Messages in this thread | | | Date | Fri, 24 Jan 2014 14:44:21 +0000 | From | David Vrabel <> | Subject | Re: [Xen-devel] [PATCH v5] xen/grant-table: Avoid m2p_override during mapping |
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On 24/01/14 14:37, Konrad Rzeszutek Wilk wrote: > On Thu, Jan 23, 2014 at 01:07:10PM +0000, Zoltan Kiss 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, as >> those pages never go to userspace. Therefore this series does the following: >> - the original functions were renamed to __gnttab_[un]map_refs, with a new >> 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 with >> m2p_override false >> - a new function gnttab_[un]map_refs_userspace provides the old behaviour >> >> It also removes a stray space from page.h and change ret to 0 if >> XENFEAT_auto_translated_physmap, as that is the only possible return value >> there. >> >> v2: >> - move the storing of the old mfn in page->index to gnttab_map_refs >> - move the function header update to a separate patch >> >> v3: >> - a new approach to retain old behaviour where it needed >> - squash the patches into one >> >> v4: >> - move out the common bits from m2p* functions, and pass pfn/mfn as parameter >> - clear page->private before doing anything with the page, so m2p_find_override >> won't race with this >> >> v5: >> - change return value handling in __gnttab_[un]map_refs >> - remove a stray space in page.h >> - add detail why ret = 0 now at some places >> >> Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com> >> Suggested-by: David Vrabel <david.vrabel@citrix.com> > > It looks OK to me and while it is not a bug-fix I think it should > go for v3.14 - as it _should_ improve the backends. > > David or Boris; Stefano, please Ack/Nack it.
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
David
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