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subr_prof.c revision 1.47
      1  1.47  christos /*	$NetBSD: subr_prof.c,v 1.47 2014/07/10 21:13:52 christos Exp $	*/
      2   1.3       cgd 
      3   1.1       cgd /*-
      4   1.1       cgd  * Copyright (c) 1982, 1986, 1993
      5   1.1       cgd  *	The Regents of the University of California.  All rights reserved.
      6   1.1       cgd  *
      7   1.1       cgd  * Redistribution and use in source and binary forms, with or without
      8   1.1       cgd  * modification, are permitted provided that the following conditions
      9   1.1       cgd  * are met:
     10   1.1       cgd  * 1. Redistributions of source code must retain the above copyright
     11   1.1       cgd  *    notice, this list of conditions and the following disclaimer.
     12   1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     13   1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
     14   1.1       cgd  *    documentation and/or other materials provided with the distribution.
     15  1.28       agc  * 3. Neither the name of the University nor the names of its contributors
     16   1.1       cgd  *    may be used to endorse or promote products derived from this software
     17   1.1       cgd  *    without specific prior written permission.
     18   1.1       cgd  *
     19   1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20   1.1       cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21   1.1       cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22   1.1       cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23   1.1       cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24   1.1       cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25   1.1       cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26   1.1       cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27   1.1       cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28   1.1       cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29   1.1       cgd  * SUCH DAMAGE.
     30   1.1       cgd  *
     31  1.17      fvdl  *	@(#)subr_prof.c	8.4 (Berkeley) 2/14/95
     32   1.1       cgd  */
     33  1.25     lukem 
     34  1.25     lukem #include <sys/cdefs.h>
     35  1.47  christos __KERNEL_RCSID(0, "$NetBSD: subr_prof.c,v 1.47 2014/07/10 21:13:52 christos Exp $");
     36   1.1       cgd 
     37   1.1       cgd #include <sys/param.h>
     38   1.1       cgd #include <sys/systm.h>
     39   1.1       cgd #include <sys/kernel.h>
     40   1.1       cgd #include <sys/proc.h>
     41   1.4       cgd #include <sys/mount.h>
     42   1.4       cgd #include <sys/syscallargs.h>
     43  1.16  jonathan #include <sys/sysctl.h>
     44   1.4       cgd 
     45  1.42        ad #include <sys/cpu.h>
     46   1.9  christos 
     47   1.1       cgd #ifdef GPROF
     48   1.1       cgd #include <sys/malloc.h>
     49   1.1       cgd #include <sys/gmon.h>
     50  1.27   thorpej 
     51  1.27   thorpej MALLOC_DEFINE(M_GPROF, "gprof", "kernel profiling buffer");
     52   1.1       cgd 
     53   1.1       cgd /*
     54   1.1       cgd  * Froms is actually a bunch of unsigned shorts indexing tos
     55   1.1       cgd  */
     56  1.37  christos struct gmonparam _gmonparam = { .state = GMON_PROF_OFF };
     57   1.1       cgd 
     58  1.15       gwr /* Actual start of the kernel text segment. */
     59  1.15       gwr extern char kernel_text[];
     60  1.15       gwr 
     61   1.1       cgd extern char etext[];
     62   1.1       cgd 
     63   1.9  christos 
     64   1.9  christos void
     65  1.32   thorpej kmstartup(void)
     66   1.1       cgd {
     67   1.1       cgd 	char *cp;
     68   1.1       cgd 	struct gmonparam *p = &_gmonparam;
     69   1.1       cgd 	/*
     70   1.1       cgd 	 * Round lowpc and highpc to multiples of the density we're using
     71   1.1       cgd 	 * so the rest of the scaling (here and in gprof) stays in ints.
     72   1.1       cgd 	 */
     73  1.34  christos 	p->lowpc = rounddown(((u_long)kernel_text),
     74  1.15       gwr 		HISTFRACTION * sizeof(HISTCOUNTER));
     75  1.34  christos 	p->highpc = roundup((u_long)etext,
     76  1.15       gwr 		HISTFRACTION * sizeof(HISTCOUNTER));
     77   1.1       cgd 	p->textsize = p->highpc - p->lowpc;
     78  1.14  christos 	printf("Profiling kernel, textsize=%ld [%lx..%lx]\n",
     79   1.1       cgd 	       p->textsize, p->lowpc, p->highpc);
     80   1.1       cgd 	p->kcountsize = p->textsize / HISTFRACTION;
     81   1.1       cgd 	p->hashfraction = HASHFRACTION;
     82   1.1       cgd 	p->fromssize = p->textsize / HASHFRACTION;
     83   1.1       cgd 	p->tolimit = p->textsize * ARCDENSITY / 100;
     84   1.1       cgd 	if (p->tolimit < MINARCS)
     85   1.1       cgd 		p->tolimit = MINARCS;
     86   1.1       cgd 	else if (p->tolimit > MAXARCS)
     87   1.1       cgd 		p->tolimit = MAXARCS;
     88   1.1       cgd 	p->tossize = p->tolimit * sizeof(struct tostruct);
     89  1.47  christos 	cp = malloc(p->kcountsize + p->fromssize + p->tossize,
     90  1.38        ad 	    M_GPROF, M_NOWAIT | M_ZERO);
     91   1.1       cgd 	if (cp == 0) {
     92  1.14  christos 		printf("No memory for profiling.\n");
     93   1.1       cgd 		return;
     94   1.1       cgd 	}
     95   1.1       cgd 	p->tos = (struct tostruct *)cp;
     96   1.1       cgd 	cp += p->tossize;
     97   1.1       cgd 	p->kcount = (u_short *)cp;
     98   1.1       cgd 	cp += p->kcountsize;
     99   1.1       cgd 	p->froms = (u_short *)cp;
    100   1.1       cgd }
    101   1.1       cgd 
    102   1.1       cgd /*
    103   1.1       cgd  * Return kernel profiling information.
    104   1.1       cgd  */
    105  1.29    atatat /*
    106  1.29    atatat  * sysctl helper routine for kern.profiling subtree.  enables/disables
    107  1.29    atatat  * kernel profiling and gives out copies of the profiling data.
    108  1.29    atatat  */
    109  1.29    atatat static int
    110  1.29    atatat sysctl_kern_profiling(SYSCTLFN_ARGS)
    111   1.1       cgd {
    112   1.1       cgd 	struct gmonparam *gp = &_gmonparam;
    113   1.1       cgd 	int error;
    114  1.29    atatat 	struct sysctlnode node;
    115   1.1       cgd 
    116  1.29    atatat 	node = *rnode;
    117  1.23     bjh21 
    118  1.29    atatat 	switch (node.sysctl_num) {
    119   1.1       cgd 	case GPROF_STATE:
    120  1.29    atatat 		node.sysctl_data = &gp->state;
    121  1.29    atatat 		break;
    122   1.1       cgd 	case GPROF_COUNT:
    123  1.29    atatat 		node.sysctl_data = gp->kcount;
    124  1.29    atatat 		node.sysctl_size = gp->kcountsize;
    125  1.29    atatat 		break;
    126   1.1       cgd 	case GPROF_FROMS:
    127  1.29    atatat 		node.sysctl_data = gp->froms;
    128  1.29    atatat 		node.sysctl_size = gp->fromssize;
    129  1.29    atatat 		break;
    130   1.1       cgd 	case GPROF_TOS:
    131  1.29    atatat 		node.sysctl_data = gp->tos;
    132  1.29    atatat 		node.sysctl_size = gp->tossize;
    133  1.29    atatat 		break;
    134   1.1       cgd 	case GPROF_GMONPARAM:
    135  1.29    atatat 		node.sysctl_data = gp;
    136  1.29    atatat 		node.sysctl_size = sizeof(*gp);
    137  1.29    atatat 		break;
    138   1.1       cgd 	default:
    139   1.1       cgd 		return (EOPNOTSUPP);
    140   1.1       cgd 	}
    141  1.29    atatat 
    142  1.29    atatat 	error = sysctl_lookup(SYSCTLFN_CALL(&node));
    143  1.29    atatat 	if (error || newp == NULL)
    144  1.29    atatat 		return (error);
    145  1.29    atatat 
    146  1.29    atatat 	if (node.sysctl_num == GPROF_STATE) {
    147  1.38        ad 		mutex_spin_enter(&proc0.p_stmutex);
    148  1.29    atatat 		if (gp->state == GMON_PROF_OFF)
    149  1.29    atatat 			stopprofclock(&proc0);
    150  1.29    atatat 		else
    151  1.29    atatat 			startprofclock(&proc0);
    152  1.38        ad 		mutex_spin_exit(&proc0.p_stmutex);
    153  1.29    atatat 	}
    154  1.29    atatat 
    155  1.29    atatat 	return (0);
    156  1.29    atatat }
    157  1.29    atatat 
    158  1.29    atatat SYSCTL_SETUP(sysctl_kern_gprof_setup, "sysctl kern.profiling subtree setup")
    159  1.29    atatat {
    160  1.29    atatat 
    161  1.30    atatat 	sysctl_createv(clog, 0, NULL, NULL,
    162  1.30    atatat 		       CTLFLAG_PERMANENT,
    163  1.31    atatat 		       CTLTYPE_NODE, "profiling",
    164  1.31    atatat 		       SYSCTL_DESCR("Profiling information (available)"),
    165  1.29    atatat 		       NULL, 0, NULL, 0,
    166  1.29    atatat 		       CTL_KERN, KERN_PROF, CTL_EOL);
    167  1.29    atatat 
    168  1.30    atatat 	sysctl_createv(clog, 0, NULL, NULL,
    169  1.30    atatat 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    170  1.31    atatat 		       CTLTYPE_INT, "state",
    171  1.31    atatat 		       SYSCTL_DESCR("Profiling state"),
    172  1.29    atatat 		       sysctl_kern_profiling, 0, NULL, 0,
    173  1.29    atatat 		       CTL_KERN, KERN_PROF, GPROF_STATE, CTL_EOL);
    174  1.30    atatat 	sysctl_createv(clog, 0, NULL, NULL,
    175  1.30    atatat 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    176  1.31    atatat 		       CTLTYPE_STRUCT, "count",
    177  1.31    atatat 		       SYSCTL_DESCR("Array of statistical program counters"),
    178  1.29    atatat 		       sysctl_kern_profiling, 0, NULL, 0,
    179  1.29    atatat 		       CTL_KERN, KERN_PROF, GPROF_COUNT, CTL_EOL);
    180  1.30    atatat 	sysctl_createv(clog, 0, NULL, NULL,
    181  1.30    atatat 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    182  1.31    atatat 		       CTLTYPE_STRUCT, "froms",
    183  1.31    atatat 		       SYSCTL_DESCR("Array indexed by program counter of "
    184  1.31    atatat 				    "call-from points"),
    185  1.29    atatat 		       sysctl_kern_profiling, 0, NULL, 0,
    186  1.29    atatat 		       CTL_KERN, KERN_PROF, GPROF_FROMS, CTL_EOL);
    187  1.30    atatat 	sysctl_createv(clog, 0, NULL, NULL,
    188  1.30    atatat 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    189  1.31    atatat 		       CTLTYPE_STRUCT, "tos",
    190  1.31    atatat 		       SYSCTL_DESCR("Array of structures describing "
    191  1.31    atatat 				    "destination of calls and their counts"),
    192  1.29    atatat 		       sysctl_kern_profiling, 0, NULL, 0,
    193  1.29    atatat 		       CTL_KERN, KERN_PROF, GPROF_TOS, CTL_EOL);
    194  1.30    atatat 	sysctl_createv(clog, 0, NULL, NULL,
    195  1.30    atatat 		       CTLFLAG_PERMANENT,
    196  1.31    atatat 		       CTLTYPE_STRUCT, "gmonparam",
    197  1.31    atatat 		       SYSCTL_DESCR("Structure giving the sizes of the above "
    198  1.31    atatat 				    "arrays"),
    199  1.29    atatat 		       sysctl_kern_profiling, 0, NULL, 0,
    200  1.29    atatat 		       CTL_KERN, KERN_PROF, GPROF_GMONPARAM, CTL_EOL);
    201   1.1       cgd }
    202   1.1       cgd #endif /* GPROF */
    203   1.1       cgd 
    204   1.1       cgd /*
    205   1.1       cgd  * Profiling system call.
    206   1.1       cgd  *
    207   1.1       cgd  * The scale factor is a fixed point number with 16 bits of fraction, so that
    208   1.1       cgd  * 1.0 is represented as 0x10000.  A scale factor of 0 turns off profiling.
    209   1.1       cgd  */
    210   1.1       cgd /* ARGSUSED */
    211   1.9  christos int
    212  1.43       dsl sys_profil(struct lwp *l, const struct sys_profil_args *uap, register_t *retval)
    213   1.6   thorpej {
    214  1.43       dsl 	/* {
    215  1.40  drochner 		syscallarg(char *) samples;
    216  1.44       dsl 		syscallarg(size_t) size;
    217  1.44       dsl 		syscallarg(u_long) offset;
    218   1.4       cgd 		syscallarg(u_int) scale;
    219  1.43       dsl 	} */
    220  1.26   thorpej 	struct proc *p = l->l_proc;
    221  1.20  augustss 	struct uprof *upp;
    222   1.1       cgd 
    223   1.4       cgd 	if (SCARG(uap, scale) > (1 << 16))
    224   1.1       cgd 		return (EINVAL);
    225   1.4       cgd 	if (SCARG(uap, scale) == 0) {
    226  1.38        ad 		mutex_spin_enter(&p->p_stmutex);
    227   1.1       cgd 		stopprofclock(p);
    228  1.38        ad 		mutex_spin_exit(&p->p_stmutex);
    229   1.1       cgd 		return (0);
    230   1.1       cgd 	}
    231   1.1       cgd 	upp = &p->p_stats->p_prof;
    232   1.1       cgd 
    233   1.1       cgd 	/* Block profile interrupts while changing state. */
    234  1.38        ad 	mutex_spin_enter(&p->p_stmutex);
    235   1.4       cgd 	upp->pr_off = SCARG(uap, offset);
    236   1.4       cgd 	upp->pr_scale = SCARG(uap, scale);
    237   1.4       cgd 	upp->pr_base = SCARG(uap, samples);
    238   1.4       cgd 	upp->pr_size = SCARG(uap, size);
    239   1.1       cgd 	startprofclock(p);
    240  1.38        ad 	mutex_spin_exit(&p->p_stmutex);
    241   1.1       cgd 
    242   1.1       cgd 	return (0);
    243   1.1       cgd }
    244   1.1       cgd 
    245   1.1       cgd /*
    246   1.1       cgd  * Scale is a fixed-point number with the binary point 16 bits
    247   1.1       cgd  * into the value, and is <= 1.0.  pc is at most 32 bits, so the
    248   1.1       cgd  * intermediate result is at most 48 bits.
    249   1.1       cgd  */
    250   1.1       cgd #define	PC_TO_INDEX(pc, prof) \
    251   1.1       cgd 	((int)(((u_quad_t)((pc) - (prof)->pr_off) * \
    252   1.1       cgd 	    (u_quad_t)((prof)->pr_scale)) >> 16) & ~1)
    253   1.1       cgd 
    254   1.1       cgd /*
    255   1.1       cgd  * Collect user-level profiling statistics; called on a profiling tick,
    256   1.1       cgd  * when a process is running in user-mode.  This routine may be called
    257   1.1       cgd  * from an interrupt context.  We try to update the user profiling buffers
    258   1.1       cgd  * cheaply with fuswintr() and suswintr().  If that fails, we revert to
    259   1.1       cgd  * an AST that will vector us to trap() with a context in which copyin
    260   1.1       cgd  * and copyout will work.  Trap will then call addupc_task().
    261   1.1       cgd  *
    262   1.1       cgd  * Note that we may (rarely) not get around to the AST soon enough, and
    263   1.1       cgd  * lose profile ticks when the next tick overwrites this one, but in this
    264   1.1       cgd  * case the system is overloaded and the profile is probably already
    265   1.1       cgd  * inaccurate.
    266   1.1       cgd  */
    267   1.1       cgd void
    268  1.38        ad addupc_intr(struct lwp *l, u_long pc)
    269   1.1       cgd {
    270  1.20  augustss 	struct uprof *prof;
    271  1.38        ad 	struct proc *p;
    272  1.39  christos 	void *addr;
    273  1.20  augustss 	u_int i;
    274  1.20  augustss 	int v;
    275   1.1       cgd 
    276  1.38        ad 	p = l->l_proc;
    277  1.38        ad 
    278  1.41        ad 	KASSERT(mutex_owned(&p->p_stmutex));
    279  1.38        ad 
    280   1.1       cgd 	prof = &p->p_stats->p_prof;
    281   1.1       cgd 	if (pc < prof->pr_off ||
    282   1.1       cgd 	    (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
    283   1.1       cgd 		return;			/* out of range; ignore */
    284   1.1       cgd 
    285  1.40  drochner 	addr = prof->pr_base + i;
    286  1.38        ad 	mutex_spin_exit(&p->p_stmutex);
    287  1.22   mycroft 	if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + 1) == -1) {
    288  1.38        ad 		/* XXXSMP */
    289   1.1       cgd 		prof->pr_addr = pc;
    290  1.22   mycroft 		prof->pr_ticks++;
    291  1.38        ad 		cpu_need_proftick(l);
    292   1.1       cgd 	}
    293  1.38        ad 	mutex_spin_enter(&p->p_stmutex);
    294   1.1       cgd }
    295   1.1       cgd 
    296   1.1       cgd /*
    297   1.1       cgd  * Much like before, but we can afford to take faults here.  If the
    298   1.1       cgd  * update fails, we simply turn off profiling.
    299   1.1       cgd  */
    300   1.1       cgd void
    301  1.38        ad addupc_task(struct lwp *l, u_long pc, u_int ticks)
    302   1.1       cgd {
    303  1.20  augustss 	struct uprof *prof;
    304  1.38        ad 	struct proc *p;
    305  1.39  christos 	void *addr;
    306  1.38        ad 	int error;
    307  1.20  augustss 	u_int i;
    308   1.1       cgd 	u_short v;
    309   1.1       cgd 
    310  1.38        ad 	p = l->l_proc;
    311  1.38        ad 
    312  1.38        ad 	if (ticks == 0)
    313   1.1       cgd 		return;
    314   1.1       cgd 
    315  1.38        ad 	mutex_spin_enter(&p->p_stmutex);
    316   1.1       cgd 	prof = &p->p_stats->p_prof;
    317  1.38        ad 
    318  1.38        ad 	/* Testing P_PROFIL may be unnecessary, but is certainly safe. */
    319  1.38        ad 	if ((p->p_stflag & PST_PROFIL) == 0 || pc < prof->pr_off ||
    320  1.38        ad 	    (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) {
    321  1.38        ad 		mutex_spin_exit(&p->p_stmutex);
    322   1.1       cgd 		return;
    323  1.38        ad 	}
    324   1.1       cgd 
    325  1.40  drochner 	addr = prof->pr_base + i;
    326  1.38        ad 	mutex_spin_exit(&p->p_stmutex);
    327  1.39  christos 	if ((error = copyin(addr, (void *)&v, sizeof(v))) == 0) {
    328   1.1       cgd 		v += ticks;
    329  1.39  christos 		error = copyout((void *)&v, addr, sizeof(v));
    330  1.38        ad 	}
    331  1.38        ad 	if (error != 0) {
    332  1.38        ad 		mutex_spin_enter(&p->p_stmutex);
    333  1.38        ad 		stopprofclock(p);
    334  1.38        ad 		mutex_spin_exit(&p->p_stmutex);
    335   1.1       cgd 	}
    336   1.1       cgd }
    337