move benchmark to libhermit to avoid side effects with LwIP

kernel/main.c

@@ -569,6 +569,81 @@ out:
 	return 0;
 }
 
+//#define MEASURE_CONTEXT
+
+#ifdef MEASURE_CONTEXT
+
+#define N	10000
+volatile int finished = 0;
+volatile int started1 = 0;
+volatile int started2 = 0;
+
+static int dummy_task(void* arg)
+{
+	kprintf("Enter dummy loop at core %d\n", CORE_ID);
+
+	// cache warm up
+	reschedule();
+	reschedule();
+
+	// synchronize start
+	started2 = 1;
+	mb();
+	while(started1 == 0)
+		reschedule();
+
+	while (finished == 0)
+	{
+		reschedule();
+	}
+
+	kprintf("Leave dummy loop\n");
+
+	return 0;
+}
+
+static int measure_context(void* arg)
+{
+	unsigned long long start, end;
+
+	kprintf("Enter function at core %d to measure the time for a context switch\n", CORE_ID);
+
+	// cache warm up
+	reschedule();
+	reschedule();
+
+	// synchronize start
+	started1 = 1;
+	mb();
+	while(started2 == 0)
+	reschedule();
+
+	// Save the current Time Stamp Counter value and switch to the second task.
+	start = rdtsc();
+	mb();
+
+	for(uint32_t i = 0; i < N; i++)
+	{
+		reschedule();
+	}
+
+	// Calculate the cycle difference and add it to the sum.
+	end = rdtsc();
+	mb();
+
+	finished = 1;
+
+	reschedule();
+	reschedule();
+
+	kprintf("Average time for a task switch: %lld cycles\n", (end - start) / (N * 2));
+
+	sys_exit(0);
+
+	return 0;
+}
+#endif
+
 int hermit_main(void)
 {
 	hermit_init();
@@ -608,7 +683,12 @@ int hermit_main(void)
 	print_cpu_status(isle);
 	//vma_dump();
 
+#ifdef MEASURE_CONTEXT
+	create_kernel_task_on_core(NULL, dummy_task, NULL, NORMAL_PRIO, boot_processor);
+	create_kernel_task_on_core(NULL, measure_context, NULL, NORMAL_PRIO, boot_processor);
+#else
 	create_kernel_task_on_core(NULL, initd, NULL, NORMAL_PRIO, boot_processor);
+#endif
 
 	while(1) {
 		check_workqueues();

usr/benchmarks/CMakeLists.txt

@@ -17,7 +17,5 @@ add_executable(stream stream.c)
 target_compile_options(stream PRIVATE -fopenmp)
 target_link_libraries(stream -fopenmp)
 
-add_executable(taskswitch taskswitch.c)
-
 # deployment
 install_local_targets(extra/benchmarks)

usr/benchmarks/taskswitch.c

@@ -1,150 +0,0 @@
-// Copyright (c) 2018 Colin Finck, RWTH Aachen University
-//
-// MIT License
-//
-// Permission is hereby granted, free of charge, to any person obtaining
-// a copy of this software and associated documentation files (the
-// "Software"), to deal in the Software without restriction, including
-// without limitation the rights to use, copy, modify, merge, publish,
-// distribute, sublicense, and/or sell copies of the Software, and to
-// permit persons to whom the Software is furnished to do so, subject to
-// the following conditions:
-//
-// The above copyright notice and this permission notice shall be
-// included in all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
-// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
-// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-////////////////////////////////////
-//// HERMITCORE C-SPECIFIC CODE ////
-
-#include <hermit/syscall.h>
-
-#define NORMAL_PRIO     8
-typedef int (*entry_point_t)(void*);
-int create_kernel_task_on_core(tid_t* id, entry_point_t ep, void* args, uint8_t prio, uint32_t core_id);
-void reschedule(void);
-
-inline static void create_second_task(void (*entry_point)(void*))
-{
-	create_kernel_task_on_core(NULL, (entry_point_t)entry_point, NULL, NORMAL_PRIO, 0);
-}
-
-inline static void consume_task_time(void)
-{
-	// Not required for the HermitCore C version.
-}
-
-inline static void switch_task(void)
-{
-	reschedule();
-}
-
-
-///////////////////////////////////
-//// THE ACTUAL BENCHMARK CODE ////
-
-#include <stdbool.h>
-#include <stdio.h>
-
-// You can enable this for debugging without any effect on the measurement.
-//#define DEBUG_MESSAGES
-
-#define N		1000
-static bool finished;
-static unsigned long long start;
-static unsigned long long sum;
-
-inline static unsigned long long rdtsc(void)
-{
-	unsigned long lo, hi;
-	asm volatile ("rdtsc" : "=a"(lo), "=d"(hi) :: "memory");
-	return ((unsigned long long) hi << 32ULL | (unsigned long long) lo);
-}
-
-void second_task(void* arg)
-{
-	unsigned long long end;
-
-	for(;;)
-	{
-		// Calculate the cycle difference and add it to the sum.
-		end = rdtsc();
-		sum += (end - start);
-
-		// Check if the benchmark has finished and we can end the second task.
-		if (finished)
-		{
-			break;
-		}
-
-#ifdef DEBUG_MESSAGES
-		printf("Hello from task 2\n");
-#endif
-
-		consume_task_time();
-
-		// Save the current Time Stamp Counter value and switch back to the
-		// first task.
-		start = rdtsc();
-		switch_task();
-	}
-}
-
-int main(int argc, char** argv)
-{
-	int i;
-	unsigned long long end;
-
-	// Start the second task with the same priority on the boot processor.
-	create_second_task(second_task);
-
-	// Initialize the benchmark.
-	printf("taskswitch test\n");
-	printf("===============\n");
-
-	finished = false;
-	sum = 0;
-
-	// Warm up
-	switch_task();
-	switch_task();
-
-	// Run the benchmark.
-	sum = 0;
-	for(i = 0; i < N; i++)
-	{
-#ifdef DEBUG_MESSAGES
-		printf("Hello from task 1\n");
-#endif
-
-		consume_task_time();
-
-		// Save the current Time Stamp Counter value and switch to the second
-		// task.
-		start = rdtsc();
-		switch_task();
-
-		// Calculate the cycle difference and add it to the sum.
-		end = rdtsc();
-		sum += (end - start);
-	}
-
-	// Calculate and print the results.
-	// In every loop iteration, task 1 switches to task 2 and task 2 switches
-	// back to task 1.
-	// Therefore, the total number needs to be divided by 2.
-	printf("Average time for a task switch: %lld cycles\n", sum / (N * 2));
-
-	// Finish the second task gracefully.
-	finished = true;
-	switch_task();
-
-	return 0;
-}