eliminate direct assignments of CPU masks

Use cpumask_copy() instead of direct variable assignments for copying
CPU masks. While direct assignments are not a problem when both sides
are variables actually defined as cpumask_t (except for possibly
copying *much* more than would actually need to be copied), they must
not happen when the original variable is of type cpumask_var_t (which
may have lass space allocated to it than a full cpumask_t). Eliminate
as many of such assignments as possible (in several cases it's even
possible to collapse two operations [copy then clear one bit] into one
[cpumask_andnot()]), and thus set the way for reducing the allocation
size in alloc_cpumask_var().

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 95a1116f84..a01698beb2 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -267,7 +267,8 @@ static void set_cpu_sibling_map(int cpu)
 
     if ( c[cpu].x86_max_cores == 1 )
     {
-        per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
+        cpumask_copy(&per_cpu(cpu_core_map, cpu),
+                     &per_cpu(cpu_sibling_map, cpu));
         c[cpu].booted_cores = 1;
         return;
     }