[Xen-changelog] [xen master] x86/shadow: remove pointless loops over all vCPU-s

[patchbot@xxxxxxx]

commit b8c7758ce299d95e6791232809654a98472974a4
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Dec 20 10:04:48 2017 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Dec 20 10:04:48 2017 +0100

    x86/shadow: remove pointless loops over all vCPU-s
    
    The vCPU count can be had more directly.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Tim Deegan <tim@xxxxxxx>
---
 xen/arch/x86/mm/shadow/common.c | 8 +-------
 xen/arch/x86/mm/shadow/multi.c  | 8 +++-----
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 3a33e0b..600df0c 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -1143,13 +1143,7 @@ const u8 sh_type_to_size[] = {
  * worth to make sure we never return zero. */
 static unsigned int shadow_min_acceptable_pages(struct domain *d)
 {
-    u32 vcpu_count = 1;
-    struct vcpu *v;
-
-    for_each_vcpu(d, v)
-        vcpu_count++;
-
-    return (vcpu_count * 128);
+    return (d->max_vcpus + 1) * 128;
 }
 
 /* Dispatcher function: call the per-mode function that will unhook the
diff --git a/xen/arch/x86/mm/shadow/multi.c b/xen/arch/x86/mm/shadow/multi.c
index 4408575..f7182e4 100644
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -1476,16 +1476,14 @@ sh_make_shadow(struct vcpu *v, mfn_t gmfn, u32 
shadow_type)
          * pinning l3es.  This is not very quick but it doesn't happen
          * very often. */
         struct page_info *sp, *t;
-        struct vcpu *v2;
-        int l4count = 0, vcpus = 0;
+        unsigned int l4count = 0;
+
         page_list_for_each(sp, &d->arch.paging.shadow.pinned_shadows)
         {
             if ( sp->u.sh.type == SH_type_l4_64_shadow )
                 l4count++;
         }
-        for_each_vcpu ( d, v2 )
-            vcpus++;
-        if ( l4count > 2 * vcpus )
+        if ( l4count > 2 * d->max_vcpus )
         {
             /* Unpin all the pinned l3 tables, and don't pin any more. */
             page_list_for_each_safe(sp, t, 
&d->arch.paging.shadow.pinned_shadows)
--
generated by git-patchbot for /home/xen/git/xen.git#master

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