From: Steven Smith <ssmith@weybridge.uk.xensource.com>
Date: Thu, 16 Apr 2009 13:30:37 +0000 (+0100)
Subject: Slightly nicer way of checking whether a page is currently tracked.
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=3cedc3fdab00f0858170e7715aa527cdce5cb74f;p=people%2Fssmith%2Fnetchannel2-pvops.bak.git%2F.git

Slightly nicer way of checking whether a page is currently tracked.
---

diff --git a/drivers/xen/netback/netback.c b/drivers/xen/netback/netback.c
index 2ea96223954..91063190ffc 100644
--- a/drivers/xen/netback/netback.c
+++ b/drivers/xen/netback/netback.c
@@ -303,7 +303,7 @@ static u16 netbk_gop_frag(struct xen_netif *netif, struct netbk_rx_meta *meta,
 
 	copy_gop = npo->copy + npo->copy_prod++;
 	copy_gop->flags = GNTCOPY_dest_gref;
-	if (PageForeign(page) && page->mapping != NULL) {
+	if (page_is_tracked(page)) {
 		lookup_tracker_page(page, &copy_gop->source.domid,
 				    &copy_gop->source.u.ref);
 		copy_gop->flags |= GNTCOPY_source_gref;
diff --git a/include/xen/live_maps.h b/include/xen/live_maps.h
index 130e151a3fb..f35b6325a16 100644
--- a/include/xen/live_maps.h
+++ b/include/xen/live_maps.h
@@ -135,4 +135,9 @@ static inline void lookup_tracker_page(struct page *p, domid_t *dom,
         *gref = pft->contents[idx & LIVE_MAP_TRACKER_IDX_MASK].gref;
 }
 
+static inline int page_is_tracked(struct page *p)
+{
+	return PageForeign(p) && p->mapping;
+}
+
 #endif /* !XEN_LIVE_MAPS_H__ */