freebsd-dev/sys/dev/hwpmc/hwpmc_logging.c
Attilio Rao ca2d94bef7 Fix a LOR between pmc_sx and proctree/allproc when creating a new thread
for the pmclog.

Reported by:	Ryan Stone <rstone at sandvine dot com>
Tested by:	Ryan Stone <rstone at sandvine dot com>
Sponsored by:	Sandvine Incorporated
2009-06-25 20:59:37 +00:00

1018 lines
25 KiB
C

/*-
* Copyright (c) 2005-2007 Joseph Koshy
* Copyright (c) 2007 The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed by A. Joseph Koshy under
* sponsorship from the FreeBSD Foundation and Google, Inc.
*
* 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.
*
*/
/*
* Logging code for hwpmc(4)
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/file.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/pmc.h>
#include <sys/pmckern.h>
#include <sys/pmclog.h>
#include <sys/proc.h>
#include <sys/signalvar.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
/*
* Sysctl tunables
*/
SYSCTL_DECL(_kern_hwpmc);
/*
* kern.hwpmc.logbuffersize -- size of the per-cpu owner buffers.
*/
static int pmclog_buffer_size = PMC_LOG_BUFFER_SIZE;
TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "logbuffersize", &pmclog_buffer_size);
SYSCTL_INT(_kern_hwpmc, OID_AUTO, logbuffersize, CTLFLAG_TUN|CTLFLAG_RD,
&pmclog_buffer_size, 0, "size of log buffers in kilobytes");
/*
* kern.hwpmc.nbuffer -- number of global log buffers
*/
static int pmc_nlogbuffers = PMC_NLOGBUFFERS;
TUNABLE_INT(PMC_SYSCTL_NAME_PREFIX "nbuffers", &pmc_nlogbuffers);
SYSCTL_INT(_kern_hwpmc, OID_AUTO, nbuffers, CTLFLAG_TUN|CTLFLAG_RD,
&pmc_nlogbuffers, 0, "number of global log buffers");
/*
* Global log buffer list and associated spin lock.
*/
TAILQ_HEAD(, pmclog_buffer) pmc_bufferlist =
TAILQ_HEAD_INITIALIZER(pmc_bufferlist);
static struct mtx pmc_bufferlist_mtx; /* spin lock */
static struct mtx pmc_kthread_mtx; /* sleep lock */
#define PMCLOG_INIT_BUFFER_DESCRIPTOR(D) do { \
const int __roundup = roundup(sizeof(*D), \
sizeof(uint32_t)); \
(D)->plb_fence = ((char *) (D)) + \
1024*pmclog_buffer_size; \
(D)->plb_base = (D)->plb_ptr = ((char *) (D)) + \
__roundup; \
} while (0)
/*
* Log file record constructors.
*/
#define _PMCLOG_TO_HEADER(T,L) \
((PMCLOG_HEADER_MAGIC << 24) | \
(PMCLOG_TYPE_ ## T << 16) | \
((L) & 0xFFFF))
/* reserve LEN bytes of space and initialize the entry header */
#define _PMCLOG_RESERVE(PO,TYPE,LEN,ACTION) do { \
uint32_t *_le; \
int _len = roundup((LEN), sizeof(uint32_t)); \
if ((_le = pmclog_reserve((PO), _len)) == NULL) { \
ACTION; \
} \
*_le = _PMCLOG_TO_HEADER(TYPE,_len); \
_le += 3 /* skip over timestamp */
#define PMCLOG_RESERVE(P,T,L) _PMCLOG_RESERVE(P,T,L,return)
#define PMCLOG_RESERVE_WITH_ERROR(P,T,L) _PMCLOG_RESERVE(P,T,L, \
error=ENOMEM;goto error)
#define PMCLOG_EMIT32(V) do { *_le++ = (V); } while (0)
#define PMCLOG_EMIT64(V) do { \
*_le++ = (uint32_t) ((V) & 0xFFFFFFFF); \
*_le++ = (uint32_t) (((V) >> 32) & 0xFFFFFFFF); \
} while (0)
/* Emit a string. Caution: does NOT update _le, so needs to be last */
#define PMCLOG_EMITSTRING(S,L) do { bcopy((S), _le, (L)); } while (0)
#define PMCLOG_DESPATCH(PO) \
pmclog_release((PO)); \
} while (0)
/*
* Assertions about the log file format.
*/
CTASSERT(sizeof(struct pmclog_callchain) == 6*4 +
PMC_CALLCHAIN_DEPTH_MAX*sizeof(uintfptr_t));
CTASSERT(sizeof(struct pmclog_closelog) == 3*4);
CTASSERT(sizeof(struct pmclog_dropnotify) == 3*4);
CTASSERT(sizeof(struct pmclog_map_in) == PATH_MAX +
4*4 + sizeof(uintfptr_t));
CTASSERT(offsetof(struct pmclog_map_in,pl_pathname) ==
4*4 + sizeof(uintfptr_t));
CTASSERT(sizeof(struct pmclog_map_out) == 4*4 + 2*sizeof(uintfptr_t));
CTASSERT(sizeof(struct pmclog_pcsample) == 6*4 + sizeof(uintfptr_t));
CTASSERT(sizeof(struct pmclog_pmcallocate) == 6*4);
CTASSERT(sizeof(struct pmclog_pmcattach) == 5*4 + PATH_MAX);
CTASSERT(offsetof(struct pmclog_pmcattach,pl_pathname) == 5*4);
CTASSERT(sizeof(struct pmclog_pmcdetach) == 5*4);
CTASSERT(sizeof(struct pmclog_proccsw) == 5*4 + 8);
CTASSERT(sizeof(struct pmclog_procexec) == 5*4 + PATH_MAX +
sizeof(uintfptr_t));
CTASSERT(offsetof(struct pmclog_procexec,pl_pathname) == 5*4 +
sizeof(uintfptr_t));
CTASSERT(sizeof(struct pmclog_procexit) == 5*4 + 8);
CTASSERT(sizeof(struct pmclog_procfork) == 5*4);
CTASSERT(sizeof(struct pmclog_sysexit) == 4*4);
CTASSERT(sizeof(struct pmclog_userdata) == 4*4);
/*
* Log buffer structure
*/
struct pmclog_buffer {
TAILQ_ENTRY(pmclog_buffer) plb_next;
char *plb_base;
char *plb_ptr;
char *plb_fence;
};
/*
* Prototypes
*/
static int pmclog_get_buffer(struct pmc_owner *po);
static void pmclog_loop(void *arg);
static void pmclog_release(struct pmc_owner *po);
static uint32_t *pmclog_reserve(struct pmc_owner *po, int length);
static void pmclog_schedule_io(struct pmc_owner *po);
static void pmclog_stop_kthread(struct pmc_owner *po);
/*
* Helper functions
*/
/*
* Get a log buffer
*/
static int
pmclog_get_buffer(struct pmc_owner *po)
{
struct pmclog_buffer *plb;
mtx_assert(&po->po_mtx, MA_OWNED);
KASSERT(po->po_curbuf == NULL,
("[pmclog,%d] po=%p current buffer still valid", __LINE__, po));
mtx_lock_spin(&pmc_bufferlist_mtx);
if ((plb = TAILQ_FIRST(&pmc_bufferlist)) != NULL)
TAILQ_REMOVE(&pmc_bufferlist, plb, plb_next);
mtx_unlock_spin(&pmc_bufferlist_mtx);
PMCDBG(LOG,GTB,1, "po=%p plb=%p", po, plb);
#ifdef DEBUG
if (plb)
KASSERT(plb->plb_ptr == plb->plb_base &&
plb->plb_base < plb->plb_fence,
("[pmclog,%d] po=%p buffer invariants: ptr=%p "
"base=%p fence=%p", __LINE__, po, plb->plb_ptr,
plb->plb_base, plb->plb_fence));
#endif
po->po_curbuf = plb;
/* update stats */
atomic_add_int(&pmc_stats.pm_buffer_requests, 1);
if (plb == NULL)
atomic_add_int(&pmc_stats.pm_buffer_requests_failed, 1);
return (plb ? 0 : ENOMEM);
}
/*
* Log handler loop.
*
* This function is executed by each pmc owner's helper thread.
*/
static void
pmclog_loop(void *arg)
{
int error;
struct pmc_owner *po;
struct pmclog_buffer *lb;
struct ucred *ownercred;
struct ucred *mycred;
struct thread *td;
struct uio auio;
struct iovec aiov;
size_t nbytes;
po = (struct pmc_owner *) arg;
td = curthread;
mycred = td->td_ucred;
PROC_LOCK(po->po_owner);
ownercred = crhold(po->po_owner->p_ucred);
PROC_UNLOCK(po->po_owner);
PMCDBG(LOG,INI,1, "po=%p kt=%p", po, po->po_kthread);
KASSERT(po->po_kthread == curthread->td_proc,
("[pmclog,%d] proc mismatch po=%p po/kt=%p curproc=%p", __LINE__,
po, po->po_kthread, curthread->td_proc));
lb = NULL;
/*
* Loop waiting for I/O requests to be added to the owner
* struct's queue. The loop is exited when the log file
* is deconfigured.
*/
mtx_lock(&pmc_kthread_mtx);
for (;;) {
/* check if we've been asked to exit */
if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)
break;
if (lb == NULL) { /* look for a fresh buffer to write */
mtx_lock_spin(&po->po_mtx);
if ((lb = TAILQ_FIRST(&po->po_logbuffers)) == NULL) {
mtx_unlock_spin(&po->po_mtx);
/*
* Wakeup the thread waiting for the
* PMC_OP_FLUSHLOG request to
* complete.
*/
if (po->po_flags & PMC_PO_IN_FLUSH) {
po->po_flags &= ~PMC_PO_IN_FLUSH;
wakeup_one(po->po_kthread);
}
(void) msleep(po, &pmc_kthread_mtx, PWAIT,
"pmcloop", 0);
continue;
}
TAILQ_REMOVE(&po->po_logbuffers, lb, plb_next);
mtx_unlock_spin(&po->po_mtx);
}
mtx_unlock(&pmc_kthread_mtx);
/* process the request */
PMCDBG(LOG,WRI,2, "po=%p base=%p ptr=%p", po,
lb->plb_base, lb->plb_ptr);
/* change our thread's credentials before issuing the I/O */
aiov.iov_base = lb->plb_base;
aiov.iov_len = nbytes = lb->plb_ptr - lb->plb_base;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = -1;
auio.uio_resid = nbytes;
auio.uio_rw = UIO_WRITE;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_td = td;
/* switch thread credentials -- see kern_ktrace.c */
td->td_ucred = ownercred;
error = fo_write(po->po_file, &auio, ownercred, 0, td);
td->td_ucred = mycred;
mtx_lock(&pmc_kthread_mtx);
if (error) {
/* XXX some errors are recoverable */
/* XXX also check for SIGPIPE if a socket */
/* send a SIGIO to the owner and exit */
PROC_LOCK(po->po_owner);
psignal(po->po_owner, SIGIO);
PROC_UNLOCK(po->po_owner);
po->po_error = error; /* save for flush log */
PMCDBG(LOG,WRI,2, "po=%p error=%d", po, error);
break;
}
/* put the used buffer back into the global pool */
PMCLOG_INIT_BUFFER_DESCRIPTOR(lb);
mtx_lock_spin(&pmc_bufferlist_mtx);
TAILQ_INSERT_HEAD(&pmc_bufferlist, lb, plb_next);
mtx_unlock_spin(&pmc_bufferlist_mtx);
lb = NULL;
}
po->po_kthread = NULL;
mtx_unlock(&pmc_kthread_mtx);
/* return the current I/O buffer to the global pool */
if (lb) {
PMCLOG_INIT_BUFFER_DESCRIPTOR(lb);
mtx_lock_spin(&pmc_bufferlist_mtx);
TAILQ_INSERT_HEAD(&pmc_bufferlist, lb, plb_next);
mtx_unlock_spin(&pmc_bufferlist_mtx);
}
/*
* Exit this thread, signalling the waiter
*/
crfree(ownercred);
kproc_exit(0);
}
/*
* Release and log entry and schedule an I/O if needed.
*/
static void
pmclog_release(struct pmc_owner *po)
{
KASSERT(po->po_curbuf->plb_ptr >= po->po_curbuf->plb_base,
("[pmclog,%d] buffer invariants po=%p ptr=%p base=%p", __LINE__,
po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_base));
KASSERT(po->po_curbuf->plb_ptr <= po->po_curbuf->plb_fence,
("[pmclog,%d] buffer invariants po=%p ptr=%p fenc=%p", __LINE__,
po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_fence));
/* schedule an I/O if we've filled a buffer */
if (po->po_curbuf->plb_ptr >= po->po_curbuf->plb_fence)
pmclog_schedule_io(po);
mtx_unlock_spin(&po->po_mtx);
PMCDBG(LOG,REL,1, "po=%p", po);
}
/*
* Attempt to reserve 'length' bytes of space in an owner's log
* buffer. The function returns a pointer to 'length' bytes of space
* if there was enough space or returns NULL if no space was
* available. Non-null returns do so with the po mutex locked. The
* caller must invoke pmclog_release() on the pmc owner structure
* when done.
*/
static uint32_t *
pmclog_reserve(struct pmc_owner *po, int length)
{
uintptr_t newptr, oldptr;
uint32_t *lh;
struct timespec ts;
PMCDBG(LOG,ALL,1, "po=%p len=%d", po, length);
KASSERT(length % sizeof(uint32_t) == 0,
("[pmclog,%d] length not a multiple of word size", __LINE__));
mtx_lock_spin(&po->po_mtx);
if (po->po_curbuf == NULL)
if (pmclog_get_buffer(po) != 0) {
mtx_unlock_spin(&po->po_mtx);
return (NULL);
}
KASSERT(po->po_curbuf != NULL,
("[pmclog,%d] po=%p no current buffer", __LINE__, po));
KASSERT(po->po_curbuf->plb_ptr >= po->po_curbuf->plb_base &&
po->po_curbuf->plb_ptr <= po->po_curbuf->plb_fence,
("[pmclog,%d] po=%p buffer invariants: ptr=%p base=%p fence=%p",
__LINE__, po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_base,
po->po_curbuf->plb_fence));
oldptr = (uintptr_t) po->po_curbuf->plb_ptr;
newptr = oldptr + length;
KASSERT(oldptr != (uintptr_t) NULL,
("[pmclog,%d] po=%p Null log buffer pointer", __LINE__, po));
/*
* If we have space in the current buffer, return a pointer to
* available space with the PO structure locked.
*/
if (newptr <= (uintptr_t) po->po_curbuf->plb_fence) {
po->po_curbuf->plb_ptr = (char *) newptr;
goto done;
}
/*
* Otherwise, schedule the current buffer for output and get a
* fresh buffer.
*/
pmclog_schedule_io(po);
if (pmclog_get_buffer(po) != 0) {
mtx_unlock_spin(&po->po_mtx);
return (NULL);
}
KASSERT(po->po_curbuf != NULL,
("[pmclog,%d] po=%p no current buffer", __LINE__, po));
KASSERT(po->po_curbuf->plb_ptr != NULL,
("[pmclog,%d] null return from pmc_get_log_buffer", __LINE__));
KASSERT(po->po_curbuf->plb_ptr == po->po_curbuf->plb_base &&
po->po_curbuf->plb_ptr <= po->po_curbuf->plb_fence,
("[pmclog,%d] po=%p buffer invariants: ptr=%p base=%p fence=%p",
__LINE__, po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_base,
po->po_curbuf->plb_fence));
oldptr = (uintptr_t) po->po_curbuf->plb_ptr;
done:
lh = (uint32_t *) oldptr;
lh++; /* skip header */
getnanotime(&ts); /* fill in the timestamp */
*lh++ = ts.tv_sec & 0xFFFFFFFF;
*lh++ = ts.tv_nsec & 0xFFFFFFF;
return ((uint32_t *) oldptr);
}
/*
* Schedule an I/O.
*
* Transfer the current buffer to the helper kthread.
*/
static void
pmclog_schedule_io(struct pmc_owner *po)
{
KASSERT(po->po_curbuf != NULL,
("[pmclog,%d] schedule_io with null buffer po=%p", __LINE__, po));
KASSERT(po->po_curbuf->plb_ptr >= po->po_curbuf->plb_base,
("[pmclog,%d] buffer invariants po=%p ptr=%p base=%p", __LINE__,
po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_base));
KASSERT(po->po_curbuf->plb_ptr <= po->po_curbuf->plb_fence,
("[pmclog,%d] buffer invariants po=%p ptr=%p fenc=%p", __LINE__,
po, po->po_curbuf->plb_ptr, po->po_curbuf->plb_fence));
PMCDBG(LOG,SIO, 1, "po=%p", po);
mtx_assert(&po->po_mtx, MA_OWNED);
/*
* Add the current buffer to the tail of the buffer list and
* wakeup the helper.
*/
TAILQ_INSERT_TAIL(&po->po_logbuffers, po->po_curbuf, plb_next);
po->po_curbuf = NULL;
wakeup_one(po);
}
/*
* Stop the helper kthread.
*/
static void
pmclog_stop_kthread(struct pmc_owner *po)
{
/*
* Unset flag, wakeup the helper thread,
* wait for it to exit
*/
mtx_assert(&pmc_kthread_mtx, MA_OWNED);
po->po_flags &= ~PMC_PO_OWNS_LOGFILE;
wakeup_one(po);
if (po->po_kthread)
msleep(po->po_kthread, &pmc_kthread_mtx, PPAUSE, "pmckstp", 0);
}
/*
* Public functions
*/
/*
* Configure a log file for pmc owner 'po'.
*
* Parameter 'logfd' is a file handle referencing an open file in the
* owner process. This file needs to have been opened for writing.
*/
int
pmclog_configure_log(struct pmc_mdep *md, struct pmc_owner *po, int logfd)
{
int error;
struct proc *p;
/*
* As long as it is possible to get a LOR between pmc_sx lock and
* proctree/allproc sx locks used for adding a new process, assure
* the former is not held here.
*/
sx_assert(&pmc_sx, SA_UNLOCKED);
PMCDBG(LOG,CFG,1, "config po=%p logfd=%d", po, logfd);
p = po->po_owner;
/* return EBUSY if a log file was already present */
if (po->po_flags & PMC_PO_OWNS_LOGFILE)
return (EBUSY);
KASSERT(po->po_kthread == NULL,
("[pmclog,%d] po=%p kthread (%p) already present", __LINE__, po,
po->po_kthread));
KASSERT(po->po_file == NULL,
("[pmclog,%d] po=%p file (%p) already present", __LINE__, po,
po->po_file));
/* get a reference to the file state */
error = fget_write(curthread, logfd, &po->po_file);
if (error)
goto error;
/* mark process as owning a log file */
po->po_flags |= PMC_PO_OWNS_LOGFILE;
error = kproc_create(pmclog_loop, po, &po->po_kthread,
RFHIGHPID, 0, "hwpmc: proc(%d)", p->p_pid);
if (error)
goto error;
/* mark process as using HWPMCs */
PROC_LOCK(p);
p->p_flag |= P_HWPMC;
PROC_UNLOCK(p);
/* create a log initialization entry */
PMCLOG_RESERVE_WITH_ERROR(po, INITIALIZE,
sizeof(struct pmclog_initialize));
PMCLOG_EMIT32(PMC_VERSION);
PMCLOG_EMIT32(md->pmd_cputype);
PMCLOG_DESPATCH(po);
return (0);
error:
/* shutdown the thread */
mtx_lock(&pmc_kthread_mtx);
if (po->po_kthread)
pmclog_stop_kthread(po);
mtx_unlock(&pmc_kthread_mtx);
KASSERT(po->po_kthread == NULL, ("[pmclog,%d] po=%p kthread not "
"stopped", __LINE__, po));
if (po->po_file)
(void) fdrop(po->po_file, curthread);
po->po_file = NULL; /* clear file and error state */
po->po_error = 0;
return (error);
}
/*
* De-configure a log file. This will throw away any buffers queued
* for this owner process.
*/
int
pmclog_deconfigure_log(struct pmc_owner *po)
{
int error;
struct pmclog_buffer *lb;
PMCDBG(LOG,CFG,1, "de-config po=%p", po);
if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0)
return (EINVAL);
KASSERT(po->po_sscount == 0,
("[pmclog,%d] po=%p still owning SS PMCs", __LINE__, po));
KASSERT(po->po_file != NULL,
("[pmclog,%d] po=%p no log file", __LINE__, po));
/* stop the kthread, this will reset the 'OWNS_LOGFILE' flag */
mtx_lock(&pmc_kthread_mtx);
if (po->po_kthread)
pmclog_stop_kthread(po);
mtx_unlock(&pmc_kthread_mtx);
KASSERT(po->po_kthread == NULL,
("[pmclog,%d] po=%p kthread not stopped", __LINE__, po));
/* return all queued log buffers to the global pool */
while ((lb = TAILQ_FIRST(&po->po_logbuffers)) != NULL) {
TAILQ_REMOVE(&po->po_logbuffers, lb, plb_next);
PMCLOG_INIT_BUFFER_DESCRIPTOR(lb);
mtx_lock_spin(&pmc_bufferlist_mtx);
TAILQ_INSERT_HEAD(&pmc_bufferlist, lb, plb_next);
mtx_unlock_spin(&pmc_bufferlist_mtx);
}
/* return the 'current' buffer to the global pool */
if ((lb = po->po_curbuf) != NULL) {
PMCLOG_INIT_BUFFER_DESCRIPTOR(lb);
mtx_lock_spin(&pmc_bufferlist_mtx);
TAILQ_INSERT_HEAD(&pmc_bufferlist, lb, plb_next);
mtx_unlock_spin(&pmc_bufferlist_mtx);
}
/* drop a reference to the fd */
error = fdrop(po->po_file, curthread);
po->po_file = NULL;
po->po_error = 0;
return (error);
}
/*
* Flush a process' log buffer.
*/
int
pmclog_flush(struct pmc_owner *po)
{
int error, has_pending_buffers;
PMCDBG(LOG,FLS,1, "po=%p", po);
/*
* If there is a pending error recorded by the logger thread,
* return that.
*/
if (po->po_error)
return (po->po_error);
error = 0;
/*
* Check that we do have an active log file.
*/
mtx_lock(&pmc_kthread_mtx);
if ((po->po_flags & PMC_PO_OWNS_LOGFILE) == 0) {
error = EINVAL;
goto error;
}
/*
* Schedule the current buffer if any.
*/
mtx_lock_spin(&po->po_mtx);
if (po->po_curbuf)
pmclog_schedule_io(po);
has_pending_buffers = !TAILQ_EMPTY(&po->po_logbuffers);
mtx_unlock_spin(&po->po_mtx);
if (has_pending_buffers) {
po->po_flags |= PMC_PO_IN_FLUSH; /* ask for a wakeup */
error = msleep(po->po_kthread, &pmc_kthread_mtx, PWAIT,
"pmcflush", 0);
if (error == 0)
error = po->po_error;
}
error:
mtx_unlock(&pmc_kthread_mtx);
return (error);
}
void
pmclog_process_callchain(struct pmc *pm, struct pmc_sample *ps)
{
int n, recordlen;
uint32_t flags;
struct pmc_owner *po;
PMCDBG(LOG,SAM,1,"pm=%p pid=%d n=%d", pm, ps->ps_pid,
ps->ps_nsamples);
recordlen = offsetof(struct pmclog_callchain, pl_pc) +
ps->ps_nsamples * sizeof(uintfptr_t);
po = pm->pm_owner;
flags = PMC_CALLCHAIN_TO_CPUFLAGS(ps->ps_cpu,ps->ps_flags);
PMCLOG_RESERVE(po, CALLCHAIN, recordlen);
PMCLOG_EMIT32(ps->ps_pid);
PMCLOG_EMIT32(pm->pm_id);
PMCLOG_EMIT32(flags);
for (n = 0; n < ps->ps_nsamples; n++)
PMCLOG_EMITADDR(ps->ps_pc[n]);
PMCLOG_DESPATCH(po);
}
void
pmclog_process_closelog(struct pmc_owner *po)
{
PMCLOG_RESERVE(po,CLOSELOG,sizeof(struct pmclog_closelog));
PMCLOG_DESPATCH(po);
}
void
pmclog_process_dropnotify(struct pmc_owner *po)
{
PMCLOG_RESERVE(po,DROPNOTIFY,sizeof(struct pmclog_dropnotify));
PMCLOG_DESPATCH(po);
}
void
pmclog_process_map_in(struct pmc_owner *po, pid_t pid, uintfptr_t start,
const char *path)
{
int pathlen, recordlen;
KASSERT(path != NULL, ("[pmclog,%d] map-in, null path", __LINE__));
pathlen = strlen(path) + 1; /* #bytes for path name */
recordlen = offsetof(struct pmclog_map_in, pl_pathname) +
pathlen;
PMCLOG_RESERVE(po, MAP_IN, recordlen);
PMCLOG_EMIT32(pid);
PMCLOG_EMITADDR(start);
PMCLOG_EMITSTRING(path,pathlen);
PMCLOG_DESPATCH(po);
}
void
pmclog_process_map_out(struct pmc_owner *po, pid_t pid, uintfptr_t start,
uintfptr_t end)
{
KASSERT(start <= end, ("[pmclog,%d] start > end", __LINE__));
PMCLOG_RESERVE(po, MAP_OUT, sizeof(struct pmclog_map_out));
PMCLOG_EMIT32(pid);
PMCLOG_EMITADDR(start);
PMCLOG_EMITADDR(end);
PMCLOG_DESPATCH(po);
}
void
pmclog_process_pmcallocate(struct pmc *pm)
{
struct pmc_owner *po;
po = pm->pm_owner;
PMCDBG(LOG,ALL,1, "pm=%p", pm);
PMCLOG_RESERVE(po, PMCALLOCATE, sizeof(struct pmclog_pmcallocate));
PMCLOG_EMIT32(pm->pm_id);
PMCLOG_EMIT32(pm->pm_event);
PMCLOG_EMIT32(pm->pm_flags);
PMCLOG_DESPATCH(po);
}
void
pmclog_process_pmcattach(struct pmc *pm, pid_t pid, char *path)
{
int pathlen, recordlen;
struct pmc_owner *po;
PMCDBG(LOG,ATT,1,"pm=%p pid=%d", pm, pid);
po = pm->pm_owner;
pathlen = strlen(path) + 1; /* #bytes for the string */
recordlen = offsetof(struct pmclog_pmcattach, pl_pathname) + pathlen;
PMCLOG_RESERVE(po, PMCATTACH, recordlen);
PMCLOG_EMIT32(pm->pm_id);
PMCLOG_EMIT32(pid);
PMCLOG_EMITSTRING(path, pathlen);
PMCLOG_DESPATCH(po);
}
void
pmclog_process_pmcdetach(struct pmc *pm, pid_t pid)
{
struct pmc_owner *po;
PMCDBG(LOG,ATT,1,"!pm=%p pid=%d", pm, pid);
po = pm->pm_owner;
PMCLOG_RESERVE(po, PMCDETACH, sizeof(struct pmclog_pmcdetach));
PMCLOG_EMIT32(pm->pm_id);
PMCLOG_EMIT32(pid);
PMCLOG_DESPATCH(po);
}
/*
* Log a context switch event to the log file.
*/
void
pmclog_process_proccsw(struct pmc *pm, struct pmc_process *pp, pmc_value_t v)
{
struct pmc_owner *po;
KASSERT(pm->pm_flags & PMC_F_LOG_PROCCSW,
("[pmclog,%d] log-process-csw called gratuitously", __LINE__));
PMCDBG(LOG,SWO,1,"pm=%p pid=%d v=%jx", pm, pp->pp_proc->p_pid,
v);
po = pm->pm_owner;
PMCLOG_RESERVE(po, PROCCSW, sizeof(struct pmclog_proccsw));
PMCLOG_EMIT32(pm->pm_id);
PMCLOG_EMIT64(v);
PMCLOG_EMIT32(pp->pp_proc->p_pid);
PMCLOG_DESPATCH(po);
}
void
pmclog_process_procexec(struct pmc_owner *po, pmc_id_t pmid, pid_t pid,
uintfptr_t startaddr, char *path)
{
int pathlen, recordlen;
PMCDBG(LOG,EXC,1,"po=%p pid=%d path=\"%s\"", po, pid, path);
pathlen = strlen(path) + 1; /* #bytes for the path */
recordlen = offsetof(struct pmclog_procexec, pl_pathname) + pathlen;
PMCLOG_RESERVE(po, PROCEXEC, recordlen);
PMCLOG_EMIT32(pid);
PMCLOG_EMITADDR(startaddr);
PMCLOG_EMIT32(pmid);
PMCLOG_EMITSTRING(path,pathlen);
PMCLOG_DESPATCH(po);
}
/*
* Log a process exit event (and accumulated pmc value) to the log file.
*/
void
pmclog_process_procexit(struct pmc *pm, struct pmc_process *pp)
{
int ri;
struct pmc_owner *po;
ri = PMC_TO_ROWINDEX(pm);
PMCDBG(LOG,EXT,1,"pm=%p pid=%d v=%jx", pm, pp->pp_proc->p_pid,
pp->pp_pmcs[ri].pp_pmcval);
po = pm->pm_owner;
PMCLOG_RESERVE(po, PROCEXIT, sizeof(struct pmclog_procexit));
PMCLOG_EMIT32(pm->pm_id);
PMCLOG_EMIT64(pp->pp_pmcs[ri].pp_pmcval);
PMCLOG_EMIT32(pp->pp_proc->p_pid);
PMCLOG_DESPATCH(po);
}
/*
* Log a fork event.
*/
void
pmclog_process_procfork(struct pmc_owner *po, pid_t oldpid, pid_t newpid)
{
PMCLOG_RESERVE(po, PROCFORK, sizeof(struct pmclog_procfork));
PMCLOG_EMIT32(oldpid);
PMCLOG_EMIT32(newpid);
PMCLOG_DESPATCH(po);
}
/*
* Log a process exit event of the form suitable for system-wide PMCs.
*/
void
pmclog_process_sysexit(struct pmc_owner *po, pid_t pid)
{
PMCLOG_RESERVE(po, SYSEXIT, sizeof(struct pmclog_sysexit));
PMCLOG_EMIT32(pid);
PMCLOG_DESPATCH(po);
}
/*
* Write a user log entry.
*/
int
pmclog_process_userlog(struct pmc_owner *po, struct pmc_op_writelog *wl)
{
int error;
PMCDBG(LOG,WRI,1, "writelog po=%p ud=0x%x", po, wl->pm_userdata);
error = 0;
PMCLOG_RESERVE_WITH_ERROR(po, USERDATA,
sizeof(struct pmclog_userdata));
PMCLOG_EMIT32(wl->pm_userdata);
PMCLOG_DESPATCH(po);
error:
return (error);
}
/*
* Initialization.
*
* Create a pool of log buffers and initialize mutexes.
*/
void
pmclog_initialize()
{
int n;
struct pmclog_buffer *plb;
if (pmclog_buffer_size <= 0) {
(void) printf("hwpmc: tunable logbuffersize=%d must be "
"greater than zero.\n", pmclog_buffer_size);
pmclog_buffer_size = PMC_LOG_BUFFER_SIZE;
}
if (pmc_nlogbuffers <= 0) {
(void) printf("hwpmc: tunable nlogbuffers=%d must be greater "
"than zero.\n", pmc_nlogbuffers);
pmc_nlogbuffers = PMC_NLOGBUFFERS;
}
/* create global pool of log buffers */
for (n = 0; n < pmc_nlogbuffers; n++) {
plb = malloc(1024 * pmclog_buffer_size, M_PMC,
M_WAITOK|M_ZERO);
PMCLOG_INIT_BUFFER_DESCRIPTOR(plb);
TAILQ_INSERT_HEAD(&pmc_bufferlist, plb, plb_next);
}
mtx_init(&pmc_bufferlist_mtx, "pmc-buffer-list", "pmc-leaf",
MTX_SPIN);
mtx_init(&pmc_kthread_mtx, "pmc-kthread", "pmc-sleep", MTX_DEF);
}
/*
* Shutdown logging.
*
* Destroy mutexes and release memory back the to free pool.
*/
void
pmclog_shutdown()
{
struct pmclog_buffer *plb;
mtx_destroy(&pmc_kthread_mtx);
mtx_destroy(&pmc_bufferlist_mtx);
while ((plb = TAILQ_FIRST(&pmc_bufferlist)) != NULL) {
TAILQ_REMOVE(&pmc_bufferlist, plb, plb_next);
free(plb, M_PMC);
}
}