Re: [RFC v5 0/3] migration: reduce time of loading non-iterable vmstate

[Peter Xu]

On Wed, Feb 22, 2023 at 02:27:55PM +0800, Chuang Xu wrote:
> Hi, Peter

Hi, Chuang,

> Note that as I mentioned in the comment, we temporarily replace this value
> to prevent commit() and address_space_to_flatview() call each other 
> recursively,
> and eventually stack overflow.

Sorry to have overlooked that part.  IMHO here it's not about the depth,
but rather that we don't even need any RCU protection when updating
ioeventfds because we exclusively own the FlatView* too there.

I wanted to describe what I had in mind but instead I figured a patch may
be needed to be accurate (with some cleanups alongside), hence attached.
IIUC it can work with what I suggested before without fiddling with depth.
Please have a look.  The patch should apply cleanly to master branch so if
it works it can be your 1st patch too.

PS: Paolo - I know I asked this before, but it'll be good to have your
review comment on anything above.

Thanks,

-- 
Peter Xu

0001-memory-Reference-current_map-directly-in-ioeventfd-u.patch
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