source: mainline/kernel/test/smpcall/smpcall1.c@ 1f8c11f

/*
 */

#include <print.h>
#include <debug.h>

#include <test.h>
#include <smp/smp_call.h>
#include <cpu.h>
#include <macros.h>
#include <config.h>
#include <arch.h>

/* 
 * Maximum total number of smp_calls in the system is: 
 *  128000 == 8^2 * 1000 * 2 
 *  == MAX_CPUS^2 * ITERATIONS * EACH_CPU_INC_PER_ITER
 */
#define MAX_CPUS   8
#define ITERATIONS 1000
#define EACH_CPU_INC_PER_ITER 2


static void inc(void *p)
{
        ASSERT(interrupts_disabled());

        size_t *pcall_cnt = (size_t*)p;
        /* 
         * No synchronization. Tests if smp_calls makes changes 
         * visible to the caller. 
         */
        ++*pcall_cnt;
}


static void test_thread(void *p)
{
        size_t *pcall_cnt = (size_t*)p;
        smp_call_t call_info[MAX_CPUS];
        
        size_t cpu_count = min(config.cpu_count, MAX_CPUS);
        
        for (int iter = 0; iter < ITERATIONS; ++iter) {
                /* Synchronous version. */
                for (unsigned cpu_id = 0; cpu_id < cpu_count; ++cpu_id) {
                        /* 
                         * smp_call should make changes by inc() visible on this cpu. 
                         * As a result we can pass it our pcall_cnt and not worry 
                         * about other synchronization.
                         */
                        smp_call(cpu_id, inc, pcall_cnt);
                }
                
                /* 
                 * Async calls run in parallel on different cpus, so passing the 
                 * same counter would clobber it without additional synchronization.
                 */
                size_t local_cnt[MAX_CPUS] = {0};
                
                /* Now start asynchronous calls. */
                for (unsigned cpu_id = 0; cpu_id < cpu_count; ++cpu_id) {
                        smp_call_async(cpu_id, inc, &local_cnt[cpu_id], &call_info[cpu_id]);
                }
                
                /* And wait for all async calls to complete. */
                for (unsigned cpu_id = 0; cpu_id < cpu_count; ++cpu_id) {
                        smp_call_wait(&call_info[cpu_id]);
                        *pcall_cnt += local_cnt[cpu_id];
                }

                /* Give other threads a chance to run. */
                thread_usleep(10000);
        }
}


const char *test_smpcall1(void)
{
        /* Number of received calls that were sent by cpu[i]. */
        size_t call_cnt[MAX_CPUS] = {0};
        thread_t *thread[MAX_CPUS] = {0};
        
        unsigned int cpu_count = min(config.cpu_count, MAX_CPUS);
        size_t running_thread_cnt = 0;

        TPRINTF("Spawning threads on %u cpus.\n", cpu_count);
        
        /* Create a wired thread on each cpu. */
        for (unsigned int id = 0; id < cpu_count; ++id) {
                thread[id] = thread_create(test_thread, &call_cnt[id], TASK, 
                        THREAD_FLAG_NONE, "smp-call-test");
                
                if (thread[id]) {
                        thread_wire(thread[id], &cpus[id]);
                        ++running_thread_cnt;
                } else {
                        TPRINTF("Failed to create thread on cpu%u.\n", id);
                }
        }

        TPRINTF("Running %u wired threads.\n", running_thread_cnt);

        for (unsigned int i = 0; i < cpu_count; ++i) {
                if (thread[i] != NULL) {
                        thread_ready(thread[i]);
                }
        }
        
        /* Wait for threads to complete. */
        for (unsigned int i = 0; i < cpu_count; ++i) {
                if (thread[i] != NULL) {
                        thread_join(thread[i]);
                }
        }

        TPRINTF("Threads finished. Checking number of smp_call()s.\n");
        
        size_t exp_calls = running_thread_cnt * ITERATIONS * EACH_CPU_INC_PER_ITER;
        size_t exp_calls_sum = exp_calls * cpu_count;
        
        bool ok = true;
        size_t calls_sum = 0;
        
        for (size_t i = 0; i < cpu_count; ++i) {
                if (thread[i] != NULL) {
                        if (call_cnt[i] != exp_calls) {
                                ok = false;
                                TPRINTF("Error: %u instead of %u cpu%u's calls were"
                                        " acknowledged.\n", call_cnt[i], exp_calls, i);
                        } 
                }
                
                calls_sum += call_cnt[i];
        }
        
        if (calls_sum != exp_calls_sum) {
                TPRINTF("Error: total acknowledged sum: %u instead of %u.\n",
                        calls_sum, exp_calls_sum);
                
                ok = false;
        }
        
        if (ok) {
                TPRINTF("Success: number of received smp_calls is as expected (%u).\n",
                        exp_calls_sum);
                return NULL;
        } else
                return "Failed: incorrect acknowledged smp_calls.\n";
        
}