[SSI] What happens when the second node boots [ correct me if i am wrong ]

[Aneesh K. K.V <ane...@di...>]

Hi, 

 While debugging the crash on alpha I tried to trace the calls  when the
second node joins. I am putting below what i noticed .I may be wrong at
some of the places. So please correct me. I guess this should be helpful
when SSI get taken to some other platform. 



What happens when the second node boots and join the cluster .....


When the second node boots and tries to join the cluster  it makes a
call to cluster_config --intiproc( Done inside /linuxrc which resides in
the inital ramdisk ). The  cluster_config further goes to  make a system
call ( The generic system call ssisys which is mapped to the kernel
call   sys_ssisys ). It further goes down to make a call to  
initproc_postroot which resides inthe file nsc_initproc.c  This call
further goes down and sleeps for ever.

cluster_config --initproc 

enter the kernel 
sys_ssisys 
initproc_postroot
sleep 



 Meanwhile the init in the master node is notified regarding the arrival
of the new node. I don't know how it is notified. I guess through the
SIGCLUSTER  with the node number( Correct me if I am wrong ) . Here it
scans the /etc/inittab.ssi. and start all the lines mareked U/D/R/L .
For the time being we have only U for rc.nodeup and D for  rc.nodedown.
Since we are here during node up   it goes and execute rc.nodeup .

The entire call goes down from process_node to  _startup and then to
_spawn  it further check if the node is same at his node number if not
it makes a call to rexecvp which is implemented in libcluster. It
further goes making a call __rexecve which then make a system call to
rexecve  The sys_rexecve will then go and make cli_rexecve  call .


_startup

_spawn
if( node !== this_node )
	rexecvp
	__rexecve
	sys_rexecve
	cli_rexecve

	
 
-aneesh