Rewrite dtrace lockstat from the Solaris version and simplify.
- Fix mutex_adaptive probes to use the right lockstat flags. - Install lockstat_probe_func on module load, not trace enable. - Use a more sensible memory barrier arrangement.
This commit is contained in:
riastradh
parent
b638ee77d7
commit
409555c5e2
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@ -1,4 +1,4 @@
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/* $NetBSD: lockstat.c,v 1.4 2015/03/08 04:13:46 christos Exp $ */
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/* $NetBSD: lockstat.c,v 1.5 2015/03/08 23:56:59 riastradh Exp $ */
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/*
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* CDDL HEADER START
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@ -19,167 +19,81 @@
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* information: Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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* Portions Copyright (c) 2008-2009 Stacey Son <sson@FreeBSD.org>
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*
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* $FreeBSD: src/sys/cddl/dev/lockstat/lockstat.c,v 1.2.2.1 2009/08/03 08:13:06 kensmith Exp $
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*
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*/
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/*
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* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
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* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
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* Use is subject to license terms.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: lockstat.c,v 1.5 2015/03/08 23:56:59 riastradh Exp $");
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/conf.h>
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#include <sys/kernel.h>
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#include <sys/limits.h>
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#include <sys/lock.h>
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#include <sys/linker.h>
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#include <sys/dtrace.h>
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#include <sys/module.h>
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#include <sys/mutex.h>
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#ifdef __NetBSD__
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#include <sys/atomic.h>
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#include <sys/systm.h>
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#include <sys/xcall.h>
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#endif
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#include <sys/dtrace.h>
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#ifdef __NetBSD__
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#include <dev/lockstat.h>
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#else
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#include <sys/lockstat.h>
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#endif
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#ifdef __NetBSD__
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#define ASSERT KASSERT
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#endif
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#if defined(__i386__) || defined(__amd64__) || defined(__arm__)
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#define LOCKSTAT_AFRAMES 1
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#else
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#error "architecture not supported"
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#endif
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#if defined(__FreeBSD__)
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static d_open_t lockstat_open;
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#elif defined(__NetBSD__) && 0
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static dev_type_open(lockstat_open);
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#endif
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static void lockstat_provide(void *, const dtrace_probedesc_t *);
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static void lockstat_destroy(void *, dtrace_id_t, void *);
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static int lockstat_enable(void *, dtrace_id_t, void *);
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static void lockstat_disable(void *, dtrace_id_t, void *);
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static void lockstat_load(void *);
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static int lockstat_unload(void);
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typedef struct lockstat_probe {
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const char *lsp_func;
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const char *lsp_name;
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int lsp_probe;
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dtrace_id_t lsp_id;
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#ifdef __FreeBSD__
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int lsp_frame;
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#endif
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} lockstat_probe_t;
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#if defined(__FreeBSD__)
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lockstat_probe_t lockstat_probes[] =
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{
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/* Spin Locks */
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{ LS_MTX_SPIN_LOCK, LSS_ACQUIRE, LS_MTX_SPIN_LOCK_ACQUIRE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_MTX_SPIN_LOCK, LSS_SPIN, LS_MTX_SPIN_LOCK_SPIN,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_MTX_SPIN_UNLOCK, LSS_RELEASE, LS_MTX_SPIN_UNLOCK_RELEASE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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/* Adaptive Locks */
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{ LS_MTX_LOCK, LSA_ACQUIRE, LS_MTX_LOCK_ACQUIRE,
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DTRACE_IDNONE, (LOCKSTAT_AFRAMES + 1) },
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{ LS_MTX_LOCK, LSA_BLOCK, LS_MTX_LOCK_BLOCK,
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DTRACE_IDNONE, (LOCKSTAT_AFRAMES + 1) },
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{ LS_MTX_LOCK, LSA_SPIN, LS_MTX_LOCK_SPIN,
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DTRACE_IDNONE, (LOCKSTAT_AFRAMES + 1) },
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{ LS_MTX_UNLOCK, LSA_RELEASE, LS_MTX_UNLOCK_RELEASE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_MTX_TRYLOCK, LSA_ACQUIRE, LS_MTX_TRYLOCK_ACQUIRE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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/* Reader/Writer Locks */
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{ LS_RW_RLOCK, LSR_ACQUIRE, LS_RW_RLOCK_ACQUIRE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_RW_RLOCK, LSR_BLOCK, LS_RW_RLOCK_BLOCK,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_RW_RLOCK, LSR_SPIN, LS_RW_RLOCK_SPIN,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_RW_RUNLOCK, LSR_RELEASE, LS_RW_RUNLOCK_RELEASE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_RW_WLOCK, LSR_ACQUIRE, LS_RW_WLOCK_ACQUIRE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_RW_WLOCK, LSR_BLOCK, LS_RW_WLOCK_BLOCK,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_RW_WLOCK, LSR_SPIN, LS_RW_WLOCK_SPIN,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_RW_WUNLOCK, LSR_RELEASE, LS_RW_WUNLOCK_RELEASE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_RW_TRYUPGRADE, LSR_UPGRADE, LS_RW_TRYUPGRADE_UPGRADE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_RW_DOWNGRADE, LSR_DOWNGRADE, LS_RW_DOWNGRADE_DOWNGRADE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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/* Shared/Exclusive Locks */
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{ LS_SX_SLOCK, LSX_ACQUIRE, LS_SX_SLOCK_ACQUIRE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_SX_SLOCK, LSX_BLOCK, LS_SX_SLOCK_BLOCK,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_SX_SLOCK, LSX_SPIN, LS_SX_SLOCK_SPIN,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_SX_SUNLOCK, LSX_RELEASE, LS_SX_SUNLOCK_RELEASE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_SX_XLOCK, LSX_ACQUIRE, LS_SX_XLOCK_ACQUIRE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_SX_XLOCK, LSX_BLOCK, LS_SX_XLOCK_BLOCK,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_SX_XLOCK, LSX_SPIN, LS_SX_XLOCK_SPIN,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_SX_XUNLOCK, LSX_RELEASE, LS_SX_XUNLOCK_RELEASE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_SX_TRYUPGRADE, LSX_UPGRADE, LS_SX_TRYUPGRADE_UPGRADE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ LS_SX_DOWNGRADE, LSX_DOWNGRADE, LS_SX_DOWNGRADE_DOWNGRADE,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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/* Thread Locks */
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{ LS_THREAD_LOCK, LST_SPIN, LS_THREAD_LOCK_SPIN,
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DTRACE_IDNONE, LOCKSTAT_AFRAMES },
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{ NULL }
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};
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#elif defined(__NetBSD__)
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lockstat_probe_t lockstat_probes[] = {
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{ "mutex_spin", "spin", LB_SPIN_MUTEX | LB_SPIN, 0 },
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{ "mutex_adaptive", "sleep", LB_SPIN_MUTEX | LB_SLEEP1, 0 },
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{ "mutex_adaptive", "spin", LB_SPIN_MUTEX | LB_SPIN, 0 },
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{ "mutex_adaptive", "sleep", LB_ADAPTIVE_MUTEX | LB_SLEEP1, 0 },
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{ "mutex_adaptive", "spin", LB_ADAPTIVE_MUTEX | LB_SPIN, 0 },
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{ "rwlock", "sleep_writer", LB_RWLOCK | LB_SLEEP1, 0 },
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{ "rwlock", "sleep_reader", LB_RWLOCK | LB_SLEEP2, 0 },
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{ "rwlock", "spin", LB_RWLOCK | LB_SPIN, 0 },
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{ "kernel", "spin", LB_KERNEL_LOCK | LB_SPIN, 0 },
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{ "lwp", "spin", LB_NOPREEMPT | LB_SPIN, 0 },
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};
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#else
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#error "OS not supported"
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#endif
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static dtrace_provider_id_t lockstat_id;
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#if defined(__FreeBSD__)
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static struct cdevsw lockstat_cdevsw = {
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.d_version = D_VERSION,
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.d_open = lockstat_open,
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.d_name = "lockstat",
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};
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/*ARGSUSED*/
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static int
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lockstat_enable(void *arg, dtrace_id_t id, void *parg)
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{
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lockstat_probe_t *probe = parg;
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static struct cdev *lockstat_cdev;
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#elif defined(__NetBSD__) && 0
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static struct cdevsw lockstat_cdevsw = {
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ASSERT(!lockstat_probemap[probe->lsp_probe]);
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lockstat_probemap[probe->lsp_probe] = id;
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return 0;
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}
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/*ARGSUSED*/
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static void
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lockstat_disable(void *arg, dtrace_id_t id __unused, void *parg)
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{
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lockstat_probe_t *probe = parg;
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ASSERT(lockstat_probemap[probe->lsp_probe]);
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lockstat_probemap[probe->lsp_probe] = 0;
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}
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static int
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lockstat_open(dev_t dev __unused, int flags __unused, int mode __unused,
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struct lwp *l __unused)
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{
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return 0;
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}
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static const struct cdevsw lockstat_cdevsw = {
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.d_open = lockstat_open,
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.d_close = noclose,
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.d_read = noread,
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.d_discard = nodiscard,
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.d_flag = D_OTHER,
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};
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#endif
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static dtrace_provider_id_t lockstat_id;
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/*ARGSUSED*/
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static int
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lockstat_enable(void *arg, dtrace_id_t id, void *parg)
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{
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lockstat_probe_t *probe = parg;
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ASSERT(!lockstat_probemap[probe->lsp_probe]);
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if (lockstat_probe_func == lockstat_probe_stub) {
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lockstat_probe_func = dtrace_probe;
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membar_producer();
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} else {
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ASSERT(lockstat_probe_func == dtrace_probe);
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}
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lockstat_probemap[probe->lsp_probe] = id;
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return 0;
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}
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/*ARGSUSED*/
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static void
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lockstat_disable(void *arg, dtrace_id_t id, void *parg)
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{
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lockstat_probe_t *probe = parg;
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int i;
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ASSERT(lockstat_probe_func == dtrace_probe);
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ASSERT(lockstat_probemap[probe->lsp_probe]);
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lockstat_probemap[probe->lsp_probe] = 0;
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membar_producer();
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/*
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* See if we have any probes left enabled.
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*/
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for (i = 0; i < LS_NPROBES; i++) {
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if (lockstat_probemap[i]) {
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/*
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* This probe is still enabled. We don't need to deal
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* with waiting for all threads to be out of the
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* lockstat critical sections; just return.
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*/
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return;
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}
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}
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lockstat_probe_func = lockstat_probe_stub;
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/*
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* Trigger some activity on all CPUs to make sure they're not
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* in lockstat any more.
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*/
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xc_wait(xc_broadcast(0, (void *)nullop, NULL, NULL));
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}
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#if defined(__FreeBSD__)
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/*ARGSUSED*/
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static int
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lockstat_open(struct cdev *dev __unused, int oflags __unused,
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int devtype __unused, struct thread *td __unused)
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{
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return (0);
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}
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#elif defined(__NetBSD__) && 0
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static int
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lockstat_open(dev_t dev __unused, int flags __unused, int mode __unused,
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struct lwp *l __unused)
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{
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return 0;
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}
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#endif
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/*ARGSUSED*/
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static void
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@ -283,15 +123,9 @@ lockstat_provide(void *arg, const dtrace_probedesc_t *desc)
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continue;
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ASSERT(!probe->lsp_id);
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#ifdef __FreeBSD__
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probe->lsp_id = dtrace_probe_create(lockstat_id,
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"kernel", probe->lsp_func, probe->lsp_name,
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probe->lsp_frame, probe);
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#else
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probe->lsp_id = dtrace_probe_create(lockstat_id,
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__UNCONST("kernel"), __UNCONST(probe->lsp_func),
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__UNCONST(probe->lsp_name), LOCKSTAT_AFRAMES, probe);
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#endif
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__UNCONST(probe->lsp_name), 1, probe);
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}
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}
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@ -327,85 +161,122 @@ static dtrace_pops_t lockstat_pops = {
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};
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static void
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lockstat_load(void *dummy)
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lockstat_barrier_xc(void *arg0 __unused, void *arg1 __unused)
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{
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#ifdef __FreeBSD__
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/* Create the /dev/dtrace/lockstat entry. */
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lockstat_cdev = make_dev(&lockstat_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600,
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"dtrace/lockstat");
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#endif
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if (dtrace_register("lockstat", &lockstat_attr, DTRACE_PRIV_USER,
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NULL, &lockstat_pops, NULL, &lockstat_id) != 0)
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return;
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membar_consumer();
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}
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typedef void (*dtrace_probe_func_t)(dtrace_id_t, uintptr_t, uintptr_t,
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uintptr_t, uintptr_t, uintptr_t);
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static bool
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lockstat_cas_probe(dtrace_probe_func_t old, dtrace_probe_func_t new)
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{
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ASSERT(kernconfig_is_held());
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if (lockstat_probe_func != old)
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return false;
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lockstat_probe_func = new;
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membar_producer();
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xc_wait(xc_broadcast(0, lockstat_barrier_xc, NULL, NULL));
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return true;
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}
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static int
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lockstat_unload(void)
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lockstat_init(void)
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{
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int error = 0;
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int bmaj = -1, cmaj = -1;
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int error;
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bool ok;
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if ((error = dtrace_unregister(lockstat_id)) != 0)
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return (error);
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#ifdef __FreeBSD__
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destroy_dev(lockstat_cdev);
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#endif
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return (error);
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}
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#if defined(__FreeBSD__)
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/* ARGSUSED */
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static int
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lockstat_modevent(module_t mod __unused, int type, void *data __unused)
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{
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int error = 0;
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switch (type) {
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case MOD_LOAD:
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break;
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case MOD_UNLOAD:
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break;
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case MOD_SHUTDOWN:
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break;
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default:
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error = EOPNOTSUPP;
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break;
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/* Install the probe function. */
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ok = lockstat_cas_probe(lockstat_probe_stub, dtrace_probe);
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if (!ok) {
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printf("dtrace_lockstat: lockstat probe already installed\n");
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error = EEXIST;
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goto fail0;
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}
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return (error);
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/* Create a character device. */
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error = devsw_attach("lockstat", NULL, &bmaj, &lockstat_cdevsw, &cmaj);
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if (error) {
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printf("dtrace_lockstat: failed to attach devsw: %d\n", error);
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goto fail1;
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}
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/* Everything is in place. Register a dtrace provider. */
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ASSERT(lockstat_id == 0);
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error = dtrace_register("lockstat", &lockstat_attr, DTRACE_PRIV_USER,
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NULL, &lockstat_pops, NULL, &lockstat_id);
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if (error) {
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printf("dtrace_lockstat: failed to register dtrace provider"
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": %d\n", error);
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goto fail2;
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}
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ASSERT(lockstat_id != 0);
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/* Success! */
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return 0;
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fail2: devsw_detach(NULL, &lockstat_cdevsw);
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fail1: ok = lockstat_cas_probe(dtrace_probe, lockstat_probe_stub);
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ASSERT(ok);
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fail0: ASSERT(error);
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return error;
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}
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SYSINIT(lockstat_load, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, lockstat_load, NULL);
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SYSUNINIT(lockstat_unload, SI_SUB_DTRACE_PROVIDER, SI_ORDER_ANY, lockstat_unload, NULL);
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static int
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lockstat_fini(void)
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{
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int error;
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bool ok __diagused;
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DEV_MODULE(lockstat, lockstat_modevent, NULL);
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MODULE_VERSION(lockstat, 1);
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MODULE_DEPEND(lockstat, dtrace, 1, 1, 1);
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MODULE_DEPEND(lockstat, opensolaris, 1, 1, 1);
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/*
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* If we haven't previously tried to detach and failed,
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||||
* unregister the dtrace provider.
|
||||
*/
|
||||
if (lockstat_id != 0) {
|
||||
error = dtrace_unregister(lockstat_id);
|
||||
if (error) {
|
||||
printf("dtrace_lockstat"
|
||||
": failed to unregister dtrace provider: %d\n",
|
||||
error);
|
||||
return error;
|
||||
}
|
||||
lockstat_id = 0;
|
||||
}
|
||||
|
||||
#elif defined(__NetBSD__)
|
||||
/* Detach the device. */
|
||||
error = devsw_detach(NULL, &lockstat_cdevsw);
|
||||
if (error) {
|
||||
printf("dtrace_lockstat: failed to detach device: %d\n",
|
||||
error);
|
||||
return error;
|
||||
}
|
||||
|
||||
/* Unhook the probe. */
|
||||
ok = lockstat_cas_probe(dtrace_probe, lockstat_probe_stub);
|
||||
ASSERT(ok);
|
||||
|
||||
/* Success! */
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int
|
||||
dtrace_lockstat_modcmd(modcmd_t cmd, void *data)
|
||||
{
|
||||
|
||||
switch (cmd) {
|
||||
case MODULE_CMD_INIT:
|
||||
lockstat_load(NULL);
|
||||
return 0;
|
||||
return lockstat_init();
|
||||
case MODULE_CMD_FINI:
|
||||
return lockstat_unload();
|
||||
case MODULE_CMD_AUTOUNLOAD:
|
||||
return EBUSY;
|
||||
return lockstat_fini();
|
||||
default:
|
||||
return ENOTTY;
|
||||
}
|
||||
}
|
||||
|
||||
MODULE(MODULE_CLASS_MISC, dtrace_lockstat, "dtrace");
|
||||
|
||||
#endif
|
||||
|
|
|
|||
Loading…
Reference in New Issue