[PATCH 5/5] xen-blkfront: remove frame list from blk_shadow

Roger Pau Monne
2013-03-18T16:51:48Z

We already have the frame (pfn of the grant page) stored inside struct
grant, so there's no need to keep an aditional list of mapped frames
for a specific request. This reduces memory usage in blkfront.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: xen-devel@lists.xen.org
---
drivers/block/xen-blkfront.c | 6 +-----
1 files changed, 1 insertions(+), 5 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index c640433..a894f88 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -74,7 +74,6 @@ struct grant {
struct blk_shadow {
struct blkif_request req;
struct request *request;
- unsigned long frame[BLKIF_MAX_SEGMENTS_PER_REQUEST];
struct grant *grants_used[BLKIF_MAX_SEGMENTS_PER_REQUEST];
};

@@ -356,7 +355,6 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
static int blkif_queue_request(struct request *req)
{
struct blkfront_info *info = req->rq_disk->private_data;
- unsigned long buffer_mfn;
struct blkif_request *ring_req;
unsigned long id;
unsigned int fsect, lsect;
@@ -434,7 +432,6 @@ static int blkif_queue_request(struct request *req)

gnt_list_entry = get_grant(&gref_head, info);
ref = gnt_list_entry->gref;
- buffer_mfn = pfn_to_mfn(gnt_list_entry->pfn);

info->shadow[id].grants_used[i] = gnt_list_entry;

@@ -465,7 +462,6 @@ static int blkif_queue_request(struct request *req)
kunmap_atomic(shared_data);
}

- info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn);
ring_req->u.rw.seg[i] =
(struct blkif_request_segment) {
.gref = ref,
@@ -1268,7 +1264,7 @@ static int blkif_recover(struct blkfront_info *info)
gnttab_grant_foreign_access_ref(
req->u.rw.seg[j].gref,
info->xbdev->otherend_id,
- pfn_to_mfn(info->shadow[req->u.rw.id].frame[j]),
+ pfn_to_mfn(copy[i].grants_used[j]->pfn),
0);
}
info->shadow[req->u.rw.id].req = *req;
--
1.7.7.5 (Apple Git-26)