Re: [Xen-devel] [PATCH v3] xen/grant-table: Avoid m2p_override duringmapping

From: Zoltan Kiss
Date: Thu Jan 23 2014 - 08:06:19 EST

On 20/01/14 21:22, Konrad Rzeszutek Wilk wrote:
Zoltan Kiss <zoltan.kiss@xxxxxxxxxx> wrote:
The grant mapping API does m2p_override unnecessarily: only gntdev
needs it,
for blkback and future netback patches it just cause a lock contention,
those pages never go to userspace. Therefore this series does the
- the original functions were renamed to __gnttab_[un]map_refs, with a
parameter m2p_override
- based on m2p_override either they follow the original behaviour, or
just set
the private flag and call set_phys_to_machine
- gnttab_[un]map_refs are now a wrapper to call __gnttab_[un]map_refs
m2p_override false
- a new function gnttab_[un]map_refs_userspace provides the old

You don't say anything about the 'return ret' changed to 'return 0'.

Any particular reason for that?

That's the only possible return value there, so it just makes it more obvious. I'll add a description about that.


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