Re: [Xen-devel] [PATCH v3 0/5] xen/blk: persistent grant rework

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Mon, Aug 13, 2018 at 04:01:09PM +0200, Juergen Gross wrote:
> Persistent grants are used in the Xen's blkfront/blkback drivers to
> avoid mapping/unmapping of I/O buffers in the backend for each I/O.
> 
> While this speeds up processing quite a bit there are problems related
> to persistent grants in some configurations: domains with multiple
> block devices making use of persistent grants might suffer from a lack
> of grants if each of the block devices experienced a high I/O load at
> some time. This is due to the number of persistent grants per device
> only to be limited by a rather high maximum value, but never being
> released even in case of longer times without any I/O.
> 
> This series modifies xen-blkback to unmap any domU page mapped via a
> persistent grant after a timeout (default: 60 seconds). The timeout
> is set to its default value again when a persistent grant has been
> used for an I/O.
> 
> xen-blkfront is modified to scan every 10 seconds for persistent grants
> not in use by blkback any more and to remove such grants.
> 
> The last 3 patches are small cleanups of blkfront and blkback drivers.
> 
> V3:
> - patch 1: make timeout parameter static

Konrad if you are OK with this series, could you please send a pull
request to Jens?

Thanks, Roger.

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel