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From: Dave Hansen <dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
To: containers <containers-qjLDD68F18O7TbgM5vRIOg@public.gmane.org>
Cc: Ingo Molnar <mingo-X9Un+BFzKDI@public.gmane.org>,
	Nathan Lynch <nathanl-V7BBcbaFuwjMbYB6QlFGEg@public.gmane.org>,
	Alexey Dobriyan
	<adobriyan-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
Subject: thoughts on checkpointing /proc/mounts
Date: Mon, 02 Mar 2009 10:48:39 -0800	[thread overview]
Message-ID: <1236019719.26788.505.camel@nimitz> (raw)

Christoph's suggestion that we go add f_ops individually is a really
good way to get people thinking about individual cases that we have to
deal with.

Can we checkpoint an *open* /proc/mounts?  I don't think we want to.  It
could get really nasty really fast.  But, what if the f_pos is 0?  That
makes it a lot easier.

If the "may checkpoint" flag is per-container (as Alexey has said) and
one-way (as Ingo has said), does a single 'cat /proc/mounts' 5 days ago
keep a container from being checkpointed today?

I just don't think the container-wide flag works if it is one way.

I think making it per-process or per-resource (so it can be more easily
tracked at fork()/clone()/exec()) is the only way to go.  It makes it so
simple since only the 'cat /proc/mounts' process becomes
uncheckpointable.  Once it exits, we are OK and can checkpoint again.
That all seems right to me. 

-- Dave

             reply	other threads:[~2009-03-02 18:48 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-02 18:48 Dave Hansen [this message]
2009-03-02 19:43 ` thoughts on checkpointing /proc/mounts Serge E. Hallyn

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