markers-test/test-mark-speed-empty.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
  36 static void noinline test2(const struct marker *mdata,
  37         void *call_private, ...)
  38 {
  39         /* not called */
  40         printk("blah\n");
  41 }
  42
  43 /*
  44  * Generic marker flavor always available.
  45  * Note : the empty asm volatile with read constraint is used here instead of a
  46  * "used" attribute to fix a gcc 4.1.x bug.
  47  * Make sure the alignment of the structure in the __markers section will
  48  * not add unwanted padding between the beginning of the section and the
  49  * structure. Force alignment to the same alignment as the section start.
  50  */
  51 #define __my_trace_mark(generic, name, call_private, format, args...)   \
  52         do {                                                            \
  53                 static const char __mstrtab_##name[]                    \
  54                 __attribute__((section("__markers_strings")))           \
  55                 = #name "\0" format;                                    \
  56                 static struct marker __mark_##name                      \
  57                 __attribute__((section("__markers"), aligned(8))) =     \
  58                 { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)],   \
  59                 0, 0, marker_probe_cb,                                  \
  60                 { __mark_empty_function, NULL}, NULL };                 \
  61                 __mark_check_format(format, ## args);                   \
  62                 if (!generic) {                                         \
  63                         if (unlikely(imv_read(__mark_##name.state)))    \
  64                                 test2                   \
  65                                         (&__mark_##name, call_private,  \
  66                                         ## args);               \
  67                 } else {                                                \
  68                         if (unlikely(_imv_read(__mark_##name.state)))   \
  69                                 test2                   \
  70                                         (&__mark_##name, call_private,  \
  71                                         ## args);               \
  72                 }                                                       \
  73         } while (0)
  74
  75         //asm volatile ("");
  76 struct proc_dir_entry *pentry = NULL;
  77
  78 static inline void test(unsigned long arg, unsigned long arg2)
  79 {
  80         volatile int temp[5];
  81 #ifdef CACHEFLUSH
  82         clflush(&current->pid);
  83         //pmc_flush_cache();
  84 #endif
  85         temp[2] = (temp[0] + 60) << 10;
  86         temp[3] = (temp[2] + 60) << 10;
  87         temp[4] = (temp[3] + 60) << 10;
  88         temp[0] = (temp[4] + 60) << 10;
  89         barrier();
  90         asm ("");
  91         barrier();
  92         //__my_trace_mark(1, kernel_debug_test, NULL, "%d %d %ld %ld", 2, current->pid, arg, arg2);
  93         //__my_trace_mark(0, kernel_debug_test, NULL, "%d %d %ld %ld", 2, current->pid, arg, arg2);
  94 }
  95
  96 static int my_open(struct inode *inode, struct file *file)
  97 {
  98         unsigned int i;
  99         cycles_t cycles1, cycles2;
 100         unsigned long flags;
 101
 102         local_irq_save(flags);
 103 #ifdef CACHEFLUSH
 104         //pmc_flush_cache();    /* initial write back, without cycle count */
 105         //msleep(20);   /* wait for L2 flush */
 106 #endif
 107         rdtsc_barrier();
 108         cycles1 = get_cycles();
 109         rdtsc_barrier();
 110         for(i=0; i<2000; 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                 test(i, i);
 120                 test(i, i);
 121         }
 122         rdtsc_barrier();
 123         cycles2 = get_cycles();
 124         rdtsc_barrier();
 125         local_irq_restore(flags);
 126         printk("cycles : %llu\n", cycles2-cycles1);
 127         return -EPERM;
 128 }
 129
 130
 131 static struct file_operations my_operations = {
 132         .open = my_open,
 133 };
 134
 135 int init_module(void)
 136 {
 137         pentry = create_proc_entry("testmark", 0444, NULL);
 138         if (pentry)
 139                 pentry->proc_fops = &my_operations;
 140
 141         return 0;
 142 }
 143
 144 void cleanup_module(void)
 145 {
 146         remove_proc_entry("testmark", NULL);
 147 }
 148
 149 MODULE_LICENSE("GPL");
 150 MODULE_AUTHOR("Mathieu Desnoyers");
 151 MODULE_DESCRIPTION("Marker Test");
 152 MODULE_VERSION("1.0");
 153