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     /* write back and invalidate cache (a serializing instruction) */
  16
  17     __asm__ __volatile__ ( "wbinvd" : : : "memory" );
  18
  19     /* The wbinvd instruction does not wait for the external caches
  20      * to be flushed, but only requests that it be done.  The loop
  21      * is to be sure that enough time has elapsed, but the compiler
  22      * might simplify or even remove it.  The loop bound is for a
  23      * 512 KB L2 cache.  On a Pentium Pro/II/III, the loop uses
  24      * 2 cycles per iteration.
  25      *
  26      * Does wbinvd also cause the TLB to be flushed?
  27      * A comment in mtrr.c suggests that it does.
  28      */
  29     { register int i; for (i = 0; i < 512*1024; i++) { } }
  30   }
  31
  32
  33 static void noinline test2(const struct marker *mdata,
  34         void *call_private, ...)
  35 {
  36         /* not called */
  37         printk("blah\n");
  38 }
  39
  40 /*
  41  * Generic marker flavor always available.
  42  * Note : the empty asm volatile with read constraint is used here instead of a
  43  * "used" attribute to fix a gcc 4.1.x bug.
  44  * Make sure the alignment of the structure in the __markers section will
  45  * not add unwanted padding between the beginning of the section and the
  46  * structure. Force alignment to the same alignment as the section start.
  47  */
  48 #define __my_trace_mark(generic, name, call_private, format, args...)   \
  49         do {                                                            \
  50                 static const char __mstrtab_##name[]                    \
  51                 __attribute__((section("__markers_strings")))           \
  52                 = #name "\0" format;                                    \
  53                 static struct marker __mark_##name                      \
  54                 __attribute__((section("__markers"), aligned(8))) =     \
  55                 { __mstrtab_##name, &__mstrtab_##name[sizeof(#name)],   \
  56                 0, 0, marker_probe_cb,                                  \
  57                 { __mark_empty_function, NULL}, NULL };                 \
  58                 __mark_check_format(format, ## args);                   \
  59                 if (!generic) {                                         \
  60                         if (unlikely(imv_read(__mark_##name.state)))    \
  61                                 test2                   \
  62                                         (&__mark_##name, call_private,  \
  63                                         ## args);               \
  64                 } else {                                                \
  65                         if (unlikely(_imv_read(__mark_##name.state)))   \
  66                                 test2                   \
  67                                         (&__mark_##name, call_private,  \
  68                                         ## args);               \
  69                 }                                                       \
  70         } while (0)
  71
  72         //asm volatile ("");
  73 struct proc_dir_entry *pentry = NULL;
  74
  75 char temp0[8192];
  76 int temp[8192] __cacheline_aligned;
  77 char temp5[8192];
  78
  79 static inline void test(unsigned long arg, unsigned long arg2)
  80 {
  81 #ifdef CACHEFLUSH
  82         pmc_flush_cache();
  83 #endif
  84         temp[2] = (temp[0] + 60) << 10;
  85         temp[3] = (temp[2] + 60) << 10;
  86         temp[4] = (temp[3] + 60) << 10;
  87         temp[0] = (temp[4] + 60) << 10;
  88         barrier();
  89         asm ("");
  90         barrier();
  91         //__my_trace_mark(1, kernel_debug_test, NULL, "%d %d %ld %ld", 2, current->pid, arg, arg2);
  92         //__my_trace_mark(0, kernel_debug_test, NULL, "%d %d %ld %ld", 2, current->pid, arg, arg2);
  93 }
  94
  95 static int my_open(struct inode *inode, struct file *file)
  96 {
  97         unsigned int i;
  98         cycles_t cycles1, cycles2;
  99         unsigned long flags;
 100
 101         local_irq_save(flags);
 102 #ifdef CACHEFLUSH
 103         pmc_flush_cache();      /* initial write back, without cycle count */
 104         msleep(20);     /* wait for L2 flush */
 105 #endif
 106         rdtsc_barrier();
 107         cycles1 = get_cycles();
 108         rdtsc_barrier();
 109         for(i=0; i<2000; 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                 test(i, i);
 120         }
 121         rdtsc_barrier();
 122         cycles2 = get_cycles();
 123         rdtsc_barrier();
 124         local_irq_restore(flags);
 125         printk("cycles : %llu\n", cycles2-cycles1);
 126         return -EPERM;
 127 }
 128
 129
 130 static struct file_operations my_operations = {
 131         .open = my_open,
 132 };
 133
 134 int init_module(void)
 135 {
 136         pentry = create_proc_entry("testmark", 0444, NULL);
 137         if (pentry)
 138                 pentry->proc_fops = &my_operations;
 139
 140         return 0;
 141 }
 142
 143 void cleanup_module(void)
 144 {
 145         remove_proc_entry("testmark", NULL);
 146 }
 147
 148 MODULE_LICENSE("GPL");
 149 MODULE_AUTHOR("Mathieu Desnoyers");
 150 MODULE_DESCRIPTION("Marker Test");
 151 MODULE_VERSION("1.0");
 152