linux-imx

// SPDX-License-Identifier: GPL-2.0

#include <linux/delay.h>

#include <linux/module.h>

#include <linux/kthread.h>

#include <linux/trace_clock.h>

​

#define CREATE_TRACE_POINTS

#include "trace_benchmark.h"

​

static struct task_struct *bm_event_thread;

​

static char bm_str[BENCHMARK_EVENT_STRLEN] = "START";

​

static u64 bm_total;

static u64 bm_totalsq;

static u64 bm_last;

static u64 bm_max;

static u64 bm_min;

static u64 bm_first;

static u64 bm_cnt;

static u64 bm_stddev;

static unsigned int bm_avg;

static unsigned int bm_std;

​

static bool ok_to_run;

​

/*

 * This gets called in a loop recording the time it took to write

 * the tracepoint. What it writes is the time statistics of the last

 * tracepoint write. As there is nothing to write the first time

 * it simply writes "START". As the first write is cold cache and

 * the rest is hot, we save off that time in bm_first and it is

 * reported as "first", which is shown in the second write to the

 * tracepoint. The "first" field is writen within the statics from

 * then on but never changes.

 */

static void trace_do_benchmark(void)

{

    u64 start;

    u64 stop;

    u64 delta;

    u64 stddev;

    u64 seed;

    u64 last_seed;

    unsigned int avg;

    unsigned int std = 0;

​

    /* Only run if the tracepoint is actually active */

    if (!trace_benchmark_event_enabled() || !tracing_is_on())

        return;

​

    local_irq_disable();

    start = trace_clock_local();

    trace_benchmark_event(bm_str);

    stop = trace_clock_local();

    local_irq_enable();

​

    bm_cnt++;

​

    delta = stop - start;

​

    /*

     * The first read is cold cached, keep it separate from the