Ajay Mohan / Rasperf

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Commit c1f4bba6b2576f42bf0ad0c24ac13c35b5ee1964

Authored by Ajay Mohan
1 parent b20e8571ee
Exists in master

Thread Ctx Switches

Showing 3 changed files with 155 additions and 2 deletions Inline Diff

memory/thd_ctx_mtx.c View file @ c1f4bba
File was created 1 #include<stdio.h>
2 #include<stdlib.h>
3 #include<unistd.h>
4 #include<pthread.h>
5 #include<sys/time.h>
6 #include "rasperf.h"
7 #define NUM_THREADS 2
8 #define ITERATIONS 1000
9
10 pthread_mutex_t LOCK;
11 pthread_mutex_t TRIGGER;
12 pthread_cond_t COND;
13 volatile unsigned int cs_count = 0;
14
15 // Uptil now TRIGGER WAS LOCKED AND THEN RELEASED
16 void * function(void *id){
17 int t_id = *(int *)id;
18
19 // Wait for trigger from parent
20 pthread_mutex_lock(&TRIGGER);
21 pthread_mutex_unlock(&TRIGGER); // So that both start at the same time
22 // Get lock
23 pthread_mutex_lock(&LOCK); //only one thread passes in
24
25 // Wake up other thread if context switch count is greater than 0
26 if (cs_count > 0){
27 pthread_cond_signal(&COND);
28 }
29
30 while(cs_count < ITERATIONS) {
31
32 // Wait for other thread to wake up us
33 cs_count++; //Increment cs count
34 pthread_cond_wait(&COND, &LOCK); //release LOCK and wait for COND
35
36 // wake up other thread
37 pthread_cond_signal(&COND);
38 }
39 pthread_mutex_unlock(&LOCK);
40 pthread_exit(NULL);
41 }
42
43
44 int main(){
45
46 pthread_t threads[NUM_THREADS];
47 int rc, i,id1=1, id2=2;
48 time start, end;
49 int t;
50
51 pthread_mutex_init(&LOCK, NULL); // to protect CS
52 pthread_mutex_init(&TRIGGER, NULL); //This is to start at the same time
53 pthread_cond_init(&COND, NULL); // to wake each other
54
55 pthread_mutex_lock(&TRIGGER); //to stop the threads we are going to create
56
57
58 rc = pthread_create(&threads[0], NULL, function, (void*)&id1); //create first thread
59 if (rc){
60 perror("Thread creation failed!");
61 }
62 rc = pthread_create(&threads[1], NULL, function, (void*)&id2); //create second thread
63 if (rc){
64 perror("Thread creation failed!");
65 }
66
67 getTime(start); // start time
memory/thd_ctxsw.c View file @ c1f4bba
File was created 1 #define _GNU_SOURCE
2 #include<sched.h>
3 #include "rasperf.h"
4 #include<stdio.h>
5 #include<unistd.h>
6 #include<stdlib.h>
7 #include<signal.h>
8 #define STACK_SIZE 4096
9 int pipe_fd[2], tid1, tid2;
10 char buffer[10];
11 int reader(void* arg);
12 int writer(void* arg);
13 int controller(void *arg)
14 {
15 void *tid1_stack = malloc(STACK_SIZE);
16 void *tid2_stack = malloc(STACK_SIZE);
17 tid1 = clone(&writer, tid1_stack+STACK_SIZE, SIGCHLD|CLONE_SIGHAND|CLONE_FS|CLONE_VM|CLONE_FILES|CLONE_THREAD, NULL);
18 tid2 = clone(&reader, tid2_stack+STACK_SIZE, SIGCHLD|CLONE_SIGHAND|CLONE_FS|CLONE_VM|CLONE_FILES|CLONE_THREAD, NULL);
19 return 0;
20 }
21 int reader(void* arg)
22 {
23 read(pipe_fd[0], buffer, 1);
24 return 0;
25 }
26 int writer(void* arg)
27 {
28 write(pipe_fd[1], "a", 1);
29 return 0;
30 }
31 int main(){
32
33 unsigned int regr;
34 time start, end;
35 unsigned int avg;
36 int status, i;
37 void *child_stack = malloc(STACK_SIZE);
38 int thread_pid;
39
40 //asm volatile("mrc p15, 0, %0, c9, c14, 0" : "=r" (regr));
41 //printf("regr: %x\n", regr);
42
43 //initialize communication pipe
44 for (i = 0; i < 1000; i++)
45 {
46 getTime(start);
47 thread_pid = clone(&controller, child_stack+STACK_SIZE, SIGCHLD|CLONE_SIGHAND|CLONE_FS|CLONE_VM|CLONE_FILES|CLONE_THREAD, NULL);
48 waitpid(thread_pid, 0, 0);
49 getTime(end);
50 printf("\nTime Taken %d", diff(end,start));
rasperf.h View file @ c1f4bba
#ifndef __RASPERF_H__ 1 1 #ifndef __RASPERF_H__
#define __RASPERF_H__ 2 2 #define __RASPERF_H__
3 3 #define PI 1
4 #define x86 0
5 #if defined(PI) && PI
6 #define time unsigned int
#define getTime(var) \ 4 7 #define getTime(var) \
asm volatile (\ 5 8 asm volatile (\
"mrc p15, 0, %0, c9, c13, 0":\ 6 9 "mrc p15, 0, %0, c9, c13, 0":\
"=r" (var)); 7 10 "=r" (var));
#define readCCNTStatus(var) \ 8 11 #define readCCNTStatus(var) \
asm volatile (\ 9 12 asm volatile (\
"mrc p15, 0, %0, c9, c14, 0":\ 10 13 "mrc p15, 0, %0, c9, c14, 0":\
"=r" (var)); 11 14 "=r" (var));
15 #define diff(end, begin) (end - begin)
16 #endif
17 #if defined(x86) && x86
18 #define time struct timeval
19 #define getTime(var) gettimeofday(&var, NULL)
20 #define diff(end, begin) \
21 (end.tv_sec*1e6+end.tv_usec - begin.tv_sec*1e6+ begin.tv_usec)
22 #endif
23 #endif