PSARC/2009/339 LatencyTOP for OpenSolaris

6825817 Integrate latencyTOP into OpenSolaris
Contributed by Lejun Zhu <lejun.zhu@intel.com>

1 files changed, 573 insertions, 0 deletions

diff --git a/usr/src/cmd/latencytop/common/dwrapper.c b/usr/src/cmd/latencytop/common/dwrapper.c
new file mode 100644
index 0000000000..d1920e5500
--- /dev/null
+++ b/usr/src/cmd/latencytop/common/dwrapper.c
@@ -0,0 +1,573 @@
+/*
+ * 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);
+}