Re: [PATCH] bitmap: Fix optimization of bitmap_set/clear for big-endian machines

From: Matthew Wilcox
Date: Wed Oct 25 2017 - 08:11:13 EST



(I don't think I can reliably send patches from outlook; sorry for
breaking the threading)

I see where we're not incrementing the failure count ... try this patch!

--- 8< ---

Subject: Fix bitmap optimisation tests to report errors correctly
From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>

I had neglected to increment the error counter when the tests failed,
which made the tests noisy when they fail, but not actually return an
error code.

Reported-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxx

diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c
index aa1f2669bdd5..ae8a830e4e54 100644
--- a/lib/test_bitmap.c
+++ b/lib/test_bitmap.c
@@ -430,23 +430,32 @@ static void noinline __init test_mem_optimisations(void)
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) {
+ memset(bmap1, 0x5a, sizeof(bmap1));
+ memset(bmap2, 0x5a, sizeof(bmap2));
+
bitmap_set(bmap1, start, nbits);
__bitmap_set(bmap2, start, nbits);
- if (!bitmap_equal(bmap1, bmap2, 1024))
+ if (!bitmap_equal(bmap1, bmap2, 1024)) {
printk("set not equal %d %d\n", start, nbits);
- if (!__bitmap_equal(bmap1, bmap2, 1024))
+ failed_tests++;
+ }
+ if (!__bitmap_equal(bmap1, bmap2, 1024)) {
printk("set not __equal %d %d\n", start, nbits);
+ failed_tests++;
+ }

bitmap_clear(bmap1, start, nbits);
__bitmap_clear(bmap2, start, nbits);
- if (!bitmap_equal(bmap1, bmap2, 1024))
+ if (!bitmap_equal(bmap1, bmap2, 1024)) {
printk("clear not equal %d %d\n", start, nbits);
- if (!__bitmap_equal(bmap1, bmap2, 1024))
+ failed_tests++;
+ }
+ if (!__bitmap_equal(bmap1, bmap2, 1024)) {
printk("clear not __equal %d %d\n", start,
nbits);
+ failed_tests++;
+ }
}
}
}