| Date | Thu, 28 Feb 2013 10:49:11 +0000 | From | "Jan Beulich" <> | Subject | Re: [Xen-devel] [PATCH RFC 00/12] xen-block: indirect descriptors |
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>>> On 28.02.13 at 11:28, Roger Pau Monne <roger.pau@citrix.com> wrote: > This series contains the initial implementation of indirect > descriptors for Linux blkback/blkfront. > > Patches 1, 2, 3, 4 and 5 are bug fixes and minor optimizations. > > Patch 6 contains a LRU implementation for blkback that will be needed > when using indirect descriptors (since we are no longer able to map > all possible grants blkfront might use).
Considering this, ...
> Patch 7 is an addition to the print stats function in blkback in order > to print information regarding persistent grant usage. > > Patches 8, 9, 10 and 11 are preparatory work for indirect descriptors > implementation, mainly make blkback use dynamic memory and remove the > shared blkbk structure, so each blkback instance has it's own list of > free requests, pages, handles and so on. > > Finally patch 12 contains the indirect descriptors implementation. > > I've also pushed this series to the following git repository: > > git://xenbits.xen.org/people/royger/linux.git xen-block-indirect > > Performance benefit of this series can be seen in the following graph: > > http://xenbits.xen.org/people/royger/plot_indirect.png
... would you happen to also have a comparison with using indirect descriptors but not persistent grants? IOW I'm wondering about the hit rate on the persistently mapped grants, especially when blkfront really saturates the added bandwidth.
Jan
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