Fri, Apr 20, 2012 at 4:40 PM, Aria Bamdad wrote: > >> Hi, >> >> >> >> Anyone knows why the kernel ring buffer (dmesg) is missing the usual time >> stamp prefix on each line on System z? For example: >> >> >> >> SUSE SLES 11 SP1 on system z shows this: >> >> >> >> Write protected kernel read-only data: 0x10 - 0x5f >> >> >> >> While Intel (same OS) shows: >> >> >> >> [1.611026] Write protecting the kernel read-only data: 8192k >> >> >> >> Thanks, >> >> Aria >> >> >> -- >> For LINUX-390 subscribe / signoff / archive access instructions, >> send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or >> visit >> http://www.marist.edu/htbin/wlvindex?LINUX-390 >> -- >> For more information on Linux on System z, visit >> http://wiki.linuxvm.org/ >> > > -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Re: Kernel ring buffer date stams missing
Just a guess here, but maybe the s390x kernel for SLES 11 SP1 was compiled with CONFIG_PRINTK_TIME disabled, while the x86-64 kernel had the same option enabled? I do see those time-offset numbers at the beginning of output from other kernels on s390x, so I don't think it's a difference inherent to the architecture. On Fri, Apr 20, 2012 at 4:40 PM, Aria Bamdad wrote: > Hi, > > > > Anyone knows why the kernel ring buffer (dmesg) is missing the usual time > stamp prefix on each line on System z? For example: > > > > SUSE SLES 11 SP1 on system z shows this: > > > > Write protected kernel read-only data: 0x10 - 0x5f > > > > While Intel (same OS) shows: > > > > [1.611026] Write protecting the kernel read-only data: 8192k > > > > Thanks, > > Aria > > > -- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or > visit > http://www.marist.edu/htbin/wlvindex?LINUX-390 > -- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
Kernel ring buffer date stams missing
Hi, Anyone knows why the kernel ring buffer (dmesg) is missing the usual time stamp prefix on each line on System z? For example: SUSE SLES 11 SP1 on system z shows this: Write protected kernel read-only data: 0x10 - 0x5f While Intel (same OS) shows: [1.611026] Write protecting the kernel read-only data: 8192k Thanks, Aria -- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 -- For more information on Linux on System z, visit http://wiki.linuxvm.org/
