lib/mi-perfctr.c

   1 /* -*- mode: C; c-file-style: "linux" -*- */
   2
   3 /* MemProf -- memory profiler and leak detector
   4  * Copyright 1999, 2000, 2001, Red Hat, Inc.
   5  * Copyright 2002, Kristian Rietveld
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21 /*====*/
  22
  23 #include <errno.h>
  24 #include <fcntl.h>
  25 #include <signal.h>
  26 #include <string.h>
  27 #include <sys/ioctl.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <fcntl.h>
  31 #include <ucontext.h>
  32 #include <unistd.h>
  33
  34 #include "perfctr.h"
  35
  36 #include "intercept.h"
  37 #include "mi-perfctr.h"
  38 #include "memintercept.h"
  39 #include "memintercept-utils.h"
  40 #include "stack-frame.h"
  41
  42 static int perfctr_fd = -1;
  43
  44 #undef ENABLE_DEBUG
  45
  46 #ifdef ENABLE_DEBUG
  47 #define MI_DEBUG(arg) mi_debug arg
  48 #else /* !ENABLE_DEBUG */
  49 #define MI_DEBUG(arg) (void)0
  50 #endif /* ENABLE_DEBUG */
  51
  52 /* External declaration */
  53 /* XXX hmm.. */
  54 #define SIGHANDLER_FRAMES 2
  55
  56 static void
  57 sigprof_handler (int unused, siginfo_t *si, ucontext_t *ucontext)
  58 {
  59     int saved_errno = errno;
  60     struct sigcontext *ctx = (struct sigcontext *)&ucontext->uc_mcontext;
  61     MIInfo info;
  62
  63     info.alloc.operation = MI_TIME;
  64     info.alloc.old_ptr = NULL;
  65     info.alloc.new_ptr = NULL;
  66     info.alloc.size = 1;
  67
  68     mi_call_with_signal_backtrace ((void *)ctx->EIPRIP, (void *)ctx->EBPRBP,
  69                                         (void *)ctx->ESPRSP, mi_write_stack, &info);
  70
  71     if (ioctl (perfctr_fd, VPERFCTR_IRESUME) < 0)
  72             mi_perror ("Error restarting handler interrupt");
  73
  74     errno = saved_errno;
  75 }
  76
  77 static MIBool
  78 init_sighandler (void)
  79 {
  80     struct sigaction sa;
  81     sa.sa_handler = (void (*)(int))sigprof_handler;
  82     sigemptyset (&sa.sa_mask);
  83     sa.sa_flags = SA_RESTART | SA_SIGINFO;
  84     if (sigaction (SIGPROF, &sa, NULL) != 0) {
  85             mi_perror ("Error setting up signal handler\n");
  86             return MI_FALSE;
  87     }
  88
  89     return MI_TRUE;
  90 }
  91
  92 MIBool
  93 mi_perfctr_start (int interval)
  94 {
  95         struct perfctr_info info;
  96         struct vperfctr_control control;
  97
  98         MI_DEBUG (("Turning on performance monitoring timer support\n"));
  99
 100         if ((perfctr_fd = open ("/proc/self/perfctr", O_RDONLY)) < 0) {
 101                 mi_perror ("Error opening /proc/self/perfctr");
 102                 goto bail;
 103         }
 104
 105         if (ioctl (perfctr_fd, PERFCTR_INFO, &info) < 0) {
 106                 mi_perror ("Error getting perfctr information");
 107                 goto bail;
 108         }
 109
 110         if (!(info.cpu_features & PERFCTR_FEATURE_PCINT)) {
 111                 mi_debug ("Performance monitoring interrupts not found\n");
 112                 goto bail;
 113         }
 114
 115         if (info.cpu_type != PERFCTR_X86_INTEL_PII &&
 116             info.cpu_type != PERFCTR_X86_INTEL_PIII) {
 117                 mi_debug ("Only support PII and PIII performance monitoring counters, found %d\n", info.cpu_type);
 118                 goto bail;
 119         }
 120
 121         memset(&control, 0, sizeof control);
 122
 123         control.si_signo = SIGPROF;
 124         control.cpu_control.nractrs = 0;
 125         control.cpu_control.nrictrs = 1;
 126         control.cpu_control.tsc_on = 1;
 127         control.cpu_control.pmc_map[0] = 0;
 128         /* CPU_CLK_UNHALTED, USR, ENable, INT */
 129         control.cpu_control.evntsel[0] = 0x79 | (1 << 16) | (1 << 22) | (1 << 20);
 130         control.cpu_control.ireset[0] = - (int) (0.5 + (info.cpu_khz / 1000.) * interval);
 131
 132         if (ioctl (perfctr_fd, VPERFCTR_CONTROL, &control) < 0) {
 133                 mi_perror ("Error setting up performance monitoring counters");
 134                 goto bail;
 135         }
 136
 137         return init_sighandler ();
 138
 139  bail:
 140         if (perfctr_fd != -1)
 141                 close (perfctr_fd);
 142
 143         return MI_FALSE;
 144 }
 145
 146 void
 147 mi_perfctr_stop (void)
 148 {
 149 }