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authorWilco Dijkstra <wdijkstr@arm.com>2017-06-20 16:26:26 +0100
committerWilco Dijkstra <wdijkstr@arm.com>2017-06-20 16:26:26 +0100
commitbeb52f502f0477465313675d2a0fbf3962e130b8 (patch)
tree6d8953c8fab0f45f01c04ab89171a2211b599686
parentc0b23001a89b79f8d0bebe41bfbe64d840b13191 (diff)
downloadglibc-beb52f502f0477465313675d2a0fbf3962e130b8.tar.gz
Improve math benchmark infrastructure
Improve support for math function benchmarking. This patch adds a feature that allows accurate benchmarking of traces extracted from real workloads. This is done by iterating over all samples rather than repeating each sample many times (which completely ignores branch prediction and cache effects). A trace can be added to existing math function inputs via "## name: workload-<name>", followed by the trace. * benchtests/README: Describe workload feature. * benchtests/bench-skeleton.c (main): Add support for benchmarking traces from workloads.
-rw-r--r--ChangeLog6
-rw-r--r--benchtests/README6
-rw-r--r--benchtests/bench-skeleton.c57
3 files changed, 51 insertions, 18 deletions
diff --git a/ChangeLog b/ChangeLog
index 2d81375287..80bb1f847e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2017-06-20 Wilco Dijkstra <wdijkstr@arm.com>
+
+ * benchtests/README: Describe workload feature.
+ * benchtests/bench-skeleton.c (main): Add support for
+ benchmarking traces from workloads.
+
2017-06-20 Zack Weinberg <zackw@panix.com>
* string/string.h (__mempcpy_inline): Delete.
diff --git a/benchtests/README b/benchtests/README
index 2c5f381135..b015acfd53 100644
--- a/benchtests/README
+++ b/benchtests/README
@@ -102,6 +102,12 @@ the same file by using the `name' directive that looks something like this:
See the pow-inputs file for an example of what such a partitioned input file
would look like.
+It is also possible to measure throughput of a (partial) trace extracted from
+a real workload. In this case the whole trace is iterated over multiple times
+rather than repeating every input multiple times. This can be done via:
+
+ ##name: workload-<name>
+
Benchmark Sets:
==============
diff --git a/benchtests/bench-skeleton.c b/benchtests/bench-skeleton.c
index 09eb78df1b..3c6dad7055 100644
--- a/benchtests/bench-skeleton.c
+++ b/benchtests/bench-skeleton.c
@@ -68,34 +68,50 @@ main (int argc, char **argv)
clock_gettime (CLOCK_MONOTONIC_RAW, &runtime);
runtime.tv_sec += DURATION;
+ bool is_bench = strncmp (VARIANT (v), "workload-", 9) == 0;
double d_total_i = 0;
timing_t total = 0, max = 0, min = 0x7fffffffffffffff;
int64_t c = 0;
+ uint64_t cur;
while (1)
{
- for (i = 0; i < NUM_SAMPLES (v); i++)
+ if (is_bench)
{
- uint64_t cur;
+ /* Benchmark a real trace of calls - all samples are iterated
+ over once before repeating. This models actual use more
+ accurately than repeating the same sample many times. */
TIMING_NOW (start);
for (k = 0; k < iters; k++)
- BENCH_FUNC (v, i);
+ for (i = 0; i < NUM_SAMPLES (v); i++)
+ BENCH_FUNC (v, i);
TIMING_NOW (end);
-
TIMING_DIFF (cur, start, end);
+ TIMING_ACCUM (total, cur);
+ d_total_i += iters * NUM_SAMPLES (v);
+ }
+ else
+ for (i = 0; i < NUM_SAMPLES (v); i++)
+ {
+ TIMING_NOW (start);
+ for (k = 0; k < iters; k++)
+ BENCH_FUNC (v, i);
+ TIMING_NOW (end);
- if (cur > max)
- max = cur;
+ TIMING_DIFF (cur, start, end);
- if (cur < min)
- min = cur;
+ if (cur > max)
+ max = cur;
- TIMING_ACCUM (total, cur);
- /* Accumulate timings for the value. In the end we will divide
- by the total iterations. */
- RESULT_ACCUM (cur, v, i, c * iters, (c + 1) * iters);
+ if (cur < min)
+ min = cur;
- d_total_i += iters;
- }
+ TIMING_ACCUM (total, cur);
+ /* Accumulate timings for the value. In the end we will divide
+ by the total iterations. */
+ RESULT_ACCUM (cur, v, i, c * iters, (c + 1) * iters);
+
+ d_total_i += iters;
+ }
c++;
struct timespec curtime;
@@ -117,11 +133,16 @@ main (int argc, char **argv)
json_attr_double (&json_ctx, "duration", d_total_s);
json_attr_double (&json_ctx, "iterations", d_total_i);
- json_attr_double (&json_ctx, "max", max / d_iters);
- json_attr_double (&json_ctx, "min", min / d_iters);
- json_attr_double (&json_ctx, "mean", d_total_s / d_total_i);
+ if (is_bench)
+ json_attr_double (&json_ctx, "throughput", d_total_s / d_total_i);
+ else
+ {
+ json_attr_double (&json_ctx, "max", max / d_iters);
+ json_attr_double (&json_ctx, "min", min / d_iters);
+ json_attr_double (&json_ctx, "mean", d_total_s / d_total_i);
+ }
- if (detailed)
+ if (detailed && !is_bench)
{
json_array_begin (&json_ctx, "timings");