From: Roger Pau Monne Date: Tue, 12 Feb 2013 12:47:28 +0000 (+0100) Subject: xen-blkback: don't store dev_bus_addr X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=5079e5caaaa6b59f89079f2a4d317886cef4dea3;p=people%2Froyger%2Flinux.git xen-blkback: don't store dev_bus_addr dev_bus_addr returned in the grant ref map operation is the mfn of the passed page, there's no need to store it in the persistent grant entry, since we can always get it provided that we have the page. This reduces the memory overhead of persistent grants in blkback. Signed-off-by: Roger Pau Monné Cc: Konrad Rzeszutek Wilk Cc: xen-devel@lists.xen.org --- diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index de1f319f7bd7..d40beb39bf90 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -621,9 +621,7 @@ static int xen_blkbk_map(struct blkif_request *req, * If this is a new persistent grant * save the handler */ - persistent_gnts[i]->handle = map[j].handle; - persistent_gnts[i]->dev_bus_addr = - map[j++].dev_bus_addr; + persistent_gnts[i]->handle = map[j++].handle; } pending_handle(pending_req, i) = persistent_gnts[i]->handle; @@ -631,7 +629,8 @@ static int xen_blkbk_map(struct blkif_request *req, if (ret) continue; - seg[i].buf = persistent_gnts[i]->dev_bus_addr | + seg[i].buf = pfn_to_mfn(page_to_pfn( + persistent_gnts[i]->page)) << PAGE_SHIFT | (req->u.rw.seg[i].first_sect << 9); } else { pending_handle(pending_req, i) = map[j].handle; diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index 6072390c7f57..f338f8a083ad 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -172,7 +172,6 @@ struct persistent_gnt { struct page *page; grant_ref_t gnt; grant_handle_t handle; - uint64_t dev_bus_addr; struct rb_node node; };