/* $NetBSD: tprof.c,v 1.21.2.2 2023/06/21 22:34:51 martin Exp $ */ /*- * Copyright (c)2008,2009,2010 YAMAMOTO Takashi, * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __KERNEL_RCSID(0, "$NetBSD: tprof.c,v 1.21.2.2 2023/06/21 22:34:51 martin Exp $"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "ioconf.h" #ifndef TPROF_HZ #define TPROF_HZ 10000 #endif /* * locking order: * tprof_reader_lock -> tprof_lock * tprof_startstop_lock -> tprof_lock */ /* * protected by: * L: tprof_lock * R: tprof_reader_lock * S: tprof_startstop_lock * s: writer should hold tprof_startstop_lock and tprof_lock * reader should hold tprof_startstop_lock or tprof_lock */ typedef struct tprof_buf { u_int b_used; u_int b_size; u_int b_overflow; u_int b_unused; STAILQ_ENTRY(tprof_buf) b_list; tprof_sample_t b_data[]; } tprof_buf_t; #define TPROF_BUF_BYTESIZE(sz) \ (sizeof(tprof_buf_t) + (sz) * sizeof(tprof_sample_t)) #define TPROF_MAX_SAMPLES_PER_BUF TPROF_HZ typedef struct { tprof_buf_t *c_buf; uint32_t c_cpuid; struct work c_work; callout_t c_callout; } __aligned(CACHE_LINE_SIZE) tprof_cpu_t; typedef struct tprof_backend { /* * tprof_backend_softc_t must be passed as an argument to the interrupt * handler, but since this is difficult to implement in armv7/v8. Then, * tprof_backend is exposed. Additionally, softc must be placed at the * beginning of struct tprof_backend. */ tprof_backend_softc_t tb_softc; const char *tb_name; const tprof_backend_ops_t *tb_ops; LIST_ENTRY(tprof_backend) tb_list; } tprof_backend_t; static kmutex_t tprof_lock; static u_int tprof_nworker; /* L: # of running worker LWPs */ static lwp_t *tprof_owner; static STAILQ_HEAD(, tprof_buf) tprof_list; /* L: global buffer list */ static u_int tprof_nbuf_on_list; /* L: # of buffers on tprof_list */ static struct workqueue *tprof_wq; static struct percpu *tprof_cpus __read_mostly; /* tprof_cpu_t * */ static u_int tprof_samples_per_buf; static u_int tprof_max_buf; tprof_backend_t *tprof_backend; /* S: */ static LIST_HEAD(, tprof_backend) tprof_backends = LIST_HEAD_INITIALIZER(tprof_backend); /* S: */ static kmutex_t tprof_reader_lock; static kcondvar_t tprof_reader_cv; /* L: */ static off_t tprof_reader_offset; /* R: */ static kmutex_t tprof_startstop_lock; static kcondvar_t tprof_cv; /* L: */ static struct selinfo tprof_selp; /* L: */ static struct tprof_stat tprof_stat; /* L: */ static tprof_cpu_t * tprof_cpu_direct(struct cpu_info *ci) { tprof_cpu_t **cp; cp = percpu_getptr_remote(tprof_cpus, ci); return *cp; } static tprof_cpu_t * tprof_cpu(struct cpu_info *ci) { tprof_cpu_t *c; /* * As long as xcalls are blocked -- e.g., by kpreempt_disable * -- the percpu object will not be swapped and destroyed. We * can't write to it, because the data may have already been * moved to a new buffer, but we can safely read from it. */ kpreempt_disable(); c = tprof_cpu_direct(ci); kpreempt_enable(); return c; } static tprof_cpu_t * tprof_curcpu(void) { return tprof_cpu(curcpu()); } static tprof_buf_t * tprof_buf_alloc(void) { tprof_buf_t *new; u_int size = tprof_samples_per_buf; new = kmem_alloc(TPROF_BUF_BYTESIZE(size), KM_SLEEP); new->b_used = 0; new->b_size = size; new->b_overflow = 0; return new; } static void tprof_buf_free(tprof_buf_t *buf) { kmem_free(buf, TPROF_BUF_BYTESIZE(buf->b_size)); } static tprof_buf_t * tprof_buf_switch(tprof_cpu_t *c, tprof_buf_t *new) { tprof_buf_t *old; old = c->c_buf; c->c_buf = new; return old; } static tprof_buf_t * tprof_buf_refresh(void) { tprof_cpu_t * const c = tprof_curcpu(); tprof_buf_t *new; new = tprof_buf_alloc(); return tprof_buf_switch(c, new); } static void tprof_worker(struct work *wk, void *dummy) { tprof_cpu_t * const c = tprof_curcpu(); tprof_buf_t *buf; tprof_backend_t *tb; bool shouldstop; KASSERT(wk == &c->c_work); KASSERT(dummy == NULL); /* * Get a per cpu buffer. */ buf = tprof_buf_refresh(); /* * and put it on the global list for read(2). */ mutex_enter(&tprof_lock); tb = tprof_backend; shouldstop = (tb == NULL || tb->tb_softc.sc_ctr_running_mask == 0); if (shouldstop) { KASSERT(tprof_nworker > 0); tprof_nworker--; cv_broadcast(&tprof_cv); cv_broadcast(&tprof_reader_cv); } if (buf->b_used == 0) { tprof_stat.ts_emptybuf++; } else if (tprof_nbuf_on_list < tprof_max_buf) { tprof_stat.ts_sample += buf->b_used; tprof_stat.ts_overflow += buf->b_overflow; tprof_stat.ts_buf++; STAILQ_INSERT_TAIL(&tprof_list, buf, b_list); tprof_nbuf_on_list++; buf = NULL; selnotify(&tprof_selp, 0, NOTE_SUBMIT); cv_broadcast(&tprof_reader_cv); } else { tprof_stat.ts_dropbuf_sample += buf->b_used; tprof_stat.ts_dropbuf++; } mutex_exit(&tprof_lock); if (buf) tprof_buf_free(buf); if (!shouldstop) callout_schedule(&c->c_callout, hz / 8); } static void tprof_kick(void *vp) { struct cpu_info * const ci = vp; tprof_cpu_t * const c = tprof_cpu(ci); workqueue_enqueue(tprof_wq, &c->c_work, ci); } static void tprof_stop1(void) { CPU_INFO_ITERATOR cii; struct cpu_info *ci; KASSERT(mutex_owned(&tprof_startstop_lock)); KASSERT(tprof_nworker == 0); for (CPU_INFO_FOREACH(cii, ci)) { tprof_cpu_t * const c = tprof_cpu(ci); tprof_buf_t *old; old = tprof_buf_switch(c, NULL); if (old != NULL) tprof_buf_free(old); callout_destroy(&c->c_callout); } workqueue_destroy(tprof_wq); } static void tprof_getinfo(struct tprof_info *info) { tprof_backend_t *tb; KASSERT(mutex_owned(&tprof_startstop_lock)); memset(info, 0, sizeof(*info)); info->ti_version = TPROF_VERSION; if ((tb = tprof_backend) != NULL) info->ti_ident = tb->tb_ops->tbo_ident(); } static int tprof_getncounters(u_int *ncounters) { tprof_backend_t *tb; tb = tprof_backend; if (tb == NULL) return ENOENT; *ncounters = tb->tb_ops->tbo_ncounters(); return 0; } static void tprof_start_cpu(void *arg1, void *arg2) { tprof_backend_t *tb = arg1; tprof_countermask_t runmask = (uintptr_t)arg2; tb->tb_ops->tbo_start(runmask); } static void tprof_stop_cpu(void *arg1, void *arg2) { tprof_backend_t *tb = arg1; tprof_countermask_t stopmask = (uintptr_t)arg2; tb->tb_ops->tbo_stop(stopmask); } static int tprof_start(tprof_countermask_t runmask) { CPU_INFO_ITERATOR cii; struct cpu_info *ci; tprof_backend_t *tb; uint64_t xc; int error; bool firstrun; KASSERT(mutex_owned(&tprof_startstop_lock)); tb = tprof_backend; if (tb == NULL) { error = ENOENT; goto done; } runmask &= ~tb->tb_softc.sc_ctr_running_mask; runmask &= tb->tb_softc.sc_ctr_configured_mask; if (runmask == 0) { /* * Targets are already running. * Unconfigured counters are ignored. */ error = 0; goto done; } firstrun = (tb->tb_softc.sc_ctr_running_mask == 0); if (firstrun) { if (tb->tb_ops->tbo_establish != NULL) { error = tb->tb_ops->tbo_establish(&tb->tb_softc); if (error != 0) goto done; } tprof_samples_per_buf = TPROF_MAX_SAMPLES_PER_BUF; tprof_max_buf = ncpu * 3; error = workqueue_create(&tprof_wq, "tprofmv", tprof_worker, NULL, PRI_NONE, IPL_SOFTCLOCK, WQ_MPSAFE | WQ_PERCPU); if (error != 0) { if (tb->tb_ops->tbo_disestablish != NULL) tb->tb_ops->tbo_disestablish(&tb->tb_softc); goto done; } for (CPU_INFO_FOREACH(cii, ci)) { tprof_cpu_t * const c = tprof_cpu(ci); tprof_buf_t *new; tprof_buf_t *old; new = tprof_buf_alloc(); old = tprof_buf_switch(c, new); if (old != NULL) { tprof_buf_free(old); } callout_init(&c->c_callout, CALLOUT_MPSAFE); callout_setfunc(&c->c_callout, tprof_kick, ci); } } runmask &= tb->tb_softc.sc_ctr_configured_mask; xc = xc_broadcast(0, tprof_start_cpu, tb, (void *)(uintptr_t)runmask); xc_wait(xc); mutex_enter(&tprof_lock); tb->tb_softc.sc_ctr_running_mask |= runmask; mutex_exit(&tprof_lock); if (firstrun) { for (CPU_INFO_FOREACH(cii, ci)) { tprof_cpu_t * const c = tprof_cpu(ci); mutex_enter(&tprof_lock); tprof_nworker++; mutex_exit(&tprof_lock); workqueue_enqueue(tprof_wq, &c->c_work, ci); } } error = 0; done: return error; } static void tprof_stop(tprof_countermask_t stopmask) { tprof_backend_t *tb; uint64_t xc; tb = tprof_backend; if (tb == NULL) return; KASSERT(mutex_owned(&tprof_startstop_lock)); stopmask &= tb->tb_softc.sc_ctr_running_mask; if (stopmask == 0) { /* Targets are not running */ goto done; } xc = xc_broadcast(0, tprof_stop_cpu, tb, (void *)(uintptr_t)stopmask); xc_wait(xc); mutex_enter(&tprof_lock); tb->tb_softc.sc_ctr_running_mask &= ~stopmask; mutex_exit(&tprof_lock); /* All counters have stopped? */ if (tb->tb_softc.sc_ctr_running_mask == 0) { mutex_enter(&tprof_lock); cv_broadcast(&tprof_reader_cv); while (tprof_nworker > 0) cv_wait(&tprof_cv, &tprof_lock); mutex_exit(&tprof_lock); tprof_stop1(); if (tb->tb_ops->tbo_disestablish != NULL) tb->tb_ops->tbo_disestablish(&tb->tb_softc); } done: ; } static void tprof_init_percpu_counters_offset(void *vp, void *vp2, struct cpu_info *ci) { uint64_t *counters_offset = vp; u_int counter = (uintptr_t)vp2; tprof_backend_t *tb = tprof_backend; tprof_param_t *param = &tb->tb_softc.sc_count[counter].ctr_param; counters_offset[counter] = param->p_value; } static void tprof_configure_event_cpu(void *arg1, void *arg2) { tprof_backend_t *tb = arg1; u_int counter = (uintptr_t)arg2; tprof_param_t *param = &tb->tb_softc.sc_count[counter].ctr_param; tb->tb_ops->tbo_configure_event(counter, param); } static int tprof_configure_event(const tprof_param_t *param) { tprof_backend_t *tb; tprof_backend_softc_t *sc; tprof_param_t *sc_param; uint64_t xc; int c, error; if ((param->p_flags & (TPROF_PARAM_USER | TPROF_PARAM_KERN)) == 0) { error = EINVAL; goto done; } tb = tprof_backend; if (tb == NULL) { error = ENOENT; goto done; } sc = &tb->tb_softc; c = param->p_counter; if (c >= tb->tb_softc.sc_ncounters) { error = EINVAL; goto done; } if (tb->tb_ops->tbo_valid_event != NULL) { error = tb->tb_ops->tbo_valid_event(param->p_counter, param); if (error != 0) goto done; } /* if already running, stop the counter */ if (ISSET(c, tb->tb_softc.sc_ctr_running_mask)) tprof_stop(__BIT(c)); sc->sc_count[c].ctr_bitwidth = tb->tb_ops->tbo_counter_bitwidth(param->p_counter); sc_param = &sc->sc_count[c].ctr_param; memcpy(sc_param, param, sizeof(*sc_param)); /* save copy of param */ if (ISSET(param->p_flags, TPROF_PARAM_PROFILE)) { uint64_t freq, inum, dnum; freq = tb->tb_ops->tbo_counter_estimate_freq(c); sc->sc_count[c].ctr_counter_val = freq / TPROF_HZ; if (sc->sc_count[c].ctr_counter_val == 0) { printf("%s: counter#%d frequency (%"PRIu64") is" " very low relative to TPROF_HZ (%u)\n", __func__, c, freq, TPROF_HZ); sc->sc_count[c].ctr_counter_val = 4000000000ULL / TPROF_HZ; } switch (param->p_flags & TPROF_PARAM_VALUE2_MASK) { case TPROF_PARAM_VALUE2_SCALE: if (sc_param->p_value2 == 0) break; /* * p_value2 is 64-bit fixed-point * upper 32 bits are the integer part * lower 32 bits are the decimal part */ inum = sc_param->p_value2 >> 32; dnum = sc_param->p_value2 & __BITS(31, 0); sc->sc_count[c].ctr_counter_val = sc->sc_count[c].ctr_counter_val * inum + (sc->sc_count[c].ctr_counter_val * dnum >> 32); if (sc->sc_count[c].ctr_counter_val == 0) sc->sc_count[c].ctr_counter_val = 1; break; case TPROF_PARAM_VALUE2_TRIGGERCOUNT: if (sc_param->p_value2 == 0) sc_param->p_value2 = 1; if (sc_param->p_value2 > __BITS(sc->sc_count[c].ctr_bitwidth - 1, 0)) { sc_param->p_value2 = __BITS(sc->sc_count[c].ctr_bitwidth - 1, 0); } sc->sc_count[c].ctr_counter_val = sc_param->p_value2; break; default: break; } sc->sc_count[c].ctr_counter_reset_val = -sc->sc_count[c].ctr_counter_val; sc->sc_count[c].ctr_counter_reset_val &= __BITS(sc->sc_count[c].ctr_bitwidth - 1, 0); } else { sc->sc_count[c].ctr_counter_val = 0; sc->sc_count[c].ctr_counter_reset_val = 0; } /* At this point, p_value is used as an initial value */ percpu_foreach(tb->tb_softc.sc_ctr_offset_percpu, tprof_init_percpu_counters_offset, (void *)(uintptr_t)c); /* On the backend side, p_value is used as the reset value */ sc_param->p_value = tb->tb_softc.sc_count[c].ctr_counter_reset_val; xc = xc_broadcast(0, tprof_configure_event_cpu, tb, (void *)(uintptr_t)c); xc_wait(xc); mutex_enter(&tprof_lock); /* update counters bitmasks */ SET(tb->tb_softc.sc_ctr_configured_mask, __BIT(c)); CLR(tb->tb_softc.sc_ctr_prof_mask, __BIT(c)); CLR(tb->tb_softc.sc_ctr_ovf_mask, __BIT(c)); /* profiled counter requires overflow handling */ if (ISSET(param->p_flags, TPROF_PARAM_PROFILE)) { SET(tb->tb_softc.sc_ctr_prof_mask, __BIT(c)); SET(tb->tb_softc.sc_ctr_ovf_mask, __BIT(c)); } /* counters with less than 64bits also require overflow handling */ if (sc->sc_count[c].ctr_bitwidth != 64) SET(tb->tb_softc.sc_ctr_ovf_mask, __BIT(c)); mutex_exit(&tprof_lock); error = 0; done: return error; } static void tprof_getcounts_cpu(void *arg1, void *arg2) { tprof_backend_t *tb = arg1; tprof_backend_softc_t *sc = &tb->tb_softc; uint64_t *counters = arg2; uint64_t *counters_offset; unsigned int c; tprof_countermask_t configmask = sc->sc_ctr_configured_mask; counters_offset = percpu_getref(sc->sc_ctr_offset_percpu); for (c = 0; c < sc->sc_ncounters; c++) { if (ISSET(configmask, __BIT(c))) { uint64_t ctr = tb->tb_ops->tbo_counter_read(c); counters[c] = counters_offset[c] + ((ctr - sc->sc_count[c].ctr_counter_reset_val) & __BITS(sc->sc_count[c].ctr_bitwidth - 1, 0)); } else counters[c] = 0; } percpu_putref(sc->sc_ctr_offset_percpu); } static int tprof_getcounts(tprof_counts_t *counts) { struct cpu_info *ci; tprof_backend_t *tb; uint64_t xc; tb = tprof_backend; if (tb == NULL) return ENOENT; if (counts->c_cpu >= ncpu) return ESRCH; ci = cpu_lookup(counts->c_cpu); if (ci == NULL) return ESRCH; xc = xc_unicast(0, tprof_getcounts_cpu, tb, counts->c_count, ci); xc_wait(xc); counts->c_ncounters = tb->tb_softc.sc_ncounters; counts->c_runningmask = tb->tb_softc.sc_ctr_running_mask; return 0; } /* * tprof_clear: drain unread samples. */ static void tprof_clear(void) { tprof_buf_t *buf; mutex_enter(&tprof_reader_lock); mutex_enter(&tprof_lock); while ((buf = STAILQ_FIRST(&tprof_list)) != NULL) { if (buf != NULL) { STAILQ_REMOVE_HEAD(&tprof_list, b_list); KASSERT(tprof_nbuf_on_list > 0); tprof_nbuf_on_list--; mutex_exit(&tprof_lock); tprof_buf_free(buf); mutex_enter(&tprof_lock); } } KASSERT(tprof_nbuf_on_list == 0); mutex_exit(&tprof_lock); tprof_reader_offset = 0; mutex_exit(&tprof_reader_lock); memset(&tprof_stat, 0, sizeof(tprof_stat)); } static tprof_backend_t * tprof_backend_lookup(const char *name) { tprof_backend_t *tb; KASSERT(mutex_owned(&tprof_startstop_lock)); LIST_FOREACH(tb, &tprof_backends, tb_list) { if (!strcmp(tb->tb_name, name)) { return tb; } } return NULL; } /* -------------------- backend interfaces */ /* * tprof_sample: record a sample on the per-cpu buffer. * * be careful; can be called in NMI context. * we are bluntly assuming the followings are safe. * curcpu() * curlwp->l_lid * curlwp->l_proc->p_pid */ void tprof_sample(void *unused, const tprof_frame_info_t *tfi) { tprof_cpu_t * const c = tprof_cpu_direct(curcpu()); tprof_buf_t * const buf = c->c_buf; tprof_sample_t *sp; const uintptr_t pc = tfi->tfi_pc; const lwp_t * const l = curlwp; u_int idx; idx = buf->b_used; if (__predict_false(idx >= buf->b_size)) { buf->b_overflow++; return; } sp = &buf->b_data[idx]; sp->s_pid = l->l_proc->p_pid; sp->s_lwpid = l->l_lid; sp->s_cpuid = c->c_cpuid; sp->s_flags = ((tfi->tfi_inkernel) ? TPROF_SAMPLE_INKERNEL : 0) | __SHIFTIN(tfi->tfi_counter, TPROF_SAMPLE_COUNTER_MASK); sp->s_pc = pc; buf->b_used = idx + 1; } /* * tprof_backend_register: */ int tprof_backend_register(const char *name, const tprof_backend_ops_t *ops, int vers) { tprof_backend_t *tb; if (vers != TPROF_BACKEND_VERSION) return EINVAL; mutex_enter(&tprof_startstop_lock); tb = tprof_backend_lookup(name); if (tb != NULL) { mutex_exit(&tprof_startstop_lock); return EEXIST; } #if 1 /* XXX for now */ if (!LIST_EMPTY(&tprof_backends)) { mutex_exit(&tprof_startstop_lock); return ENOTSUP; } #endif tb = kmem_zalloc(sizeof(*tb), KM_SLEEP); tb->tb_name = name; tb->tb_ops = ops; LIST_INSERT_HEAD(&tprof_backends, tb, tb_list); #if 1 /* XXX for now */ if (tprof_backend == NULL) { tprof_backend = tb; } #endif mutex_exit(&tprof_startstop_lock); /* Init backend softc */ tb->tb_softc.sc_ncounters = tb->tb_ops->tbo_ncounters(); tb->tb_softc.sc_ctr_offset_percpu_size = sizeof(uint64_t) * tb->tb_softc.sc_ncounters; tb->tb_softc.sc_ctr_offset_percpu = percpu_alloc(tb->tb_softc.sc_ctr_offset_percpu_size); return 0; } /* * tprof_backend_unregister: */ int tprof_backend_unregister(const char *name) { tprof_backend_t *tb; mutex_enter(&tprof_startstop_lock); tb = tprof_backend_lookup(name); #if defined(DIAGNOSTIC) if (tb == NULL) { mutex_exit(&tprof_startstop_lock); panic("%s: not found '%s'", __func__, name); } #endif /* defined(DIAGNOSTIC) */ if (tb->tb_softc.sc_ctr_running_mask != 0) { mutex_exit(&tprof_startstop_lock); return EBUSY; } #if 1 /* XXX for now */ if (tprof_backend == tb) tprof_backend = NULL; #endif LIST_REMOVE(tb, tb_list); mutex_exit(&tprof_startstop_lock); /* fini backend softc */ percpu_free(tb->tb_softc.sc_ctr_offset_percpu, tb->tb_softc.sc_ctr_offset_percpu_size); /* Free backend */ kmem_free(tb, sizeof(*tb)); return 0; } /* -------------------- cdevsw interfaces */ static int tprof_open(dev_t dev, int flags, int type, struct lwp *l) { if (minor(dev) != 0) return EXDEV; mutex_enter(&tprof_lock); if (tprof_owner != NULL) { mutex_exit(&tprof_lock); return EBUSY; } tprof_owner = curlwp; mutex_exit(&tprof_lock); return 0; } static int tprof_close(dev_t dev, int flags, int type, struct lwp *l) { KASSERT(minor(dev) == 0); mutex_enter(&tprof_startstop_lock); mutex_enter(&tprof_lock); tprof_owner = NULL; mutex_exit(&tprof_lock); tprof_stop(TPROF_COUNTERMASK_ALL); tprof_clear(); tprof_backend_t *tb = tprof_backend; if (tb != NULL) { KASSERT(tb->tb_softc.sc_ctr_running_mask == 0); tb->tb_softc.sc_ctr_configured_mask = 0; tb->tb_softc.sc_ctr_prof_mask = 0; tb->tb_softc.sc_ctr_ovf_mask = 0; } mutex_exit(&tprof_startstop_lock); return 0; } static int tprof_poll(dev_t dev, int events, struct lwp *l) { int revents; revents = events & (POLLIN | POLLRDNORM); if (revents == 0) return 0; mutex_enter(&tprof_lock); if (STAILQ_EMPTY(&tprof_list)) { revents = 0; selrecord(l, &tprof_selp); } mutex_exit(&tprof_lock); return revents; } static void filt_tprof_read_detach(struct knote *kn) { mutex_enter(&tprof_lock); selremove_knote(&tprof_selp, kn); mutex_exit(&tprof_lock); } static int filt_tprof_read_event(struct knote *kn, long hint) { int rv = 0; if ((hint & NOTE_SUBMIT) == 0) mutex_enter(&tprof_lock); if (!STAILQ_EMPTY(&tprof_list)) { tprof_buf_t *buf; int64_t n = 0; STAILQ_FOREACH(buf, &tprof_list, b_list) { n += buf->b_used; } kn->kn_data = n * sizeof(tprof_sample_t); rv = 1; } if ((hint & NOTE_SUBMIT) == 0) mutex_exit(&tprof_lock); return rv; } static const struct filterops tprof_read_filtops = { .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE, .f_attach = NULL, .f_detach = filt_tprof_read_detach, .f_event = filt_tprof_read_event, }; static int tprof_kqfilter(dev_t dev, struct knote *kn) { switch (kn->kn_filter) { case EVFILT_READ: kn->kn_fop = &tprof_read_filtops; mutex_enter(&tprof_lock); selrecord_knote(&tprof_selp, kn); mutex_exit(&tprof_lock); break; default: return EINVAL; } return 0; } static int tprof_read(dev_t dev, struct uio *uio, int flags) { tprof_buf_t *buf; size_t bytes; size_t resid; size_t done = 0; int error = 0; KASSERT(minor(dev) == 0); mutex_enter(&tprof_reader_lock); while (uio->uio_resid > 0 && error == 0) { /* * Take the first buffer from the list. */ mutex_enter(&tprof_lock); buf = STAILQ_FIRST(&tprof_list); if (buf == NULL) { if (tprof_nworker == 0 || done != 0) { mutex_exit(&tprof_lock); error = 0; break; } mutex_exit(&tprof_reader_lock); error = cv_wait_sig(&tprof_reader_cv, &tprof_lock); mutex_exit(&tprof_lock); mutex_enter(&tprof_reader_lock); continue; } STAILQ_REMOVE_HEAD(&tprof_list, b_list); KASSERT(tprof_nbuf_on_list > 0); tprof_nbuf_on_list--; mutex_exit(&tprof_lock); /* * Copy it out. */ bytes = MIN(buf->b_used * sizeof(tprof_sample_t) - tprof_reader_offset, uio->uio_resid); resid = uio->uio_resid; error = uiomove((char *)buf->b_data + tprof_reader_offset, bytes, uio); done = resid - uio->uio_resid; tprof_reader_offset += done; /* * If we didn't consume the whole buffer, * put it back to the list. */ if (tprof_reader_offset < buf->b_used * sizeof(tprof_sample_t)) { mutex_enter(&tprof_lock); STAILQ_INSERT_HEAD(&tprof_list, buf, b_list); tprof_nbuf_on_list++; cv_broadcast(&tprof_reader_cv); mutex_exit(&tprof_lock); } else { tprof_buf_free(buf); tprof_reader_offset = 0; } } mutex_exit(&tprof_reader_lock); return error; } static int tprof_ioctl(dev_t dev, u_long cmd, void *data, int flags, struct lwp *l) { const tprof_param_t *param; tprof_counts_t *counts; int error = 0; KASSERT(minor(dev) == 0); switch (cmd) { case TPROF_IOC_GETINFO: mutex_enter(&tprof_startstop_lock); tprof_getinfo(data); mutex_exit(&tprof_startstop_lock); break; case TPROF_IOC_GETNCOUNTERS: mutex_enter(&tprof_lock); error = tprof_getncounters((u_int *)data); mutex_exit(&tprof_lock); break; case TPROF_IOC_START: mutex_enter(&tprof_startstop_lock); error = tprof_start(*(tprof_countermask_t *)data); mutex_exit(&tprof_startstop_lock); break; case TPROF_IOC_STOP: mutex_enter(&tprof_startstop_lock); tprof_stop(*(tprof_countermask_t *)data); mutex_exit(&tprof_startstop_lock); break; case TPROF_IOC_GETSTAT: mutex_enter(&tprof_lock); memcpy(data, &tprof_stat, sizeof(tprof_stat)); mutex_exit(&tprof_lock); break; case TPROF_IOC_CONFIGURE_EVENT: param = data; mutex_enter(&tprof_startstop_lock); error = tprof_configure_event(param); mutex_exit(&tprof_startstop_lock); break; case TPROF_IOC_GETCOUNTS: counts = data; mutex_enter(&tprof_startstop_lock); error = tprof_getcounts(counts); mutex_exit(&tprof_startstop_lock); break; default: error = EINVAL; break; } return error; } const struct cdevsw tprof_cdevsw = { .d_open = tprof_open, .d_close = tprof_close, .d_read = tprof_read, .d_write = nowrite, .d_ioctl = tprof_ioctl, .d_stop = nostop, .d_tty = notty, .d_poll = tprof_poll, .d_mmap = nommap, .d_kqfilter = tprof_kqfilter, .d_discard = nodiscard, .d_flag = D_OTHER | D_MPSAFE }; void tprofattach(int nunits) { /* Nothing */ } MODULE(MODULE_CLASS_DRIVER, tprof, NULL); static void tprof_cpu_init(void *vcp, void *vcookie, struct cpu_info *ci) { tprof_cpu_t **cp = vcp, *c; c = kmem_zalloc(sizeof(*c), KM_SLEEP); c->c_buf = NULL; c->c_cpuid = cpu_index(ci); *cp = c; } static void tprof_cpu_fini(void *vcp, void *vcookie, struct cpu_info *ci) { tprof_cpu_t **cp = vcp, *c; c = *cp; KASSERT(c->c_cpuid == cpu_index(ci)); KASSERT(c->c_buf == NULL); kmem_free(c, sizeof(*c)); *cp = NULL; } static void tprof_driver_init(void) { mutex_init(&tprof_lock, MUTEX_DEFAULT, IPL_NONE); mutex_init(&tprof_reader_lock, MUTEX_DEFAULT, IPL_NONE); mutex_init(&tprof_startstop_lock, MUTEX_DEFAULT, IPL_NONE); selinit(&tprof_selp); cv_init(&tprof_cv, "tprof"); cv_init(&tprof_reader_cv, "tprof_rd"); STAILQ_INIT(&tprof_list); tprof_cpus = percpu_create(sizeof(tprof_cpu_t *), tprof_cpu_init, tprof_cpu_fini, NULL); } static void tprof_driver_fini(void) { percpu_free(tprof_cpus, sizeof(tprof_cpu_t *)); mutex_destroy(&tprof_lock); mutex_destroy(&tprof_reader_lock); mutex_destroy(&tprof_startstop_lock); seldestroy(&tprof_selp); cv_destroy(&tprof_cv); cv_destroy(&tprof_reader_cv); } static int tprof_modcmd(modcmd_t cmd, void *arg) { switch (cmd) { case MODULE_CMD_INIT: tprof_driver_init(); #if defined(_MODULE) { devmajor_t bmajor = NODEVMAJOR; devmajor_t cmajor = NODEVMAJOR; int error; error = devsw_attach("tprof", NULL, &bmajor, &tprof_cdevsw, &cmajor); if (error) { tprof_driver_fini(); return error; } } #endif /* defined(_MODULE) */ return 0; case MODULE_CMD_FINI: #if defined(_MODULE) devsw_detach(NULL, &tprof_cdevsw); #endif /* defined(_MODULE) */ tprof_driver_fini(); return 0; default: return ENOTTY; } }