X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fmd%2Fxor.c;h=324897c4be4ed04cac7404f008cf17ca0c0f5dbc;hb=9bf4aaab3e101692164d49b7ca357651eb691cb6;hp=e2103a8bb75a0ecc8ce76cc9054118bc18e9fc34;hpb=db216c3d5e4c040e557a50f8f5d35d5c415e8c1c;p=linux-2.6.git

diff --git a/drivers/md/xor.c b/drivers/md/xor.c
index e2103a8bb..324897c4b 100644
--- a/drivers/md/xor.c
+++ b/drivers/md/xor.c
@@ -108,29 +108,40 @@ calibrate_xor_block(void)
 	}
 	b2 = b1 + 2*PAGE_SIZE + BENCH_SIZE;
 
-	printk(KERN_INFO "raid5: measuring checksumming speed\n");
+	/*
+	 * If this arch/cpu has a short-circuited selection, don't loop through 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)
 
-	XOR_TRY_TEMPLATES;
+	if (fastest) {
+		printk(KERN_INFO "raid5: automatically using best checksumming function: %s\n",
+			fastest->name);
+		xor_speed(fastest);
+	} else {
+		printk(KERN_INFO "raid5: measuring checksumming speed\n");
+		XOR_TRY_TEMPLATES;
+		fastest = template_list;
+		for (f = fastest; f; f = f->next)
+			if (f->speed > fastest->speed)
+				fastest = f;
+	}
+
+	printk("raid5: using function: %s (%d.%03d MB/sec)\n",
+	       fastest->name, fastest->speed / 1000, fastest->speed % 1000);
 
 #undef xor_speed
 
 	free_pages((unsigned long)b1, 2);
 
-	fastest = template_list;
-	for (f = fastest; f; f = f->next)
-		if (f->speed > fastest->speed)
-			fastest = f;
-
-#ifdef XOR_SELECT_TEMPLATE
-	fastest = XOR_SELECT_TEMPLATE(fastest);
-#endif
-
 	active_template = fastest;
-	printk("raid5: using function: %s (%d.%03d MB/sec)\n",
-	       fastest->name, fastest->speed / 1000, fastest->speed % 1000);
-
 	return 0;
 }