1179193Sjb/* 2179193Sjb * CDDL HEADER START 3179193Sjb * 4179193Sjb * The contents of this file are subject to the terms of the 5179193Sjb * Common Development and Distribution License (the "License"). 6179193Sjb * You may not use this file except in compliance with the License. 7179193Sjb * 8179193Sjb * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9179193Sjb * or http://www.opensolaris.org/os/licensing. 10179193Sjb * See the License for the specific language governing permissions 11179193Sjb * and limitations under the License. 12179193Sjb * 13179193Sjb * When distributing Covered Code, include this CDDL HEADER in each 14179193Sjb * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15179193Sjb * If applicable, add the following below this CDDL HEADER, with the 16179193Sjb * fields enclosed by brackets "[]" replaced with your own identifying 17179193Sjb * information: Portions Copyright [yyyy] [name of copyright owner] 18179193Sjb * 19179193Sjb * CDDL HEADER END 20179193Sjb */ 21179193Sjb/* 22179193Sjb * Copyright 2008 Sun Microsystems, Inc. All rights reserved. 23179193Sjb * Use is subject to license terms. 24179193Sjb */ 25179193Sjb 26179193Sjb#pragma ident "%Z%%M% %I% %E% SMI" 27179193Sjb 28179193Sjb#include <sys/types.h> 29179193Sjb#include <sys/param.h> 30179193Sjb#include <sys/stat.h> 31179193Sjb#include <sys/open.h> 32179193Sjb#include <sys/file.h> 33179193Sjb#include <sys/conf.h> 34179193Sjb#include <sys/modctl.h> 35179193Sjb#include <sys/cmn_err.h> 36179193Sjb#include <sys/bitmap.h> 37179193Sjb#include <sys/debug.h> 38179193Sjb#include <sys/kmem.h> 39179193Sjb#include <sys/errno.h> 40179193Sjb#include <sys/sysmacros.h> 41179193Sjb#include <sys/lockstat.h> 42179193Sjb#include <sys/atomic.h> 43179193Sjb#include <sys/dtrace.h> 44179193Sjb 45179193Sjb#include <sys/ddi.h> 46179193Sjb#include <sys/sunddi.h> 47179193Sjb 48179193Sjbtypedef struct lockstat_probe { 49179193Sjb const char *lsp_func; 50179193Sjb const char *lsp_name; 51179193Sjb int lsp_probe; 52179193Sjb dtrace_id_t lsp_id; 53179193Sjb} lockstat_probe_t; 54179193Sjb 55179193Sjblockstat_probe_t lockstat_probes[] = 56179193Sjb{ 57179193Sjb { LS_MUTEX_ENTER, LSA_ACQUIRE, LS_MUTEX_ENTER_ACQUIRE }, 58179193Sjb { LS_MUTEX_ENTER, LSA_BLOCK, LS_MUTEX_ENTER_BLOCK }, 59179193Sjb { LS_MUTEX_ENTER, LSA_SPIN, LS_MUTEX_ENTER_SPIN }, 60179193Sjb { LS_MUTEX_EXIT, LSA_RELEASE, LS_MUTEX_EXIT_RELEASE }, 61179193Sjb { LS_MUTEX_DESTROY, LSA_RELEASE, LS_MUTEX_DESTROY_RELEASE }, 62179193Sjb { LS_MUTEX_TRYENTER, LSA_ACQUIRE, LS_MUTEX_TRYENTER_ACQUIRE }, 63179193Sjb { LS_LOCK_SET, LSS_ACQUIRE, LS_LOCK_SET_ACQUIRE }, 64179193Sjb { LS_LOCK_SET, LSS_SPIN, LS_LOCK_SET_SPIN }, 65179193Sjb { LS_LOCK_SET_SPL, LSS_ACQUIRE, LS_LOCK_SET_SPL_ACQUIRE }, 66179193Sjb { LS_LOCK_SET_SPL, LSS_SPIN, LS_LOCK_SET_SPL_SPIN }, 67179193Sjb { LS_LOCK_TRY, LSS_ACQUIRE, LS_LOCK_TRY_ACQUIRE }, 68179193Sjb { LS_LOCK_CLEAR, LSS_RELEASE, LS_LOCK_CLEAR_RELEASE }, 69179193Sjb { LS_LOCK_CLEAR_SPLX, LSS_RELEASE, LS_LOCK_CLEAR_SPLX_RELEASE }, 70179193Sjb { LS_CLOCK_UNLOCK, LSS_RELEASE, LS_CLOCK_UNLOCK_RELEASE }, 71179193Sjb { LS_RW_ENTER, LSR_ACQUIRE, LS_RW_ENTER_ACQUIRE }, 72179193Sjb { LS_RW_ENTER, LSR_BLOCK, LS_RW_ENTER_BLOCK }, 73179193Sjb { LS_RW_EXIT, LSR_RELEASE, LS_RW_EXIT_RELEASE }, 74179193Sjb { LS_RW_TRYENTER, LSR_ACQUIRE, LS_RW_TRYENTER_ACQUIRE }, 75179193Sjb { LS_RW_TRYUPGRADE, LSR_UPGRADE, LS_RW_TRYUPGRADE_UPGRADE }, 76179193Sjb { LS_RW_DOWNGRADE, LSR_DOWNGRADE, LS_RW_DOWNGRADE_DOWNGRADE }, 77179193Sjb { LS_THREAD_LOCK, LST_SPIN, LS_THREAD_LOCK_SPIN }, 78179193Sjb { LS_THREAD_LOCK_HIGH, LST_SPIN, LS_THREAD_LOCK_HIGH_SPIN }, 79179193Sjb { NULL } 80179193Sjb}; 81179193Sjb 82179193Sjbstatic dev_info_t *lockstat_devi; /* saved in xxattach() for xxinfo() */ 83179193Sjbstatic kmutex_t lockstat_test; /* for testing purposes only */ 84179193Sjbstatic dtrace_provider_id_t lockstat_id; 85179193Sjb 86179193Sjb/*ARGSUSED*/ 87179193Sjbstatic void 88179193Sjblockstat_enable(void *arg, dtrace_id_t id, void *parg) 89179193Sjb{ 90179193Sjb lockstat_probe_t *probe = parg; 91179193Sjb 92179193Sjb ASSERT(!lockstat_probemap[probe->lsp_probe]); 93179193Sjb 94179193Sjb lockstat_probemap[probe->lsp_probe] = id; 95179193Sjb membar_producer(); 96179193Sjb 97179193Sjb lockstat_hot_patch(); 98179193Sjb membar_producer(); 99179193Sjb 100179193Sjb /* 101179193Sjb * Immediately generate a record for the lockstat_test mutex 102179193Sjb * to verify that the mutex hot-patch code worked as expected. 103179193Sjb */ 104179193Sjb mutex_enter(&lockstat_test); 105179193Sjb mutex_exit(&lockstat_test); 106179193Sjb} 107179193Sjb 108179193Sjb/*ARGSUSED*/ 109179193Sjbstatic void 110179193Sjblockstat_disable(void *arg, dtrace_id_t id, void *parg) 111179193Sjb{ 112179193Sjb lockstat_probe_t *probe = parg; 113179193Sjb int i; 114179193Sjb 115179193Sjb ASSERT(lockstat_probemap[probe->lsp_probe]); 116179193Sjb 117179193Sjb lockstat_probemap[probe->lsp_probe] = 0; 118179193Sjb lockstat_hot_patch(); 119179193Sjb membar_producer(); 120179193Sjb 121179193Sjb /* 122179193Sjb * See if we have any probes left enabled. 123179193Sjb */ 124179193Sjb for (i = 0; i < LS_NPROBES; i++) { 125179193Sjb if (lockstat_probemap[i]) { 126179193Sjb /* 127179193Sjb * This probe is still enabled. We don't need to deal 128179193Sjb * with waiting for all threads to be out of the 129179193Sjb * lockstat critical sections; just return. 130179193Sjb */ 131179193Sjb return; 132179193Sjb } 133179193Sjb } 134179193Sjb 135179193Sjb /* 136179193Sjb * The delay() here isn't as cheesy as you might think. We don't 137179193Sjb * want to busy-loop in the kernel, so we have to give up the 138179193Sjb * CPU between calls to lockstat_active_threads(); that much is 139179193Sjb * obvious. But the reason it's a do..while loop rather than a 140179193Sjb * while loop is subtle. The memory barrier above guarantees that 141179193Sjb * no threads will enter the lockstat code from this point forward. 142179193Sjb * However, another thread could already be executing lockstat code 143179193Sjb * without our knowledge if the update to its t_lockstat field hasn't 144179193Sjb * cleared its CPU's store buffer. Delaying for one clock tick 145179193Sjb * guarantees that either (1) the thread will have *ample* time to 146179193Sjb * complete its work, or (2) the thread will be preempted, in which 147179193Sjb * case it will have to grab and release a dispatcher lock, which 148179193Sjb * will flush that CPU's store buffer. Either way we're covered. 149179193Sjb */ 150179193Sjb do { 151179193Sjb delay(1); 152179193Sjb } while (lockstat_active_threads()); 153179193Sjb} 154179193Sjb 155179193Sjb/*ARGSUSED*/ 156179193Sjbstatic int 157179193Sjblockstat_open(dev_t *devp, int flag, int otyp, cred_t *cred_p) 158179193Sjb{ 159179193Sjb return (0); 160179193Sjb} 161179193Sjb 162179193Sjb/* ARGSUSED */ 163179193Sjbstatic int 164179193Sjblockstat_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result) 165179193Sjb{ 166179193Sjb int error; 167179193Sjb 168179193Sjb switch (infocmd) { 169179193Sjb case DDI_INFO_DEVT2DEVINFO: 170179193Sjb *result = (void *) lockstat_devi; 171179193Sjb error = DDI_SUCCESS; 172179193Sjb break; 173179193Sjb case DDI_INFO_DEVT2INSTANCE: 174179193Sjb *result = (void *)0; 175179193Sjb error = DDI_SUCCESS; 176179193Sjb break; 177179193Sjb default: 178179193Sjb error = DDI_FAILURE; 179179193Sjb } 180179193Sjb return (error); 181179193Sjb} 182179193Sjb 183179193Sjb/*ARGSUSED*/ 184179193Sjbstatic void 185179193Sjblockstat_provide(void *arg, const dtrace_probedesc_t *desc) 186179193Sjb{ 187179193Sjb int i = 0; 188179193Sjb 189179193Sjb for (i = 0; lockstat_probes[i].lsp_func != NULL; i++) { 190179193Sjb lockstat_probe_t *probe = &lockstat_probes[i]; 191179193Sjb 192179193Sjb if (dtrace_probe_lookup(lockstat_id, "genunix", 193179193Sjb probe->lsp_func, probe->lsp_name) != 0) 194179193Sjb continue; 195179193Sjb 196179193Sjb ASSERT(!probe->lsp_id); 197179193Sjb probe->lsp_id = dtrace_probe_create(lockstat_id, 198179193Sjb "genunix", probe->lsp_func, probe->lsp_name, 199179193Sjb 1, probe); 200179193Sjb } 201179193Sjb} 202179193Sjb 203179193Sjb/*ARGSUSED*/ 204179193Sjbstatic void 205179193Sjblockstat_destroy(void *arg, dtrace_id_t id, void *parg) 206179193Sjb{ 207179193Sjb lockstat_probe_t *probe = parg; 208179193Sjb 209179193Sjb ASSERT(!lockstat_probemap[probe->lsp_probe]); 210179193Sjb probe->lsp_id = 0; 211179193Sjb} 212179193Sjb 213179193Sjbstatic dtrace_pattr_t lockstat_attr = { 214179193Sjb{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON }, 215179193Sjb{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN }, 216179193Sjb{ DTRACE_STABILITY_PRIVATE, DTRACE_STABILITY_PRIVATE, DTRACE_CLASS_UNKNOWN }, 217179193Sjb{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON }, 218179193Sjb{ DTRACE_STABILITY_EVOLVING, DTRACE_STABILITY_EVOLVING, DTRACE_CLASS_COMMON }, 219179193Sjb}; 220179193Sjb 221179193Sjbstatic dtrace_pops_t lockstat_pops = { 222179193Sjb lockstat_provide, 223179193Sjb NULL, 224179193Sjb lockstat_enable, 225179193Sjb lockstat_disable, 226179193Sjb NULL, 227179193Sjb NULL, 228179193Sjb NULL, 229179193Sjb NULL, 230179193Sjb NULL, 231179193Sjb lockstat_destroy 232179193Sjb}; 233179193Sjb 234179193Sjbstatic int 235179193Sjblockstat_attach(dev_info_t *devi, ddi_attach_cmd_t cmd) 236179193Sjb{ 237179193Sjb switch (cmd) { 238179193Sjb case DDI_ATTACH: 239179193Sjb break; 240179193Sjb case DDI_RESUME: 241179193Sjb return (DDI_SUCCESS); 242179193Sjb default: 243179193Sjb return (DDI_FAILURE); 244179193Sjb } 245179193Sjb 246179193Sjb if (ddi_create_minor_node(devi, "lockstat", S_IFCHR, 0, 247179193Sjb DDI_PSEUDO, 0) == DDI_FAILURE || 248179193Sjb dtrace_register("lockstat", &lockstat_attr, DTRACE_PRIV_KERNEL, 249179193Sjb NULL, &lockstat_pops, NULL, &lockstat_id) != 0) { 250179193Sjb ddi_remove_minor_node(devi, NULL); 251179193Sjb return (DDI_FAILURE); 252179193Sjb } 253179193Sjb 254179193Sjb lockstat_probe = dtrace_probe; 255179193Sjb membar_producer(); 256179193Sjb 257179193Sjb ddi_report_dev(devi); 258179193Sjb lockstat_devi = devi; 259179193Sjb return (DDI_SUCCESS); 260179193Sjb} 261179193Sjb 262179193Sjbstatic int 263179193Sjblockstat_detach(dev_info_t *devi, ddi_detach_cmd_t cmd) 264179193Sjb{ 265179193Sjb switch (cmd) { 266179193Sjb case DDI_DETACH: 267179193Sjb break; 268179193Sjb case DDI_SUSPEND: 269179193Sjb return (DDI_SUCCESS); 270179193Sjb default: 271179193Sjb return (DDI_FAILURE); 272179193Sjb } 273179193Sjb 274179193Sjb if (dtrace_unregister(lockstat_id) != 0) 275179193Sjb return (DDI_FAILURE); 276179193Sjb 277179193Sjb ddi_remove_minor_node(devi, NULL); 278179193Sjb return (DDI_SUCCESS); 279179193Sjb} 280179193Sjb 281179193Sjb/* 282179193Sjb * Configuration data structures 283179193Sjb */ 284179193Sjbstatic struct cb_ops lockstat_cb_ops = { 285179193Sjb lockstat_open, /* open */ 286179193Sjb nodev, /* close */ 287179193Sjb nulldev, /* strategy */ 288179193Sjb nulldev, /* print */ 289179193Sjb nodev, /* dump */ 290179193Sjb nodev, /* read */ 291179193Sjb nodev, /* write */ 292179193Sjb nodev, /* ioctl */ 293179193Sjb nodev, /* devmap */ 294179193Sjb nodev, /* mmap */ 295179193Sjb nodev, /* segmap */ 296179193Sjb nochpoll, /* poll */ 297179193Sjb ddi_prop_op, /* cb_prop_op */ 298179193Sjb 0, /* streamtab */ 299179193Sjb D_MP | D_NEW /* Driver compatibility flag */ 300179193Sjb}; 301179193Sjb 302179193Sjbstatic struct dev_ops lockstat_ops = { 303179193Sjb DEVO_REV, /* devo_rev, */ 304179193Sjb 0, /* refcnt */ 305179193Sjb lockstat_info, /* getinfo */ 306179193Sjb nulldev, /* identify */ 307179193Sjb nulldev, /* probe */ 308179193Sjb lockstat_attach, /* attach */ 309179193Sjb lockstat_detach, /* detach */ 310179193Sjb nulldev, /* reset */ 311179193Sjb &lockstat_cb_ops, /* cb_ops */ 312179193Sjb NULL, /* bus_ops */ 313179193Sjb}; 314179193Sjb 315179193Sjbstatic struct modldrv modldrv = { 316179193Sjb &mod_driverops, /* Type of module. This one is a driver */ 317179193Sjb "Lock Statistics %I%", /* name of module */ 318179193Sjb &lockstat_ops, /* driver ops */ 319179193Sjb}; 320179193Sjb 321179193Sjbstatic struct modlinkage modlinkage = { 322179193Sjb MODREV_1, (void *)&modldrv, NULL 323179193Sjb}; 324179193Sjb 325179193Sjbint 326179193Sjb_init(void) 327179193Sjb{ 328179193Sjb return (mod_install(&modlinkage)); 329179193Sjb} 330179193Sjb 331179193Sjbint 332179193Sjb_fini(void) 333179193Sjb{ 334179193Sjb return (mod_remove(&modlinkage)); 335179193Sjb} 336179193Sjb 337179193Sjbint 338179193Sjb_info(struct modinfo *modinfop) 339179193Sjb{ 340179193Sjb return (mod_info(&modlinkage, modinfop)); 341179193Sjb} 342