kernel/fiasco/src/jdb/jdb_kern_info-bench.cpp

   1 INTERFACE:
   2
   3 #include "jdb.h"
   4
   5 class Jdb_kern_info_bench : public Jdb_kern_info_module
   6 {
   7 private:
   8   static Unsigned64 get_time_now();
   9   static void show_arch();
  10 };
  11
  12 //---------------------------------------------------------------------------
  13 IMPLEMENTATION:
  14
  15 static Jdb_kern_info_bench k_a INIT_PRIORITY(JDB_MODULE_INIT_PRIO+1);
  16
  17 PUBLIC
  18 Jdb_kern_info_bench::Jdb_kern_info_bench()
  19   : Jdb_kern_info_module('b', "Benchmark privileged instructions")
  20 {
  21   Jdb_kern_info::register_subcmd(this);
  22 }
  23
  24 PUBLIC
  25 void
  26 Jdb_kern_info_bench::show()
  27 {
  28   do_mp_benchmark();
  29   show_arch();
  30 }
  31
  32 //---------------------------------------------------------------------------
  33 IMPLEMENTATION [!mp]:
  34
  35 PRIVATE
  36 void
  37 Jdb_kern_info_bench::do_mp_benchmark()
  38 {}
  39
  40 //---------------------------------------------------------------------------
  41 IMPLEMENTATION [mp && (ia32 || amd64)]:
  42
  43 #include "idt.h"
  44
  45 PRIVATE static inline
  46 void
  47 Jdb_kern_info_bench::stop_timer()
  48 {
  49   Timer_tick::set_vectors_stop();
  50 }
  51
  52 //---------------------------------------------------------------------------
  53 IMPLEMENTATION [mp && !(ia32 || amd64)]:
  54
  55 PRIVATE static inline
  56 void
  57 Jdb_kern_info_bench::stop_timer()
  58 {}
  59
  60 //---------------------------------------------------------------------------
  61 IMPLEMENTATION [mp]:
  62
  63 #include "ipi.h"
  64
  65 static int volatile ipi_bench_spin_done;
  66 static int ipi_cnt;
  67
  68 PRIVATE static
  69 void
  70 Jdb_kern_info_bench::wait_for_ipi(Cpu_number cpu)
  71 {
  72   Jdb::restore_irqs(cpu);
  73   stop_timer();
  74   Proc::sti();
  75
  76   while (!ipi_bench_spin_done)
  77     Proc::pause();
  78
  79   Proc::cli();
  80   Jdb::save_disable_irqs(cpu);
  81 }
  82
  83 PRIVATE static
  84 void
  85 Jdb_kern_info_bench::empty_func(Cpu_number, void *)
  86 {
  87   ++ipi_cnt;
  88 }
  89
  90 PRIVATE static
  91 void
  92 Jdb_kern_info_bench::do_ipi_bench(Cpu_number my_cpu, Cpu_number partner)
  93 {
  94   Unsigned64 time;
  95   enum {
  96     Runs2  = 3,
  97     Warmup = 4,
  98     Rounds = (1 << Runs2) + Warmup,
  99   };
 100   unsigned i;
 101
 102   ipi_cnt = 0;
 103   Mem::barrier();
 104
 105   for (i = 0; i < Warmup; ++i)
 106     Jdb::remote_work_ipi(my_cpu, partner, empty_func, 0, true);
 107
 108   time = get_time_now();
 109   for (i = 0; i < (1 << Runs2); i++)
 110     Jdb::remote_work_ipi(my_cpu, partner, empty_func, 0, true);
 111
 112   printf(" %2u:%8llu", cxx::int_value<Cpu_number>(partner),
 113          (get_time_now() - time) >> Runs2);
 114
 115   if (ipi_cnt != Rounds)
 116     printf("\nCounter mismatch: cnt=%d v %d\n", ipi_cnt, Rounds);
 117
 118   ipi_bench_spin_done = 1;
 119   Mem::barrier();
 120 }
 121
 122 PRIVATE
 123 void
 124 Jdb_kern_info_bench::do_mp_benchmark()
 125 {
 126   // IPI bench matrix
 127   printf("IPI round-trips:\n");
 128   for (Cpu_number u = Cpu_number::first(); u < Config::max_num_cpus(); ++u)
 129     if (Cpu::online(u))
 130       {
 131         printf("l%2u: ", cxx::int_value<Cpu_number>(u));
 132
 133         for (Cpu_number v = Cpu_number::first(); v < Config::max_num_cpus(); ++v)
 134           if (Cpu::online(v))
 135             {
 136               if (u == v)
 137                 printf(" %2u:%8s", cxx::int_value<Cpu_number>(u), "X");
 138               else
 139                 {
 140                   ipi_bench_spin_done = 0;
 141
 142                   // v is waiting for IPIs
 143                   if (v != Cpu_number::boot_cpu())
 144                     Jdb::remote_work(v, wait_for_ipi, false);
 145
 146                   // u is doing benchmark
 147                   if (u == Cpu_number::boot_cpu())
 148                     do_ipi_bench(Cpu_number::boot_cpu(), v);
 149                   else
 150                     Jdb::remote_work(u, [this, v](Cpu_number cpu){ do_ipi_bench(cpu, v); }, false);
 151
 152                   // v is waiting for IPIs
 153                   if (v == Cpu_number::boot_cpu())
 154                     wait_for_ipi(Cpu_number::boot_cpu());
 155
 156                   Mem::barrier();
 157
 158                   while (!ipi_bench_spin_done)
 159                     Proc::pause();
 160                 }
 161             }
 162         printf("\n");
 163       }
 164 }