SysRQ over serial console redirects to syslog

[[e-mail]]

VERSION="13.10, Saucy Salamander"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 13.10"
VERSION_ID="13.10"

vmlinux-3.11.0-5-powerpc-e500mc

When SysRQ is enabled through /proc :

  echo 1 > /proc/sys/kernel/sysrq

All responses from SysRQ sequences are redirected to /var/log/syslog , not the serial console.

For instance:

 SySRQ ( break ) l

Is suppose to report CPU stack traces . The summary is sent to v/var/log/syslog , not the serial port, which
defeats the entire purpose of SysRQ feature which is intended for diagnostics of server issues.

The logging behavior can redirected to the console by using :

 dmesg --console-on

This should be the default behavior for ppc ; It is also how x86 has worked in the past.

[Ben Collins (ben-collins)]

John,

This isn't a bug. You are normally booted in Linux with the "quiet" flag passed to the kernel command line. You won't see output like this unless you either boot without that flag, or run a command such as "dmesg --console-on" or twiddle some bits in /proc/sys/kernel/printk.

This is normal behavior.

[[e-mail] (john-d-0)]

I know it's not a "bug" per say .

On Sat, Mar 8, 2014 at 8:21 AM, Ben Collins <email address hidden> wrote:

> John,
>
> This isn't a bug. You are normally booted in Linux with the "quiet" flag
> passed to the kernel command line. You won't see output like this unless
> you either boot without that flag, or run a command such as "dmesg
> --console-on" or twiddle some bits in /proc/sys/kernel/printk.
>
> This is normal behavior.
>
> ** Changed in: linux-ppc (Ubuntu)
> Status: New => Invalid
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1282201
>
> Title:
> SysRQ over serial console redirects to syslog
>
> Status in "linux-ppc" package in Ubuntu:
> Invalid
>
> Bug description:
>
> VERSION="13.10, Saucy Salamander"
> ID=ubuntu
> ID_LIKE=debian
> PRETTY_NAME="Ubuntu 13.10"
> VERSION_ID="13.10"
>
> vmlinux-3.11.0-5-powerpc-e500mc
>
>
> When SysRQ is enabled through /proc :
>
>
> echo 1 > /proc/sys/kernel/sysrq
>
>
> All responses from SysRQ sequences are redirected to /var/log/syslog ,
> not the serial console.
>
> For instance:
>
> SySRQ ( break ) l
>
> Is suppose to report CPU stack traces . The summary is sent to
> v/var/log/syslog , not the serial port, which
> defeats the entire purpose of SysRQ feature which is intended for
> diagnostics of server issues.
>
> The logging behavior can redirected to the console by using :
>
> dmesg --console-on
>
> This should be the default behavior for ppc ; It is also how x86 has
> worked in the past.
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/linux-ppc/+bug/1282201/+subscriptions
>

--

*Regards,*
* John.*

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