lib/test_bitmap.c: add optimisation tests

Patch series "Bitmap optimisations", v2.

These three bitmap patches use more efficient specialisations when the
compiler can figure out that it's safe to do so.  Thanks to Rasmus's
eagle eyes, a nasty bug in v1 was avoided, and I've added a test case
which would have caught it.

This patch (of 4):

This version of the test is actually a no-op; the next patch will enable
it.

Link: http://lkml.kernel.org/r/20170628153221.11322-2-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index e2cbd43d193cff9de5e92f5a7e85fd9f53790210..252d3bddbe7de47e9c245f9fee07b99bec523c7c 100644 (file)
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -333,10 +333,42 @@ static void __init test_bitmap_u32_array_conversions(void)
        }
 }
 
+#define __bitmap_set(a, b, c)  bitmap_set(a, b, c)
+#define __bitmap_clear(a, b, c)        bitmap_clear(a, b, c)
+
+static void noinline __init test_mem_optimisations(void)
+{
+       DECLARE_BITMAP(bmap1, 1024);
+       DECLARE_BITMAP(bmap2, 1024);
+       unsigned int start, nbits;
+
+       for (start = 0; start < 1024; start += 8) {
+               memset(bmap1, 0x5a, sizeof(bmap1));
+               memset(bmap2, 0x5a, sizeof(bmap2));
+               for (nbits = 0; nbits < 1024 - start; nbits += 8) {
+                       bitmap_set(bmap1, start, nbits);
+                       __bitmap_set(bmap2, start, nbits);
+                       if (!bitmap_equal(bmap1, bmap2, 1024))
+                               printk("set not equal %d %d\n", start, nbits);
+                       if (!__bitmap_equal(bmap1, bmap2, 1024))
+                               printk("set not __equal %d %d\n", start, nbits);
+
+                       bitmap_clear(bmap1, start, nbits);
+                       __bitmap_clear(bmap2, start, nbits);
+                       if (!bitmap_equal(bmap1, bmap2, 1024))
+                               printk("clear not equal %d %d\n", start, nbits);
+                       if (!__bitmap_equal(bmap1, bmap2, 1024))
+                               printk("clear not __equal %d %d\n", start,
+                                                                       nbits);
+               }
+       }
+}
+
 static int __init test_bitmap_init(void)
 {
        test_zero_fill_copy();
        test_bitmap_u32_array_conversions();
+       test_mem_optimisations();
 
        if (failed_tests == 0)
                pr_info("all %u tests passed\n", total_tests);