[Xen-devel] [PATCH 1 of 2] x86/mem_sharing: Fix saved mfns stat for failed unsharing

[Andres Lagar-Cavilla <andres@xxxxxxxxxxxxxxxx>]

 xen/arch/x86/mm/mem_sharing.c |  2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)


If unsharing fails, the decrease of the nr_saved_mfns stat was not being
undone. This would result in an underflow of the stat, as the retry would later
decrease the counter again.

Signed-off-by: Andres Lagar-Cavilla <andres@xxxxxxxxxxxxxxxx>

diff -r 8a6f6d38cb84 -r 5be9a05f17fd xen/arch/x86/mm/mem_sharing.c
--- a/xen/arch/x86/mm/mem_sharing.c
+++ b/xen/arch/x86/mm/mem_sharing.c
@@ -1205,6 +1205,8 @@ int __mem_sharing_unshare_page(struct do
     page = alloc_domheap_page(d, 0);
     if ( !page ) 
     {
+        /* Undo dec of nr_saved_mfns, as the retry will decrease again. */
+        atomic_inc(&nr_saved_mfns);
         mem_sharing_page_unlock(old_page);
         put_gfn(d, gfn);
         /* Caller is responsible for placing an event

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel