Re: [Devel] Re: [PATCH 08/10] Introduce functions to restart aprocess

[Greg Kurz]

On Wed, 2008-10-22 at 11:25 +0200, Louis Rilling wrote:
> Do you checkpoint uninterruptible syscalls as well? If only interruptible
> syscalls are checkpointed, I'd say that either this syscall uses ERESTARTSYS or
> ERESTART_RESTARTBLOCK, and then signal handling code already does the trick, or
> this syscall does not restart itself when interrupted, and well, this is life,
> userspace just sees -EINTR, which is allowed by the syscall spec.
> Actually this is how we checkpoint/migrate tasks in interruptible syscalls in
> Kerrighed and this works.
> 
> Louis
> 

I don't know Kerrighed internals but I understand you perform checkpoint
with a signal handler. Right ? This approach has a huge benefit: the
signal handling code do all the arch dependant stuff to save registers
in user memory.

-- 
Gregory Kurz                                     gkurz@xxxxxxxxxx
Software Engineer @ IBM/Meiosys                  http://www.ibm.com
Tel +33 (0)534 638 479                           Fax +33 (0)561 400 420

"Anarchy is about taking complete responsibility for yourself."
        Alan Moore.

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