PIDs in Checkpoint/Restart

From: Heiko Bauke (heiko.bauke_at_physik.uni-magdeburg.de)
Date: Tue Mar 08 2005 - 11:55:32 PST

  • Next message: jcduell_at_lbl_dot_gov: "Re: PIDs in Checkpoint/Restart"
    Dear BLCR developer,
    
    the BLCR web page claims: BLCR restores the process ID (PID), thread
    group ID (TGID), parent process ID (PPID), and process tree to old
    state.
    
    How does this work? Is this feature reliable?
    
    Under Linux a PID is less than 2^31 and PIDs may be recycled. So let's
    consider the following situation. A program with a PID of 42 was
    checkpointed and suspended. Because the process is stopped, his PID may
    be recycled. So what will happen, when BLCR restarts the suspended
    process but its former PID 42 is now owned by another process?
    
    
    	with regards
    
    	Heiko
    
    -- 
    -- Toleranz heißt: die Fehler der anderen entschuldigen. Takt heißt: sie
    -- nicht bemerken. (Arthur Schnitzler)
    -- Supercomputing in Magdeburg @ http://tina.nat.uni-magdeburg.de
    --                 Heiko Bauke @ http://www.uni-magdeburg.de/bauke
    

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