bsd/kern/kern_clock.c

   1 /*
   2  * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*-
  30  * Copyright (c) 1982, 1986, 1991, 1993
  31  *      The Regents of the University of California.  All rights reserved.
  32  * (c) UNIX System Laboratories, Inc.
  33  * All or some portions of this file are derived from material licensed
  34  * to the University of California by American Telephone and Telegraph
  35  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  36  * the permission of UNIX System Laboratories, Inc.
  37  *
  38  * Redistribution and use in source and binary forms, with or without
  39  * modification, are permitted provided that the following conditions
  40  * are met:
  41  * 1. Redistributions of source code must retain the above copyright
  42  *    notice, this list of conditions and the following disclaimer.
  43  * 2. Redistributions in binary form must reproduce the above copyright
  44  *    notice, this list of conditions and the following disclaimer in the
  45  *    documentation and/or other materials provided with the distribution.
  46  * 3. All advertising materials mentioning features or use of this software
  47  *    must display the following acknowledgement:
  48  *      This product includes software developed by the University of
  49  *      California, Berkeley and its contributors.
  50  * 4. Neither the name of the University nor the names of its contributors
  51  *    may be used to endorse or promote products derived from this software
  52  *    without specific prior written permission.
  53  *
  54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  64  * SUCH DAMAGE.
  65  *
  66  *      @(#)kern_clock.c        8.5 (Berkeley) 1/21/94
  67  */
  68 /*
  69  * HISTORY
  70  */
  71
  72 #include <machine/spl.h>
  73
  74 #include <sys/param.h>
  75 #include <sys/systm.h>
  76 #include <sys/time.h>
  77 #include <sys/resourcevar.h>
  78 #include <sys/kernel.h>
  79 #include <sys/resource.h>
  80 #include <sys/proc_internal.h>
  81 #include <sys/vm.h>
  82 #include <sys/sysctl.h>
  83
  84 #ifdef GPROF
  85 #include <sys/gmon.h>
  86 #endif
  87
  88 #include <kern/thread.h>
  89 #include <kern/ast.h>
  90 #include <kern/assert.h>
  91 #include <mach/boolean.h>
  92
  93 #include <kern/thread_call.h>
  94
  95 void bsd_uprofil(struct time_value *syst, user_addr_t pc);
  96 int tvtohz(struct timeval *tv);
  97
  98 /*
  99  * Clock handling routines.
 100  *
 101  * This code is written to operate with two timers which run
 102  * independently of each other. The main clock, running at hz
 103  * times per second, is used to do scheduling and timeout calculations.
 104  * The second timer does resource utilization estimation statistically
 105  * based on the state of the machine phz times a second. Both functions
 106  * can be performed by a single clock (ie hz == phz), however the
 107  * statistics will be much more prone to errors. Ideally a machine
 108  * would have separate clocks measuring time spent in user state, system
 109  * state, interrupt state, and idle state. These clocks would allow a non-
 110  * approximate measure of resource utilization.
 111  */
 112
 113 /*
 114  * The hz hardware interval timer.
 115  */
 116
 117 int             hz = 100;                /* GET RID OF THIS !!! */
 118 int             tick = (1000000 / 100);  /* GET RID OF THIS !!! */
 119
 120 /*
 121  * Kernel timeout services.
 122  */
 123
 124 /*
 125  *      Set a timeout.
 126  *
 127  *      fcn:            function to call
 128  *      param:          parameter to pass to function
 129  *      interval:       timeout interval, in hz.
 130  */
 131 void
 132 timeout(
 133         timeout_fcn_t                   fcn,
 134         void                                    *param,
 135         int                                             interval)
 136 {
 137         uint64_t                deadline;
 138
 139         clock_interval_to_deadline(interval, NSEC_PER_SEC / hz, &deadline);
 140         thread_call_func_delayed((thread_call_func_t)fcn, param, deadline);
 141 }
 142
 143 /*
 144  * Cancel a timeout.
 145  */
 146 void
 147 untimeout(
 148         timeout_fcn_t           fcn,
 149         void                    *param)
 150 {
 151         thread_call_func_cancel((thread_call_func_t)fcn, param, FALSE);
 152 }
 153
 154
 155 /*
 156  *      Set a timeout.
 157  *
 158  *      fcn:            function to call
 159  *      param:          parameter to pass to function
 160  *      ts:             timeout interval, in timespec
 161  */
 162 void
 163 bsd_timeout(
 164         timeout_fcn_t                   fcn,
 165         void                                    *param,
 166         struct timespec         *ts)
 167 {
 168         uint64_t                deadline = 0;
 169
 170         if (ts && (ts->tv_sec || ts->tv_nsec)) {
 171                 nanoseconds_to_absolutetime((uint64_t)ts->tv_sec * NSEC_PER_SEC + ts->tv_nsec,  &deadline );
 172                 clock_absolutetime_interval_to_deadline( deadline, &deadline );
 173         }
 174         thread_call_func_delayed((thread_call_func_t)fcn, param, deadline);
 175 }
 176
 177 /*
 178  * Cancel a timeout.
 179  */
 180 void
 181 bsd_untimeout(
 182         timeout_fcn_t           fcn,
 183         void                    *param)
 184 {
 185         thread_call_func_cancel((thread_call_func_t)fcn, param, FALSE);
 186 }
 187
 188
 189 /*
 190  * Compute number of hz until specified time.
 191  * Used to compute third argument to timeout() from an
 192  * absolute time.
 193  */
 194 int
 195 hzto(struct timeval *tv)
 196 {
 197         struct timeval now;
 198         long ticks;
 199         long sec;
 200
 201         microtime(&now);
 202         /*
 203          * If number of milliseconds will fit in 32 bit arithmetic,
 204          * then compute number of milliseconds to time and scale to
 205          * ticks.  Otherwise just compute number of hz in time, rounding
 206          * times greater than representible to maximum value.
 207          *
 208          * Delta times less than 25 days can be computed ``exactly''.
 209          * Maximum value for any timeout in 10ms ticks is 250 days.
 210          */
 211         sec = tv->tv_sec - now.tv_sec;
 212         if (sec <= 0x7fffffff / 1000 - 1000)
 213                 ticks = ((tv->tv_sec - now.tv_sec) * 1000 +
 214                         (tv->tv_usec - now.tv_usec) / 1000)
 215                                 / (tick / 1000);
 216         else if (sec <= 0x7fffffff / hz)
 217                 ticks = sec * hz;
 218         else
 219                 ticks = 0x7fffffff;
 220
 221         return (ticks);
 222 }
 223
 224 /*
 225  * Return information about system clocks.
 226  */
 227 static int
 228 sysctl_clockrate
 229 (__unused struct sysctl_oid *oidp, __unused void *arg1, __unused int arg2, __unused struct sysctl_req *req)
 230 {
 231         struct clockinfo clkinfo;
 232
 233         /*
 234          * Construct clockinfo structure.
 235          */
 236         clkinfo.hz = hz;
 237         clkinfo.tick = tick;
 238         clkinfo.profhz = hz;
 239         clkinfo.stathz = hz;
 240         return sysctl_io_opaque(req, &clkinfo, sizeof(clkinfo), NULL);
 241 }
 242
 243 SYSCTL_PROC(_kern, KERN_CLOCKRATE, clockrate,
 244                 CTLTYPE_STRUCT | CTLFLAG_RD,
 245                 0, 0, sysctl_clockrate, "S,clockinfo", "");
 246
 247
 248 /*
 249  * Compute number of ticks in the specified amount of time.
 250  */
 251 int
 252 tvtohz(struct timeval *tv)
 253 {
 254         unsigned long ticks;
 255         long sec, usec;
 256
 257         /*
 258          * If the number of usecs in the whole seconds part of the time
 259          * difference fits in a long, then the total number of usecs will
 260          * fit in an unsigned long.  Compute the total and convert it to
 261          * ticks, rounding up and adding 1 to allow for the current tick
 262          * to expire.  Rounding also depends on unsigned long arithmetic
 263          * to avoid overflow.
 264          *
 265          * Otherwise, if the number of ticks in the whole seconds part of
 266          * the time difference fits in a long, then convert the parts to
 267          * ticks separately and add, using similar rounding methods and
 268          * overflow avoidance.  This method would work in the previous
 269          * case but it is slightly slower and assumes that hz is integral.
 270          *
 271          * Otherwise, round the time difference down to the maximum
 272          * representable value.
 273          *
 274          * If ints have 32 bits, then the maximum value for any timeout in
 275          * 10ms ticks is 248 days.
 276          */
 277         sec = tv->tv_sec;
 278         usec = tv->tv_usec;
 279         if (usec < 0) {
 280                 sec--;
 281                 usec += 1000000;
 282         }
 283         if (sec < 0) {
 284 #ifdef DIAGNOSTIC
 285                 if (usec > 0) {
 286                         sec++;
 287                         usec -= 1000000;
 288                 }
 289                 printf("tvotohz: negative time difference %ld sec %ld usec\n",
 290                        sec, usec);
 291 #endif
 292                 ticks = 1;
 293         } else if (sec <= LONG_MAX / 1000000)
 294                 ticks = (sec * 1000000 + (unsigned long)usec + (tick - 1))
 295                         / tick + 1;
 296         else if (sec <= LONG_MAX / hz)
 297                 ticks = sec * hz
 298                         + ((unsigned long)usec + (tick - 1)) / tick + 1;
 299         else
 300                 ticks = LONG_MAX;
 301         if (ticks > INT_MAX)
 302                 ticks = INT_MAX;
 303         return ((int)ticks);
 304 }
 305
 306
 307 /*
 308  * Start profiling on a process.
 309  *
 310  * Kernel profiling passes kernel_proc which never exits and hence
 311  * keeps the profile clock running constantly.
 312  */
 313 void
 314 startprofclock(struct proc *p)
 315 {
 316         if ((p->p_flag & P_PROFIL) == 0)
 317                 OSBitOrAtomic(P_PROFIL, (UInt32 *)&p->p_flag);
 318 }
 319
 320 /*
 321  * Stop profiling on a process.
 322  */
 323 void
 324 stopprofclock(struct proc *p)
 325 {
 326         if (p->p_flag & P_PROFIL)
 327                 OSBitAndAtomic(~((uint32_t)P_PROFIL), (UInt32 *)&p->p_flag);
 328 }
 329
 330 /* TBD locking user profiling is not resolved yet */
 331 void
 332 bsd_uprofil(struct time_value *syst, user_addr_t pc)
 333 {
 334         struct proc *p = current_proc();
 335         int             ticks;
 336         struct timeval  *tv;
 337         struct timeval st;
 338
 339         if (p == NULL)
 340                 return;
 341         if ( !(p->p_flag & P_PROFIL))
 342                 return;
 343
 344         st.tv_sec = syst->seconds;
 345         st.tv_usec = syst->microseconds;
 346
 347         tv = &(p->p_stats->p_ru.ru_stime);
 348
 349         ticks = ((tv->tv_sec - st.tv_sec) * 1000 +
 350                 (tv->tv_usec - st.tv_usec) / 1000) /
 351                 (tick / 1000);
 352         if (ticks)
 353                 addupc_task(p, pc, ticks);
 354 }
 355
 356 /* TBD locking user profiling is not resolved yet */
 357 void
 358 get_procrustime(time_value_t *tv)
 359 {
 360         struct proc *p = current_proc();
 361         struct timeval st;
 362
 363         if (p == NULL)
 364                 return;
 365         if ( !(p->p_flag & P_PROFIL))
 366                 return;
 367
 368         //proc_lock(p);
 369         st = p->p_stats->p_ru.ru_stime;
 370         //proc_unlock(p);
 371
 372         tv->seconds = st.tv_sec;
 373         tv->microseconds = st.tv_usec;
 374 }