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31 * @(#)subr_prof.c 8.3 (Berkeley) 9/23/93
34 #include <sys/cdefs.h>
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/sysproto.h>
38 #include <sys/kernel.h>
40 #include <sys/mutex.h>
42 #include <sys/resourcevar.h>
43 #include <sys/sysctl.h>
45 #include <machine/cpu.h>
48 * Profiling system call.
50 * The scale factor is a fixed point number with 16 bits of fraction, so that
51 * 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling.
53 #ifndef _SYS_SYSPROTO_H_
63 sys_profil(struct thread *td, struct profil_args *uap)
68 if (uap->scale > (1 << 16))
72 if (uap->scale == 0) {
79 upp = &td->td_proc->p_stats->p_prof;
81 upp->pr_off = uap->offset;
82 upp->pr_scale = uap->scale;
83 upp->pr_base = uap->samples;
84 upp->pr_size = uap->size;
93 * Scale is a fixed-point number with the binary point 16 bits
94 * into the value, and is <= 1.0. pc is at most 32 bits, so the
95 * intermediate result is at most 48 bits.
97 #define PC_TO_INDEX(pc, prof) \
98 ((int)(((u_quad_t)((pc) - (prof)->pr_off) * \
99 (u_quad_t)((prof)->pr_scale)) >> 16) & ~1)
102 * Collect user-level profiling statistics; called on a profiling tick,
103 * when a process is running in user-mode. This routine may be called
104 * from an interrupt context. We perform the update with an AST
105 * that will vector us to trap() with a context in which copyin and
106 * copyout will work. Trap will then call addupc_task().
108 * Note that we may (rarely) not get around to the AST soon enough, and
109 * lose profile ticks when the next tick overwrites this one, but in this
110 * case the system is overloaded and the profile is probably already
114 addupc_intr(struct thread *td, uintfptr_t pc, u_int ticks)
120 prof = &td->td_proc->p_stats->p_prof;
121 PROC_PROFLOCK(td->td_proc);
122 if (pc < prof->pr_off || PC_TO_INDEX(pc, prof) >= prof->pr_size) {
123 PROC_PROFUNLOCK(td->td_proc);
124 return; /* out of range; ignore */
127 PROC_PROFUNLOCK(td->td_proc);
128 td->td_profil_addr = pc;
129 td->td_profil_ticks = ticks;
130 td->td_pflags |= TDP_OWEUPC;
131 ast_sched(td, TDA_OWEUPC);
135 * Actually update the profiling statistics. If the update fails, we
136 * simply turn off profiling.
139 addupc_task(struct thread *td, uintfptr_t pc, u_int ticks)
141 struct proc *p = td->td_proc;
152 if (!(p->p_flag & P_PROFIL)) {
157 prof = &p->p_stats->p_prof;
159 if (pc < prof->pr_off ||
160 (i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) {
165 addr = prof->pr_base + i;
168 if (copyin(addr, &v, sizeof(v)) == 0) {
170 if (copyout(&v, addr, sizeof(v)) == 0) {
179 if (--p->p_profthreads == 0) {
180 if (p->p_flag & P_STOPPROF) {
181 wakeup(&p->p_profthreads);
182 p->p_flag &= ~P_STOPPROF;