From e7dde95d87e2842085c39fa69eab2e06c565d08c Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@cloudius-systems.com>
Date: Sun, 26 May 2013 19:21:38 +0300
Subject: [PATCH] tst-ctxsw: refine to have warm-up time and fixed execution
time
---
tests/tst-ctxsw.cc | 61 ++++++++++++++++++++++++++++++++++++++++------
1 file changed, 54 insertions(+), 7 deletions(-)
diff --git a/tests/tst-ctxsw.cc b/tests/tst-ctxsw.cc
index 9c1af92f2..3d34115e4 100644
--- a/tests/tst-ctxsw.cc
+++ b/tests/tst-ctxsw.cc
@@ -6,6 +6,9 @@
#include <sys/time.h>
#include <cinttypes>
#include <stdio.h>
+#include <stdint.h>
+
+uint64_t target_time = 10; // seconds
#ifdef __OSV__
@@ -99,10 +102,14 @@ void pinned_thread::join()
pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+pthread_cond_t mgmt_cond = PTHREAD_COND_INITIALIZER;
unsigned owner;
unsigned remain;
-void run(unsigned me)
+bool exiting;
+unsigned nr_running;
+
+void run_once(unsigned me)
{
bool done = false;
while (!done) {
@@ -112,6 +119,7 @@ void run(unsigned me)
}
if (remain == 0) {
done = true;
+ pthread_cond_broadcast(&mgmt_cond);
} else {
--remain;
}
@@ -121,6 +129,22 @@ void run(unsigned me)
}
}
+void run(unsigned me)
+{
+ while (!exiting) {
+ pthread_mutex_lock(&mtx);
+ while (!exiting && !nr_running) {
+ pthread_cond_wait(&mgmt_cond, &mtx);
+ }
+ if (exiting) {
+ pthread_mutex_unlock(&mtx);
+ break;
+ }
+ --nr_running;
+ pthread_mutex_unlock(&mtx);
+ run_once(me);
+ }
+}
uint64_t nstime()
{
@@ -136,19 +160,42 @@ void test(std::string name,
pinned_thread t0([] { run(0); }), t1([] { run(1); });
pin0(t0);
pin1(t1);
- auto n_iterations = 10000000;
- remain = n_iterations;
-
- auto start = nstime();
+ auto n_iterations = 10000;
+ exiting = false;
+ bool converged = false;
+ uint64_t start, end;
t0.start();
t1.start();
+ while (!converged) {
+ n_iterations *= 2;
+ start = nstime();
+
+ pthread_mutex_lock(&mtx);
+ nr_running = 2;
+ remain = n_iterations;
+ pthread_cond_broadcast(&mgmt_cond);
+
+ while (remain) {
+ pthread_cond_wait(&mgmt_cond, &mtx);
+ }
+
+ pthread_mutex_unlock(&mtx);
+
+ end = nstime();
+ converged = (end - start) >= (target_time * 1000000000);
+ }
+
+
+ pthread_mutex_lock(&mtx);
+ exiting = true;
+ pthread_cond_broadcast(&mgmt_cond);
+ pthread_mutex_unlock(&mtx);
+
t0.join();
t1.join();
- auto end = nstime();
-
printf("%10" PRIu64 " %s\n", (end - start) / n_iterations, name.c_str());
}
--
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