File kgr.man of Package kgraft

.\" Libor Pechacek <lpechacek@suse.com>
.\"
.TH KGR 8 2014-10-02 "SLES 12" "SLE Live Patching"
.SH NAME
kgr \- query and manipulate kGraft patching status
.SH SYNOPSIS
.ll +8
.B kgr
.RB [ " \-hv " ]
.RI COMMAND
.ll -8
.SH DESCRIPTION
.I kgr
command can be used for getting a quick overview of the kGraft patching status.
Also it can poke blocking processes and move forward with the patching.
For some of the commands, the output can be made more verbose by using
.B \-v
option.
.SH COMMANDS
.TP
.B status
Display the overall status of kGraft patching (ready or in_progress)
.TP
.B patches
Display the list of loaded patches
.TP
.B blocking
List processes that are preventing kGraft patching from finishing.  By default just the PIDs are listed.  Specifying
.B \-v
will make
.I kgr
print out the command line.  Another
.B \-v
will display also strack traces.
.TP
.B poke
Send STOP and CONT signals to processess that are blocking kGraft progress.  See 
.SM
.B CAVEATS
for discussion about this method.
.SH OPTIONS
.TP
.B \-h --help
Display a help screen and quit.
.TP
.B \-v --verbose
Verbose.  With
.B blocking
command makes
.I kgr
print out process command line.
Another
.B \-v
will display also strack traces.
.TP
.B \--version
Version. Display the version number.
.SH CAVEATS
By design, kGraft technology requires the processes to cross the user
space/kernel boundary to present them with the patched kernel code.  Processes
that sleep in kernel code at the time the patch module is loaded will prevent
patching process from finishing until they leave kernel space.  These processes
usually leave kernel after the event, for which they are waiting, happens or
timeout elapses.
.P
Sending regular processes STOP signal followed by CONT signal achieves the
goal of making them to cross the user space/kernel boundary immediately.  However, this
method may not be suitable for all processes runing in the system and does not
apply to kernel threads and processess in
.B D
process state.