than discard characters in the console daemon buffers.
New option: -o, --overflow-data=discard|keep
This option changes the behaviour when dealing with data that overflow
the max capacity of the buffer. If overflow-data is set to discard
(the default), the current behaviour is used: we discard some data in
the middle of the buffer.
If overflow-data is set to keep, we stop listening to the ring until
we free some space in the buffer. This can cause the ring to fill up
and the guest kernel internal buffer to fill up as well. When this
happens the guest kernel stops reading characters from the console
device so the application generating data hangs. When xenconsoled
resumes reading from the ring, the guest kernel will be able to resume
reading from the console device as well. At that point the guest
application will be allowed to continue.
The risk of making this behaviour the default is that existing kernel
drivers may assume they can rely on timely ring updates by the console
daemon and thus themselves block on the ring being emptied.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
* The --log command line argument takes one of 4 values
- none - no logging (the default)
- hv - log all hypervisor messages
- guest - log all guest messages
- both - log all guest & hypervisor messages
* The --log-dir command line argument takes a path to specify where
to store logfiles. If omitted it defaults to /var/log/xen/console
* The hypervisor logfile is $LOGDIR/hypervisor.log
* The guest logfile is $LOGDIR/guest-[NAME].log
* If receiving a SIGHUP it will close & re-open all log files to
enable logrotate to do its magic
* Fixes the permissions of /var/run/xenconsoled.pid
* Adds a --pid-file command line argument to override the default
location of pid file (this is not really related to logging, but
since I was in that code...)
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Keir Fraser
kfraser@localhost.localdomain
kaf24@firebug.cl.cam.ac.uk
vh249@arcadians.cl.cam.ac.uk
cl349@firebug.cl.cam.ac.uk