source: mainline/kernel/test/smpcall/smpcall1.c@ e9f2f4e

/*
 * Copyright (c) 2012 Adam Hraska
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

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

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

/*
 * Maximum total number of smp_calls in the system is:
 *  162000 == 9^2 * 1000 * 2
 *  == MAX_CPUS^2 * ITERATIONS * EACH_CPU_INC_PER_ITER
 */
#define MAX_CPUS   9
#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];

        unsigned int cpu_count = min(config.cpu_active, 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);
        }
}

static size_t calc_exp_calls(size_t thread_cnt)
{
        return thread_cnt * ITERATIONS * EACH_CPU_INC_PER_ITER;
}

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] = { NULL };

        unsigned int cpu_count = min(config.cpu_active, 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);
                }
        }

        size_t exp_calls = calc_exp_calls(running_thread_cnt);
        size_t exp_calls_sum = exp_calls * cpu_count;

        TPRINTF("Running %zu wired threads. Expecting %zu calls. Be patient.\n",
            running_thread_cnt, exp_calls_sum);

        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]);
                        thread_detach(thread[i]);
                }
        }

        TPRINTF("Threads finished. Checking number of smp_call()s.\n");

        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: %zu instead of %zu cpu%zu'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: %zu instead of %zu.\n",
                    calls_sum, exp_calls_sum);

                ok = false;
        }

        if (ok) {
                TPRINTF("Success: number of received smp_calls is as expected (%zu).\n",
                    exp_calls_sum);
                return NULL;
        } else
                return "Failed: incorrect acknowledged smp_calls.\n";

}