dwrapper.c revision 15db28971f91c98efb449aebf46024ac72779fa3
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2008-2009, Intel Corporation.
* All Rights Reserved.
*/
#include <unistd.h>
#include <stdio.h>
#include <dtrace.h>
#include <string.h>
#include <stdlib.h>
#include <memory.h>
#include <limits.h>
#include "latencytop.h"
static dtrace_hdl_t *g_dtp = NULL; /* dtrace handle */
static pid_t pid_self = -1; /* PID of our own process */
/*
* Ignore sched if sched is not tracked.
* Also ignore ourselves (i.e., latencytop).
*/
#define SHOULD_IGNORE(pid) \
((!g_config.lt_cfg_trace_sched && 0 == (pid)) || pid_self == (pid))
/*
* Get an integer value from dtrace record.
*/
static uint64_t
rec_get_value(void *a, size_t b)
{
uint64_t ret = 0;
switch (b) {
case sizeof (uint64_t):
ret = *((uint64_t *)(a));
break;
case sizeof (uint32_t):
ret = *((uint32_t *)(a));
break;
case sizeof (uint16_t):
ret = *((uint16_t *)(a));
break;
case sizeof (uint8_t):
ret = *((uint8_t *)(a));
break;
default:
break;
}
return (ret);
}
/*
* Callback to process aggregation lt_call_* (related to on/off cpu
* activities) in the snapshot.
*/
static int
aggwalk_call(const dtrace_aggdata_t *data, lt_stat_type_t stat_type)
{
dtrace_aggdesc_t *aggdesc = data->dtada_desc;
dtrace_syminfo_t dts;
GElf_Sym sym;
caddr_t addr;
pid_t pid;
id_t tid;
unsigned int stack_depth;
unsigned int pc_size;
uint64_t pc;
uint64_t agg_value;
char *ptr = NULL;
char *buffer = NULL;
int ptrsize;
unsigned int buffersize;
char *tag = NULL;
unsigned int priority;
enum { REC_PID = 1, REC_TID, REC_STACK, REC_TAG, REC_PRIO, REC_AGG,
NREC };
/* Check action type */
if ((aggdesc->dtagd_nrecs < NREC) ||
(aggdesc->dtagd_rec[REC_PID].dtrd_action != DTRACEACT_DIFEXPR) ||
(aggdesc->dtagd_rec[REC_TID].dtrd_action != DTRACEACT_DIFEXPR) ||
(aggdesc->dtagd_rec[REC_TAG].dtrd_action != DTRACEACT_DIFEXPR) ||
(aggdesc->dtagd_rec[REC_PRIO].dtrd_action != DTRACEACT_DIFEXPR) ||
(!DTRACEACT_ISAGG(aggdesc->dtagd_rec[REC_AGG].dtrd_action)) ||
(aggdesc->dtagd_rec[REC_STACK].dtrd_action != DTRACEACT_STACK)) {
return (-1);
}
pid = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_PID].dtrd_offset,
aggdesc->dtagd_rec[REC_PID].dtrd_size);
if (SHOULD_IGNORE(pid)) {
return (0);
}
tid = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_TID].dtrd_offset,
aggdesc->dtagd_rec[REC_TID].dtrd_size);
/* Parse stack array from dtagd_rec */
stack_depth = aggdesc->dtagd_rec[REC_STACK].dtrd_arg;
pc_size = aggdesc->dtagd_rec[REC_STACK].dtrd_size / stack_depth;
addr = data->dtada_data + aggdesc->dtagd_rec[REC_STACK].dtrd_offset;
buffersize = (stack_depth * (2 * PATH_MAX + 2) + 1) * sizeof (char);
buffer = (char *)lt_malloc(buffersize);
ptr = buffer;
ptrsize = buffersize;
/* Print the stack */
while (stack_depth > 0) {
pc = rec_get_value(addr, pc_size);
if (pc == 0) {
break;
}
addr += pc_size;
if (dtrace_lookup_by_addr(g_dtp, pc, &sym, &dts) == 0) {
int len;
len = snprintf(ptr, ptrsize,
"%s`%s ", dts.dts_object, dts.dts_name);
ptrsize -= len;
if (ptrsize <= 0) {
/*
* snprintf returns "desired" length, so
* reaching here means our buffer is full.
* Move ptr to the last byte of the buffer and
* break.
*/
ptr = &buffer[buffersize-1];
break;
} else {
ptr += len;
}
}
}
if (ptr != buffer) {
/*
* We have printed something, so it is safe to remove
* the last ' '.
*/
*(ptr-1) = '\0';
}
tag = (char *)data->dtada_data +
aggdesc->dtagd_rec[REC_TAG].dtrd_offset;
priority = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_PRIO].dtrd_offset,
aggdesc->dtagd_rec[REC_PRIO].dtrd_size);
agg_value = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_AGG].dtrd_offset,
aggdesc->dtagd_rec[REC_AGG].dtrd_size);
lt_stat_update(pid, tid, buffer, tag, priority, stat_type, agg_value);
if (buffer != NULL) {
free(buffer);
}
return (0);
}
/*
* Callback to process aggregation lt_named_* (related to lock spinning etc.),
* in the snapshot.
*/
static int
aggwalk_named(const dtrace_aggdata_t *data, lt_stat_type_t stat_type)
{
dtrace_aggdesc_t *aggdesc = data->dtada_desc;
pid_t pid;
id_t tid;
uint64_t agg_value;
int cause_id;
char *type = NULL;
enum { REC_PID = 1, REC_TID, REC_TYPE, REC_AGG, NREC };
/* Check action type */
if ((aggdesc->dtagd_nrecs < NREC) ||
(aggdesc->dtagd_rec[REC_PID].dtrd_action != DTRACEACT_DIFEXPR) ||
(aggdesc->dtagd_rec[REC_TID].dtrd_action != DTRACEACT_DIFEXPR) ||
(aggdesc->dtagd_rec[REC_TYPE].dtrd_action != DTRACEACT_DIFEXPR) ||
(!DTRACEACT_ISAGG(aggdesc->dtagd_rec[REC_AGG].dtrd_action))) {
return (-1);
}
pid = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_PID].dtrd_offset,
aggdesc->dtagd_rec[REC_PID].dtrd_size);
if (SHOULD_IGNORE(pid)) {
return (0);
}
tid = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_TID].dtrd_offset,
aggdesc->dtagd_rec[REC_TID].dtrd_size);
type = (char *)data->dtada_data
+ aggdesc->dtagd_rec[REC_TYPE].dtrd_offset;
cause_id = lt_table_cause_from_name(type, 1, CAUSE_FLAG_SPECIAL);
agg_value = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_AGG].dtrd_offset,
aggdesc->dtagd_rec[REC_AGG].dtrd_size);
lt_stat_update_cause(pid, tid, cause_id, stat_type, agg_value);
return (0);
}
/*
* Callback to process aggregation lt_sync_* (related to synchronization
* objects), in the snapshot.
*/
static int
aggwalk_sync(const dtrace_aggdata_t *data, lt_stat_type_t stat_type)
{
dtrace_aggdesc_t *aggdesc = data->dtada_desc;
pid_t pid;
id_t tid;
uint64_t agg_value;
int stype;
unsigned long long wchan;
enum { REC_PID = 1, REC_TID, REC_STYPE, REC_WCHAN, REC_AGG, NREC };
/* Check action type */
if ((aggdesc->dtagd_nrecs < NREC) ||
(aggdesc->dtagd_rec[REC_PID].dtrd_action != DTRACEACT_DIFEXPR) ||
(aggdesc->dtagd_rec[REC_TID].dtrd_action != DTRACEACT_DIFEXPR) ||
(aggdesc->dtagd_rec[REC_STYPE].dtrd_action != DTRACEACT_DIFEXPR) ||
(aggdesc->dtagd_rec[REC_WCHAN].dtrd_action != DTRACEACT_DIFEXPR) ||
(!DTRACEACT_ISAGG(aggdesc->dtagd_rec[REC_AGG].dtrd_action))) {
return (-1);
}
pid = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_PID].dtrd_offset,
aggdesc->dtagd_rec[REC_PID].dtrd_size);
if (SHOULD_IGNORE(pid)) {
return (0);
}
tid = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_TID].dtrd_offset,
aggdesc->dtagd_rec[REC_TID].dtrd_size);
stype = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_STYPE].dtrd_offset,
aggdesc->dtagd_rec[REC_STYPE].dtrd_size);
wchan = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_WCHAN].dtrd_offset,
aggdesc->dtagd_rec[REC_WCHAN].dtrd_size);
agg_value = rec_get_value(
data->dtada_data + aggdesc->dtagd_rec[REC_AGG].dtrd_offset,
aggdesc->dtagd_rec[REC_AGG].dtrd_size);
lt_stat_update_sobj(pid, tid, stype, wchan, stat_type, agg_value);
return (0);
}
/*
* Callback to process various aggregations in the snapshot. Called by
* different aggwalk_* functions.
*/
/* ARGSUSED */
static int
aggwalk(const dtrace_aggdata_t *data, void *arg)
{
char *tmp;
char buffer[32];
lt_stat_type_t stat_type;
int (*func)(const dtrace_aggdata_t *, lt_stat_type_t);
(void) strncpy(buffer, data->dtada_desc->dtagd_name, sizeof (buffer));
buffer[sizeof (buffer) - 1] = '\0';
tmp = strtok(buffer, "_");
if (tmp == NULL || strcmp(tmp, "lt") != 0) {
goto done;
}
tmp = strtok(NULL, "_");
if (tmp == NULL) {
goto done;
} else if (strcmp(tmp, "call") == 0) {
func = aggwalk_call;
} else if (strcmp(tmp, "named") == 0) {
func = aggwalk_named;
} else if (strcmp(tmp, "sync") == 0) {
func = aggwalk_sync;
} else {
goto done;
}
tmp = strtok(NULL, "_");
if (tmp == NULL) {
goto done;
} else if (strcmp(tmp, "count") == 0) {
stat_type = LT_STAT_COUNT;
} else if (strcmp(tmp, "sum") == 0) {
stat_type = LT_STAT_SUM;
} else if (strcmp(tmp, "max") == 0) {
stat_type = LT_STAT_MAX;
} else {
goto done;
}
(void) func(data, stat_type);
done:
/* We have our data, so remove it from DTrace now */
return (DTRACE_AGGWALK_REMOVE);
}
/*
* Callback to handle event caused by DTrace dropping data.
*/
/*ARGSUSED*/
static int
drop_handler(const dtrace_dropdata_t *data, void *user)
{
lt_display_error("Drop: %s\n", data->dtdda_msg);
/* Pretend nothing happened, so just continue */
return (DTRACE_HANDLE_OK);
}
#ifndef EMBED_CONFIGS
/*
* Copy the content from a "real" file into a temp file.
*/
static int
copy_tmp_file(const char *src, FILE *dst)
{
FILE *tmp = NULL;
char buffer[256];
int bytes;
if ((tmp = fopen(src, "r")) == NULL) {
return (-1);
}
while ((bytes = fread(buffer, 1, sizeof (buffer), tmp)) > 0) {
if (fwrite(buffer, bytes, 1, dst) != 1) {
return (-1);
}
}
(void) fclose(tmp);
return (0);
}
#endif
/*
* DTrace initialization. D script starts running when this function returns.
*/
int
lt_dtrace_init(void)
{
dtrace_prog_t *prog;
dtrace_proginfo_t info;
int err;
FILE *fp_script = NULL;
pid_self = getpid();
if ((g_dtp = dtrace_open(DTRACE_VERSION, 0, &err)) == NULL) {
lt_display_error("Cannot open dtrace library: %s\n",
dtrace_errmsg(NULL, err));
return (-1);
}
if (dtrace_handle_drop(g_dtp, &drop_handler, NULL) == -1) {
lt_display_error("Cannot install DTrace handle: %s\n",
dtrace_errmsg(NULL, err));
return (-1);
}
if (g_config.lt_cfg_enable_filter) {
if ((err = dtrace_setopt(g_dtp, "define",
"ENABLE_FILTER")) != 0) {
lt_display_error(
"Failed to set option ENABLE_FILTER.\n");
return (err);
}
}
if (g_config.lt_cfg_trace_syncobj) {
if ((err = dtrace_setopt(g_dtp, "define",
"ENABLE_SYNCOBJ")) != 0) {
lt_display_error(
"Failed to set option ENABLE_SYNCOBJ.\n");
return (err);
}
}
if (g_config.lt_cfg_trace_sched) {
if ((err = dtrace_setopt(g_dtp, "define",
"ENABLE_SCHED")) != 0) {
lt_display_error(
"Failed to set option ENABLE_SYNCOBJ.\n");
return (err);
}
}
if (g_config.lt_cfg_low_overhead_mode) {
if ((err = dtrace_setopt(g_dtp, "define",
"ENABLE_LOW_OVERHEAD")) != 0) {
lt_display_error(
"Failed to set option ENABLE_SYNCOBJ.\n");
return (err);
}
}
/* Create a temp file; libdtrace needs it for cpp(1) */
if ((fp_script = tmpfile()) == NULL) {
lt_display_error("Cannot create tmp file\n");
return (-1);
}
/* Copy the main D script into the temp file */
#ifdef EMBED_CONFIGS
if (fwrite(&latencytop_d_start,
(size_t)(&latencytop_d_end - &latencytop_d_start), 1, fp_script)
!= 1) {
lt_display_error("Could not copy D script, fwrite() failed\n");
(void) fclose(fp_script);
return (-1);
}
#else
if (copy_tmp_file(DEFAULT_D_SCRIPT_NAME, fp_script) != 0) {
lt_display_error("Cannot open script file %s\n",
DEFAULT_D_SCRIPT_NAME);
(void) fclose(fp_script);
return (-1);
}
#endif /* EMBED_CONFIGS */
if (lt_table_append_trans(fp_script) != 0) {
(void) fclose(fp_script);
return (-1);
}
(void) fseek(fp_script, 0, SEEK_SET);
if ((prog = dtrace_program_fcompile(g_dtp, fp_script,
DTRACE_C_CPP, 0, NULL)) == NULL) {
lt_display_error("Failed to compile D script.\n");
(void) fclose(fp_script);
return (dtrace_errno(g_dtp));
}
(void) fclose(fp_script);
/* Execute the D script */
if (dtrace_program_exec(g_dtp, prog, &info) == -1) {
lt_display_error("Failed to enable probes.\n");
return (dtrace_errno(g_dtp));
}
if (dtrace_go(g_dtp) != 0) {
lt_display_error("Failed to run D script.\n");
return (dtrace_errno(g_dtp));
}
return (0);
}
/*
* Worker function to move aggregate data to user space. Called periodically
* to prevent the kernel from running out of memory.
*/
int
lt_dtrace_work(int force)
{
static uint64_t last_snap = 0;
uint64_t now = lt_millisecond();
if (!force && now - last_snap < g_config.lt_cfg_snap_interval) {
return (last_snap + g_config.lt_cfg_snap_interval - now);
}
if (dtrace_status(g_dtp) == -1) {
lt_display_error("Failed when getting status: %s\n",
dtrace_errmsg(g_dtp, dtrace_errno(g_dtp)));
return (-1);
}
if (dtrace_aggregate_snap(g_dtp) != 0) {
lt_display_error("Failed to snap aggregate: %s\n",
dtrace_errmsg(g_dtp, dtrace_errno(g_dtp)));
return (-1);
}
last_snap = now;
return (0);
}
/*
* Walk through dtrace aggregator and collect data for latencytop to display.
* Called immediately before UI update.
*/
int
lt_dtrace_collect(void)
{
if (lt_dtrace_work(1) != 0) {
return (-1);
}
if (dtrace_aggregate_walk(g_dtp, aggwalk, NULL) != 0) {
lt_display_error("Failed to sort aggregate: %s\n",
dtrace_errmsg(g_dtp, dtrace_errno(g_dtp)));
return (-1);
}
/*
* Probably we don't need to clear again, because we have removed
* everything. Paranoid ?
*/
dtrace_aggregate_clear(g_dtp);
return (0);
}
/*
* dtrace clean up.
*/
void
lt_dtrace_deinit(void)
{
(void) dtrace_stop(g_dtp);
dtrace_close(g_dtp);
}