| Date | Thu, 28 Feb 2013 11:07:25 +0000 | From | "Jan Beulich" <> | Subject | Re: [Xen-devel] [PATCH RFC 09/12] xen-blkback: move pending handles list from blkbk to pending_req |
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>>> On 28.02.13 at 11:28, Roger Pau Monne <roger.pau@citrix.com> wrote: > Moving grant ref handles from blkbk to pending_req will allow us to > get rid of the shared blkbk structure.
At the expense of (slightly?) higher memory requirements?
> --- a/drivers/block/xen-blkback/blkback.c > +++ b/drivers/block/xen-blkback/blkback.c > @@ -136,6 +136,7 @@ struct pending_req { > struct list_head free_list; > struct persistent_gnt *persistent_gnts[BLKIF_MAX_SEGMENTS_PER_REQUEST]; > struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST]; > + grant_handle_t grant_handles[BLKIF_MAX_SEGMENTS_PER_REQUEST];
Adding yet another array here makes it even more desirable to switch from multiple arrays to a singly array of a structure, thus improving locality of the memory accesses involved in processing an individual segment.
Jan
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