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authorSiddhesh Poyarekar <siddhesh@sourceware.org>2017-11-20 17:55:59 +0530
committerSiddhesh Poyarekar <siddhesh@sourceware.org>2017-11-20 18:03:32 +0530
commit4d7632ff687dc60fb9ed38bae682d395017b61a8 (patch)
tree3ee504482bd103ea4adb3cf2368451b133c9266a
parenta465b89ee82642c193cfd7deb6eb5d999ffaa5b7 (diff)
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benchtests: Fix walking sizes and directions for *-walk benchmarks
Make the walking benchmarks walk only backwards since copying both ways is biased in favour of implementations that use non-temporal stores for larger sizes; falkor is one of them. This also fixes up bugs in computation of the result which ended up multiplying the length with the timing result unnecessarily. * benchtests/bench-memcpy-walk.c (do_one_test): Copy only backwards. Fix timing computation. * benchtests/bench-memmove-walk.c (do_one_test): Likewise. * benchtests/bench-memset-walk.c (do_one_test): Walk backwards on memset by N at a time. Fix timing computation.
-rw-r--r--ChangeLog8
-rw-r--r--benchtests/bench-memcpy-walk.c14
-rw-r--r--benchtests/bench-memmove-walk.c15
-rw-r--r--benchtests/bench-memset-walk.c4
4 files changed, 20 insertions, 21 deletions
diff --git a/ChangeLog b/ChangeLog
index 225596d10f..746222d423 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2017-11-20 Siddhesh Poyarekar <siddhesh@sourceware.org>
+
+ * benchtests/bench-memcpy-walk.c (do_one_test): Copy only
+ backwards. Fix timing computation.
+ * benchtests/bench-memmove-walk.c (do_one_test): Likewise.
+ * benchtests/bench-memset-walk.c (do_one_test): Walk backwards
+ on memset by N at a time. Fix timing computation.
+
2017-11-20 Florian Weimer <fweimer@redhat.com>
* manual/llio.texi (Memory-mapped I/O): Document MAP_HUGETLB,
diff --git a/benchtests/bench-memcpy-walk.c b/benchtests/bench-memcpy-walk.c
index 69d467d3fe..5b563411ad 100644
--- a/benchtests/bench-memcpy-walk.c
+++ b/benchtests/bench-memcpy-walk.c
@@ -47,26 +47,22 @@ static void
do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src,
size_t len)
{
- size_t i, iters = MIN_PAGE_SIZE / len;
+ size_t i = 0;
timing_t start, stop, cur;
char *dst_end = dst + MIN_PAGE_SIZE - len;
char *src_end = src + MIN_PAGE_SIZE - len;
TIMING_NOW (start);
- /* Copy the entire buffer back and forth, LEN at a time. */
- for (i = 0; i < iters && dst_end >= dst && src <= src_end; src++, dst_end--)
- {
- CALL (impl, dst_end, src, len);
- CALL (impl, src, dst_end, len);
- i += 2;
- }
+ /* Copy the entire buffer backwards, LEN at a time. */
+ for (; src_end >= src && dst_end >= dst; src_end -= len, dst_end -= len, i++)
+ CALL (impl, src_end, dst_end, len);
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
/* Get time taken per function call. */
- json_element_double (json_ctx, (double) cur * len / i);
+ json_element_double (json_ctx, (double) cur / i);
}
static void
diff --git a/benchtests/bench-memmove-walk.c b/benchtests/bench-memmove-walk.c
index 54dcd64292..969ddd94a2 100644
--- a/benchtests/bench-memmove-walk.c
+++ b/benchtests/bench-memmove-walk.c
@@ -47,26 +47,22 @@ static void
do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src,
size_t len)
{
- size_t i, iters = MIN_PAGE_SIZE / len;
+ size_t i = 0;
timing_t start, stop, cur;
char *dst_end = dst + MIN_PAGE_SIZE - len;
char *src_end = src + MIN_PAGE_SIZE - len;
TIMING_NOW (start);
- /* Copy the entire buffer back and forth, LEN at a time. */
- for (i = 0; i < iters && dst_end >= dst && src <= src_end; src++, dst_end--)
- {
- CALL (impl, dst_end, src, len);
- CALL (impl, src, dst_end, len);
- i += 2;
- }
+ /* Copy the entire buffer backwards, LEN at a time. */
+ for (; src_end >= src && dst <= dst_end; dst += len, src_end -= len, i++)
+ CALL (impl, dst, src_end, len);
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
/* Get time taken per function call. */
- json_element_double (json_ctx, (double) cur * len / i);
+ json_element_double (json_ctx, (double) cur / i);
}
static void
@@ -79,7 +75,6 @@ do_test (json_ctx_t *json_ctx, size_t len, bool overlap)
if (overlap)
buf2 = buf1;
- /* First the non-overlapping moves. */
FOR_EACH_IMPL (impl, 0)
do_one_test (json_ctx, impl, (char *) buf2, (char *) buf1, len);
diff --git a/benchtests/bench-memset-walk.c b/benchtests/bench-memset-walk.c
index 59d2626f46..80fbe092b8 100644
--- a/benchtests/bench-memset-walk.c
+++ b/benchtests/bench-memset-walk.c
@@ -66,14 +66,14 @@ do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, CHAR *s_end,
timing_t start, stop, cur;
TIMING_NOW (start);
- for (i = 0; i < iters && s <= s_end; s++, i++)
+ for (i = 0; i < iters && s <= s_end; s_end -= n, i++)
CALL (impl, s, c, n);
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
/* Get time taken per function call. */
- json_element_double (json_ctx, (double) cur * n / i);
+ json_element_double (json_ctx, (double) cur / i);
}
static void