Hitachi djprobe mechanism

[Keshavamurthy, Anil S]

>It's OK for probe insertion to be slow. 

Yes, slow is okay as long as you are *not* taking the full 
system down during probe inserting/removal time. Halting full 
system during probe insertion/removal might not be acceptable 
at least on IA64.

>So why not use RCU to 
>synchronize
>other processors?

The thing here is while we are trying to modify the section of code say 
couple of instructions to accommodate 5 bytes(jmp inst), during this
period 
we don't want any cpu to be in the middle of this area and to be
*really* 
sure they(other CPU's) don't get half backed instruction, we must 
place all of the other CPU's in a known location. So in this scenario, 
I doubt how  RCU synchronization can help. 

If I am wrong please educate me.


Cheers,
-Anil