markers-test/test-mark-speed.c

   1 /* test-mark.c
   2  *
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/proc_fs.h>
   7 #include <linux/sched.h>
   8 #include <linux/timex.h>
   9 #include <linux/marker.h>
  10 #include <asm/ptrace.h>
  11 #include <asm/system.h>
  12
  13 static void pmc_flush_cache(void)
  14 {
  15     register int i;
  16     /* write back and invalidate cache (a serializing instruction) */
  17
  18     __asm__ __volatile__ ( "wbinvd" : : : "memory" );
  19
  20     /* The wbinvd instruction does not wait for the external caches
  21      * to be flushed, but only requests that it be done.  The loop
  22      * is to be sure that enough time has elapsed, but the compiler
  23      * might simplify or even remove it.  The loop bound is for a
  24      * 512 KB L2 cache.  On a Pentium Pro/II/III, the loop uses
  25      * 2 cycles per iteration.
  26      *
  27      * Does wbinvd also cause the TLB to be flushed?
  28      * A comment in mtrr.c suggests that it does.
  29      */
  30     for (i = 0; i < 512*1024; i++) {
  31         cpu_relax();
  32     }
  33 }
  34
  35 static void noinline test2(const struct marker *mdata,
  36         void *call_private, ...)
  37 {
  38         /* not called */
  39         printk("blah\n");
  40 }
  41
  42 /*
  43  * Generic marker flavor always available.
  44  * Note : the empty asm volatile with read constraint is used here instead of a
  45  * "used" attribute to fix a gcc 4.1.x bug.
  46  * Make sure the alignment of the structure in the __markers section will
  47  * not add unwanted padding between the beginning of the section and the
  48  * structure. Force alignment to the same alignment as the section start.
  49  */
  50 #define __my_trace_mark(generic, name, call_private, format, args...)   \
  51         do {                                                            \
  52                 static const char __mstrtab_##name[]                    \
  53                 __attribute__((section("__markers_strings")))           \
  54                 = #name "\0" format;                                    \
  55                 static struct marker __mark_##name                      \
  56                 __attribute__((section("__markers"), aligned(8))) =     \
  57                 { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)],   \
  58                 0, 0, marker_probe_cb,                                  \
  59                 { __mark_empty_function, NULL}, NULL };                 \
  60                 __mark_check_format(format, ## args);                   \
  61                 if (!generic) {                                         \
  62                         if (unlikely(imv_read(__mark_##name.state)))    \
  63                                 test2                   \
  64                                         (&__mark_##name, call_private,  \
  65                                         ## args);               \
  66                 } else {                                                \
  67                         if (unlikely(_imv_read(__mark_##name.state)))   \
  68                                 test2                   \
  69                                         (&__mark_##name, call_private,  \
  70                                         ## args);               \
  71                 }                                                       \
  72         } while (0)
  73
  74         //asm volatile ("");
  75 struct proc_dir_entry *pentry = NULL;
  76
  77 static inline void test(unsigned long arg, unsigned long arg2)
  78 {
  79         volatile int temp[5];
  80 #ifdef CACHEFLUSH
  81         clflush(&current->pid);
  82 #endif
  83         temp[2] = (temp[0] + 60) << 10;
  84         temp[3] = (temp[2] + 60) << 10;
  85         temp[4] = (temp[3] + 60) << 10;
  86         temp[0] = (temp[4] + 60) << 10;
  87         //asm volatile ("");
  88         barrier();
  89         __my_trace_mark(1, kernel_debug_test, NULL, "%d %d %ld %ld", 2, current->pid, arg, arg2);
  90         barrier();
  91         //__my_trace_mark(0, kernel_debug_test, NULL, "%d %d %ld %ld", 2, current->pid, arg, arg2);
  92 }
  93
  94 static int my_open(struct inode *inode, struct file *file)
  95 {
  96         unsigned int i;
  97         cycles_t cycles1, cycles2;
  98         unsigned long flags;
  99
 100         local_irq_save(flags);
 101 #ifdef CACHEFLUSH
 102         //pmc_flush_cache();    /* initial write back, without cycle count */
 103         //msleep(20);   /* wait for L2 flush */
 104 #endif
 105         rdtsc_barrier();
 106         cycles1 = get_cycles();
 107         rdtsc_barrier();
 108         for(i=0; i<2000; i++) {
 109                 test(i, i);
 110                 test(i, i);
 111                 test(i, i);
 112                 test(i, i);
 113                 test(i, i);
 114                 test(i, i);
 115                 test(i, i);
 116                 test(i, i);
 117                 test(i, i);
 118                 test(i, i);
 119         }
 120         rdtsc_barrier();
 121         cycles2 = get_cycles();
 122         rdtsc_barrier();
 123         local_irq_restore(flags);
 124         printk("cycles : %llu\n", cycles2-cycles1);
 125         return -EPERM;
 126 }
 127
 128
 129 static struct file_operations my_operations = {
 130         .open = my_open,
 131 };
 132
 133 int init_module(void)
 134 {
 135         pentry = create_proc_entry("testmark", 0444, NULL);
 136         if (pentry)
 137                 pentry->proc_fops = &my_operations;
 138
 139         return 0;
 140 }
 141
 142 void cleanup_module(void)
 143 {
 144         remove_proc_entry("testmark", NULL);
 145 }
 146
 147 MODULE_LICENSE("GPL");
 148 MODULE_AUTHOR("Mathieu Desnoyers");
 149 MODULE_DESCRIPTION("Marker Test");
 150 MODULE_VERSION("1.0");