dev/hwpmc/hwpmc_logging.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>
__MBSDID("$MidnightBSD$");

#include <sys/param.h>
#include <sys/capability.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_EMITNULLSTRING(L) do { bzero(_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 proc *p;
        struct ucred *ownercred;
        struct ucred *mycred;
        struct thread *td;
        struct uio auio;
        struct iovec aiov;
        size_t nbytes;

        po = (struct pmc_owner *) arg;
        p = po->po_owner;
        td = curthread;
        mycred = td->td_ucred;

        PROC_LOCK(p);
        ownercred = crhold(p->p_ucred);
        PROC_UNLOCK(p);

        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);

                                /* No more buffers and shutdown required. */
                                if (po->po_flags & PMC_PO_SHUTDOWN) {
                                        mtx_unlock(&pmc_kthread_mtx);
                                        /*
                                         * Close the file to get PMCLOG_EOF
                                         * error in pmclog(3).
                                         */
                                        fo_close(po->po_file, curthread);
                                        mtx_lock(&pmc_kthread_mtx);
                                        break;
                                }

                                (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;

                if (error) {
                        /* XXX some errors are recoverable */
                        /* send a SIGIO to the owner and exit */
                        PROC_LOCK(p);
                        kern_psignal(p, SIGIO);
                        PROC_UNLOCK(p);

                        mtx_lock(&pmc_kthread_mtx);

                        po->po_error = error; /* save for flush log */

                        PMCDBG(LOG,WRI,2, "po=%p error=%d", po, error);

                        break;
                }

                mtx_lock(&pmc_kthread_mtx);

                /* 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;
        }

        wakeup_one(po->po_kthread);
        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);

        /* No more data when shutdown in progress. */
        if (po->po_flags & PMC_PO_SHUTDOWN) {
                mtx_unlock_spin(&po->po_mtx);
                return (NULL);
        }

        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)
{
        /*
         * Close the file to force the thread out of fo_write,
         * unset flag, wakeup the helper thread,
         * wait for it to exit
         */

        if (po->po_file != NULL)
                fo_close(po->po_file, curthread);

        mtx_lock(&pmc_kthread_mtx);
        po->po_flags &= ~PMC_PO_OWNS_LOGFILE;
        wakeup_one(po);
        if (po->po_kthread)
                msleep(po->po_kthread, &pmc_kthread_mtx, PPAUSE, "pmckstp", 0);
        mtx_unlock(&pmc_kthread_mtx);
}

/*
 * 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, CAP_WRITE, &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 */
        if (po->po_kthread)
                pmclog_stop_kthread(po);

        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 */
        pmclog_stop_kthread(po);

        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;
        struct pmclog_buffer *lb;

        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 and not empty.
         */
        mtx_lock_spin(&po->po_mtx);
        lb = po->po_curbuf;
        if (lb && lb->plb_ptr != lb->plb_base) {
                pmclog_schedule_io(po);
        } else
                error = ENOBUFS;
        mtx_unlock_spin(&po->po_mtx);

 error:
        mtx_unlock(&pmc_kthread_mtx);

        return (error);
}

int
pmclog_close(struct pmc_owner *po)
{

        PMCDBG(LOG,CLO,1, "po=%p", po);

        mtx_lock(&pmc_kthread_mtx);

        /*
         * Schedule the current buffer.
         */
        mtx_lock_spin(&po->po_mtx);
        if (po->po_curbuf)
                pmclog_schedule_io(po);
        else
                wakeup_one(po);
        mtx_unlock_spin(&po->po_mtx);

        /*
         * Initiate shutdown: no new data queued,
         * thread will close file on last block.
         */
        po->po_flags |= PMC_PO_SHUTDOWN;

        mtx_unlock(&pmc_kthread_mtx);

        return (0);
}

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;
        struct pmc_soft *ps;

        po = pm->pm_owner;

        PMCDBG(LOG,ALL,1, "pm=%p", pm);

        if (PMC_TO_CLASS(pm) == PMC_CLASS_SOFT) {
                PMCLOG_RESERVE(po, PMCALLOCATEDYN,
                    sizeof(struct pmclog_pmcallocatedyn));
                PMCLOG_EMIT32(pm->pm_id);
                PMCLOG_EMIT32(pm->pm_event);
                PMCLOG_EMIT32(pm->pm_flags);
                ps = pmc_soft_ev_acquire(pm->pm_event);
                if (ps != NULL)
                        PMCLOG_EMITSTRING(ps->ps_ev.pm_ev_name,PMC_NAME_MAX);
                else
                        PMCLOG_EMITNULLSTRING(PMC_NAME_MAX);
                pmc_soft_ev_release(ps);
                PMCLOG_DESPATCH(po);
        } else {
                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);
        }
}
Revision:	5612
Committed:	Sat Jan 5 19:17:48 2013 UTC (11 years, 4 months ago) by laffer1
Content type:	text/plain
File size:	26761 byte(s)
Log Message:	sync and tag