crypto: xor - skip speed test if the xor function is selected automatically

If the architecture selected the xor function with XOR_SELECT_TEMPLATE
the speed result of the do_xor_speed benchmark is of limited value.
The speed measurement increases the bootup time a little, which can
makes a difference for kernels used in container like virtual machines.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 19 insertions, 21 deletions

diff --git a/crypto/xor.c b/crypto/xor.c
index 35d6b3adf230..b8975d92cd94 100644
--- a/crypto/xor.c
+++ b/crypto/xor.c
@@ -109,6 +109,18 @@ calibrate_xor_blocks(void)
         void *b1, *b2;
         struct xor_block_template *f, *fastest;
 
+        fastest = NULL;
+
+#ifdef XOR_SELECT_TEMPLATE
+        fastest = XOR_SELECT_TEMPLATE(fastest);
+        if (fastest) {
+                printk(KERN_INFO "xor: automatically using best "
+                                 "checksumming function   %-10s\n",
+                       fastest->name);
+                goto out;
+        }
+#endif
+
         /*
          * Note: Since the memory is not actually used for _anything_ but to
          * test the XOR speed, we don't really want kmemcheck to warn about
@@ -126,36 +138,22 @@ calibrate_xor_blocks(void)
          * all the possible functions, just test the best one
          */
 
-        fastest = NULL;
-
-#ifdef XOR_SELECT_TEMPLATE
-                fastest = XOR_SELECT_TEMPLATE(fastest);
-#endif
-
 #define xor_speed(templ)        do_xor_speed((templ), b1, b2)
 
-        if (fastest) {
-                printk(KERN_INFO "xor: automatically using best "
-                                 "checksumming function:\n");
-                xor_speed(fastest);
-                goto out;
-        } else {
-                printk(KERN_INFO "xor: measuring software checksum speed\n");
-                XOR_TRY_TEMPLATES;
-                fastest = template_list;
-                for (f = fastest; f; f = f->next)
-                        if (f->speed > fastest->speed)
-                                fastest = f;
-        }
+        printk(KERN_INFO "xor: measuring software checksum speed\n");
+        XOR_TRY_TEMPLATES;
+        fastest = template_list;
+        for (f = fastest; f; f = f->next)
+                if (f->speed > fastest->speed)
+                        fastest = f;
 
         printk(KERN_INFO "xor: using function: %s (%d.%03d MB/sec)\n",
                fastest->name, fastest->speed / 1000, fastest->speed % 1000);
 
 #undef xor_speed
 
- out:
         free_pages((unsigned long)b1, 2);
-
+out:
         active_template = fastest;
         return 0;
 }