Last active
October 8, 2023 21:33
-
-
Save AlmuHS/69fe3962cbe637c3d47f7ed7b7340139 to your computer and use it in GitHub Desktop.
SMP Demo Code: Execute a bunch of threads, showing by screen which cpu are executing each - 32-bit version
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| #include <stdio.h> | |
| #include <pthread.h> | |
| #include <unistd.h> | |
| #include <sys/types.h> | |
| #define MS_STOP_TIME 100 | |
| #define NUM_THREADS 16 | |
| unsigned int get_apic_id(void){ | |
| unsigned int cpu_eax, cpu_ebx, cpu_ecx, cpu_edx; | |
| cpu_eax = 0x1; | |
| asm ( | |
| "mov %%eax, %0\n\t" | |
| "cpuid\n\t" | |
| "mov %0, %%eax\n\t" | |
| "mov %1, %%ebx\n\t" | |
| "mov %2, %%ecx\n\t" | |
| "mov %3, %%edx\n\t" | |
| : "=r" (cpu_eax), "=r" (cpu_ebx), "=r" (cpu_ecx), "=r" (cpu_edx) | |
| : "0" (cpu_eax) | |
| ); | |
| unsigned int apic_id = cpu_ebx >> 24; | |
| return apic_id; | |
| } | |
| void *thread_routine() | |
| { | |
| while(1){ | |
| unsigned int apic_id = get_apic_id(); | |
| printf ("Thread %u - %x\n",pthread_self(), apic_id); | |
| volatile int time = 0, time2; | |
| while(time < MS_STOP_TIME*100000){ | |
| time++; | |
| time2 = time+1; | |
| } | |
| } | |
| } | |
| int main() | |
| { | |
| pthread_t threads[NUM_THREADS]; | |
| for(int i = 0; i < NUM_THREADS; i++){ | |
| pthread_create(&threads[i],NULL,(void *) &thread_routine, NULL); | |
| } | |
| for(int i = 0; i < NUM_THREADS; i++){ | |
| pthread_join(threads[i],NULL); | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment