The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/i386/isa/prof_machdep.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 1996 Bruce D. Evans.
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  */
   26 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD: releng/7.3/sys/i386/isa/prof_machdep.c 187567 2009-01-21 20:53:36Z jkim $");
   29 
   30 #ifdef GUPROF
   31 #include "opt_i586_guprof.h"
   32 #include "opt_perfmon.h"
   33 
   34 #include <sys/param.h>
   35 #include <sys/systm.h>
   36 #include <sys/bus.h>
   37 #include <sys/cpu.h>
   38 #include <sys/eventhandler.h>
   39 #include <sys/gmon.h>
   40 #include <sys/kernel.h>
   41 #include <sys/smp.h>
   42 #include <sys/sysctl.h>
   43 
   44 #include <machine/clock.h>
   45 #include <machine/perfmon.h>
   46 #include <machine/timerreg.h>
   47 
   48 #define CPUTIME_CLOCK_UNINITIALIZED     0
   49 #define CPUTIME_CLOCK_I8254             1
   50 #define CPUTIME_CLOCK_TSC               2
   51 #define CPUTIME_CLOCK_I586_PMC          3
   52 #define CPUTIME_CLOCK_I8254_SHIFT       7
   53 
   54 int     cputime_bias = 1;       /* initialize for locality of reference */
   55 
   56 static int      cputime_clock = CPUTIME_CLOCK_UNINITIALIZED;
   57 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
   58 static u_int    cputime_clock_pmc_conf = I586_PMC_GUPROF;
   59 static int      cputime_clock_pmc_init;
   60 static struct gmonparam saved_gmp;
   61 #endif
   62 #if defined(I586_CPU) || defined(I686_CPU)
   63 static int      cputime_prof_active;
   64 #endif
   65 #endif /* GUPROF */
   66 
   67 #ifdef __GNUCLIKE_ASM
   68 __asm("                                                         \n\
   69 GM_STATE        =       0                                       \n\
   70 GMON_PROF_OFF   =       3                                       \n\
   71                                                                 \n\
   72         .text                                                   \n\
   73         .p2align 4,0x90                                         \n\
   74         .globl  __mcount                                        \n\
   75         .type   __mcount,@function                              \n\
   76 __mcount:                                                       \n\
   77         #                                                       \n\
   78         # Check that we are profiling.  Do it early for speed.  \n\
   79         #                                                       \n\
   80         cmpl    $GMON_PROF_OFF,_gmonparam+GM_STATE              \n\
   81         je      .mcount_exit                                    \n\
   82         #                                                       \n\
   83         # __mcount is the same as [.]mcount except the caller   \n\
   84         # hasn't changed the stack except to call here, so the  \n\
   85         # caller's raddr is above our raddr.                    \n\
   86         #                                                       \n\
   87         movl    4(%esp),%edx                                    \n\
   88         jmp     .got_frompc                                     \n\
   89                                                                 \n\
   90         .p2align 4,0x90                                         \n\
   91         .globl  .mcount                                         \n\
   92 .mcount:                                                        \n\
   93         .globl  __cyg_profile_func_enter                        \n\
   94 __cyg_profile_func_enter:                                       \n\
   95         cmpl    $GMON_PROF_OFF,_gmonparam+GM_STATE              \n\
   96         je      .mcount_exit                                    \n\
   97         #                                                       \n\
   98         # The caller's stack frame has already been built, so   \n\
   99         # %ebp is the caller's frame pointer.  The caller's     \n\
  100         # raddr is in the caller's frame following the caller's \n\
  101         # caller's frame pointer.                               \n\
  102         #                                                       \n\
  103         movl    4(%ebp),%edx                                    \n\
  104 .got_frompc:                                                    \n\
  105         #                                                       \n\
  106         # Our raddr is the caller's pc.                         \n\
  107         #                                                       \n\
  108         movl    (%esp),%eax                                     \n\
  109                                                                 \n\
  110         pushfl                                                  \n\
  111         pushl   %eax                                            \n\
  112         pushl   %edx                                            \n\
  113         cli                                                     \n\
  114         call    mcount                                          \n\
  115         addl    $8,%esp                                         \n\
  116         popfl                                                   \n\
  117 .mcount_exit:                                                   \n\
  118         ret                                                     \n\
  119 ");
  120 #else /* !__GNUCLIKE_ASM */
  121 #error "this file needs to be ported to your compiler"
  122 #endif /* __GNUCLIKE_ASM */
  123 
  124 #ifdef GUPROF
  125 /*
  126  * [.]mexitcount saves the return register(s), loads selfpc and calls
  127  * mexitcount(selfpc) to do the work.  Someday it should be in a machine
  128  * dependent file together with cputime(), __mcount and [.]mcount.  cputime()
  129  * can't just be put in machdep.c because it has to be compiled without -pg.
  130  */
  131 #ifdef __GNUCLIKE_ASM
  132 __asm("                                                         \n\
  133         .text                                                   \n\
  134 #                                                               \n\
  135 # Dummy label to be seen when gprof -u hides [.]mexitcount.     \n\
  136 #                                                               \n\
  137         .p2align 4,0x90                                         \n\
  138         .globl  __mexitcount                                    \n\
  139         .type   __mexitcount,@function                          \n\
  140 __mexitcount:                                                   \n\
  141         nop                                                     \n\
  142                                                                 \n\
  143 GMON_PROF_HIRES =       4                                       \n\
  144                                                                 \n\
  145         .p2align 4,0x90                                         \n\
  146         .globl  .mexitcount                                     \n\
  147 .mexitcount:                                                    \n\
  148         .globl  __cyg_profile_func_exit                         \n\
  149 __cyg_profile_func_exit:                                        \n\
  150         cmpl    $GMON_PROF_HIRES,_gmonparam+GM_STATE            \n\
  151         jne     .mexitcount_exit                                \n\
  152         pushl   %edx                                            \n\
  153         pushl   %eax                                            \n\
  154         movl    8(%esp),%eax                                    \n\
  155         pushfl                                                  \n\
  156         pushl   %eax                                            \n\
  157         cli                                                     \n\
  158         call    mexitcount                                      \n\
  159         addl    $4,%esp                                         \n\
  160         popfl                                                   \n\
  161         popl    %eax                                            \n\
  162         popl    %edx                                            \n\
  163 .mexitcount_exit:                                               \n\
  164         ret                                                     \n\
  165 ");
  166 #endif /* __GNUCLIKE_ASM */
  167 
  168 /*
  169  * Return the time elapsed since the last call.  The units are machine-
  170  * dependent.
  171  */
  172 int
  173 cputime()
  174 {
  175         u_int count;
  176         int delta;
  177 #if (defined(I586_CPU) || defined(I686_CPU)) && !defined(SMP) && \
  178     defined(PERFMON) && defined(I586_PMC_GUPROF)
  179         u_quad_t event_count;
  180 #endif
  181         u_char high, low;
  182         static u_int prev_count;
  183 
  184 #if defined(I586_CPU) || defined(I686_CPU)
  185         if (cputime_clock == CPUTIME_CLOCK_TSC) {
  186                 /*
  187                  * Scale the TSC a little to make cputime()'s frequency
  188                  * fit in an int, assuming that the TSC frequency fits
  189                  * in a u_int.  Use a fixed scale since dynamic scaling
  190                  * would be slower and we can't really use the low bit
  191                  * of precision.
  192                  */
  193                 count = (u_int)rdtsc() & ~1u;
  194                 delta = (int)(count - prev_count) >> 1;
  195                 prev_count = count;
  196                 return (delta);
  197         }
  198 #if defined(PERFMON) && defined(I586_PMC_GUPROF) && !defined(SMP)
  199         if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
  200                 /*
  201                  * XXX permon_read() should be inlined so that the
  202                  * perfmon module doesn't need to be compiled with
  203                  * profiling disabled and so that it is fast.
  204                  */
  205                 perfmon_read(0, &event_count);
  206 
  207                 count = (u_int)event_count;
  208                 delta = (int)(count - prev_count);
  209                 prev_count = count;
  210                 return (delta);
  211         }
  212 #endif /* PERFMON && I586_PMC_GUPROF && !SMP */
  213 #endif /* I586_CPU || I686_CPU */
  214 
  215         /*
  216          * Read the current value of the 8254 timer counter 0.
  217          */
  218         outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH);
  219         low = inb(TIMER_CNTR0);
  220         high = inb(TIMER_CNTR0);
  221         count = ((high << 8) | low) << CPUTIME_CLOCK_I8254_SHIFT;
  222 
  223         /*
  224          * The timer counts down from TIMER_CNTR0_MAX to 0 and then resets.
  225          * While profiling is enabled, this routine is called at least twice
  226          * per timer reset (for mcounting and mexitcounting hardclock()),
  227          * so at most one reset has occurred since the last call, and one
  228          * has occurred iff the current count is larger than the previous
  229          * count.  This allows counter underflow to be detected faster
  230          * than in microtime().
  231          */
  232         delta = prev_count - count;
  233         prev_count = count;
  234         if ((int) delta <= 0)
  235                 return (delta + (timer0_max_count << CPUTIME_CLOCK_I8254_SHIFT));
  236         return (delta);
  237 }
  238 
  239 static int
  240 sysctl_machdep_cputime_clock(SYSCTL_HANDLER_ARGS)
  241 {
  242         int clock;
  243         int error;
  244 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
  245         int event;
  246         struct pmc pmc;
  247 #endif
  248 
  249         clock = cputime_clock;
  250 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
  251         if (clock == CPUTIME_CLOCK_I586_PMC) {
  252                 pmc.pmc_val = cputime_clock_pmc_conf;
  253                 clock += pmc.pmc_event;
  254         }
  255 #endif
  256         error = sysctl_handle_opaque(oidp, &clock, sizeof clock, req);
  257         if (error == 0 && req->newptr != NULL) {
  258 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
  259                 if (clock >= CPUTIME_CLOCK_I586_PMC) {
  260                         event = clock - CPUTIME_CLOCK_I586_PMC;
  261                         if (event >= 256)
  262                                 return (EINVAL);
  263                         pmc.pmc_num = 0;
  264                         pmc.pmc_event = event;
  265                         pmc.pmc_unit = 0;
  266                         pmc.pmc_flags = PMCF_E | PMCF_OS | PMCF_USR;
  267                         pmc.pmc_mask = 0;
  268                         cputime_clock_pmc_conf = pmc.pmc_val;
  269                         cputime_clock = CPUTIME_CLOCK_I586_PMC;
  270                 } else
  271 #endif
  272                 {
  273                         if (clock < 0 || clock >= CPUTIME_CLOCK_I586_PMC)
  274                                 return (EINVAL);
  275                         cputime_clock = clock;
  276                 }
  277         }
  278         return (error);
  279 }
  280 
  281 SYSCTL_PROC(_machdep, OID_AUTO, cputime_clock, CTLTYPE_INT | CTLFLAG_RW,
  282             0, sizeof(u_int), sysctl_machdep_cputime_clock, "I", "");
  283 
  284 /*
  285  * The start and stop routines need not be here since we turn off profiling
  286  * before calling them.  They are here for convenience.
  287  */
  288 
  289 void
  290 startguprof(gp)
  291         struct gmonparam *gp;
  292 {
  293         if (cputime_clock == CPUTIME_CLOCK_UNINITIALIZED) {
  294                 cputime_clock = CPUTIME_CLOCK_I8254;
  295 #if defined(I586_CPU) || defined(I686_CPU)
  296                 if (tsc_freq != 0 && !tsc_is_broken && mp_ncpus == 1)
  297                         cputime_clock = CPUTIME_CLOCK_TSC;
  298 #endif
  299         }
  300         gp->profrate = timer_freq << CPUTIME_CLOCK_I8254_SHIFT;
  301 #if defined(I586_CPU) || defined(I686_CPU)
  302         if (cputime_clock == CPUTIME_CLOCK_TSC) {
  303                 gp->profrate = tsc_freq >> 1;
  304                 cputime_prof_active = 1;
  305         }
  306 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
  307         else if (cputime_clock == CPUTIME_CLOCK_I586_PMC) {
  308                 if (perfmon_avail() &&
  309                     perfmon_setup(0, cputime_clock_pmc_conf) == 0) {
  310                         if (perfmon_start(0) != 0)
  311                                 perfmon_fini(0);
  312                         else {
  313                                 /* XXX 1 event == 1 us. */
  314                                 gp->profrate = 1000000;
  315 
  316                                 saved_gmp = *gp;
  317 
  318                                 /* Zap overheads.  They are invalid. */
  319                                 gp->cputime_overhead = 0;
  320                                 gp->mcount_overhead = 0;
  321                                 gp->mcount_post_overhead = 0;
  322                                 gp->mcount_pre_overhead = 0;
  323                                 gp->mexitcount_overhead = 0;
  324                                 gp->mexitcount_post_overhead = 0;
  325                                 gp->mexitcount_pre_overhead = 0;
  326 
  327                                 cputime_clock_pmc_init = TRUE;
  328                         }
  329                 }
  330         }
  331 #endif /* PERFMON && I586_PMC_GUPROF */
  332 #endif /* I586_CPU || I686_CPU */
  333         cputime_bias = 0;
  334         cputime();
  335 }
  336 
  337 void
  338 stopguprof(gp)
  339         struct gmonparam *gp;
  340 {
  341 #if defined(PERFMON) && defined(I586_PMC_GUPROF)
  342         if (cputime_clock_pmc_init) {
  343                 *gp = saved_gmp;
  344                 perfmon_fini(0);
  345                 cputime_clock_pmc_init = FALSE;
  346         }
  347 #endif
  348 #if defined(I586_CPU) || defined(I686_CPU)
  349         if (cputime_clock == CPUTIME_CLOCK_TSC)
  350                 cputime_prof_active = 0;
  351 #endif
  352 }
  353 
  354 #if defined(I586_CPU) || defined(I686_CPU)
  355 /* If the cpu frequency changed while profiling, report a warning. */
  356 static void
  357 tsc_freq_changed(void *arg, const struct cf_level *level, int status)
  358 {
  359 
  360         /*
  361          * If there was an error during the transition or
  362          * TSC is P-state invariant, don't do anything.
  363          */
  364         if (status != 0 || tsc_is_invariant)
  365                 return;
  366         if (cputime_prof_active && cputime_clock == CPUTIME_CLOCK_TSC)
  367                 printf("warning: cpu freq changed while profiling active\n");
  368 }
  369 
  370 EVENTHANDLER_DEFINE(cpufreq_post_change, tsc_freq_changed, NULL,
  371     EVENTHANDLER_PRI_ANY);
  372 #endif /* I586_CPU || I686_CPU */
  373 
  374 #endif /* GUPROF */

Cache object: 7637b72e54b62c8be4daaf0852b80619


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.