[blktrace.git] / blkiomon.c

/*
 * I/O monitor based on block queue trace data
 *
 * Copyright IBM Corp. 2008
 *
 * Author(s): Martin Peschke <mp3@de.ibm.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <getopt.h>
#include <errno.h>
#include <locale.h>
#include <libgen.h>
#include <sys/msg.h>
#include <pthread.h>
#include <time.h>

#include "blktrace.h"
#include "rbtree.h"
#include "jhash.h"
#include "blkiomon.h"

struct trace {
	struct blk_io_trace bit;
	struct rb_node node;
	struct trace *next;
	long sequence;
};

struct rb_search {
	struct rb_node **node_ptr;
	struct rb_node *parent;
};

struct dstat_msg {
	long mtype;
	struct blkiomon_stat stat;
};

struct dstat {
	struct dstat_msg msg;
	struct rb_node node;
	struct dstat *next;
};

struct output {
	char *fn;
	FILE *fp;
	char *buf;
	int pipe;
};

static char blkiomon_version[] = "0.3";

static FILE *ifp;
static int interval = -1;

static struct trace *vacant_traces_list = NULL;
static int vacant_traces = 0;

#define TRACE_HASH_SIZE 128
struct trace *thash[TRACE_HASH_SIZE] = {};

static struct dstat *vacant_dstats_list = NULL;
static struct rb_root dstat_tree[2] = { RB_ROOT, RB_ROOT };
static struct dstat *dstat_list[2] = {};
static int dstat_curr = 0;

static struct output drvdata, human, binary, debug;

static char *msg_q_name = NULL;
static int msg_q_id = -1, msg_q = -1;
static long msg_id = -1;

static pthread_t interval_thread;
static pthread_mutex_t dstat_mutex = PTHREAD_MUTEX_INITIALIZER;

int data_is_native = -1;

static int up = 1;

/* debugging */
static long leftover = 0, driverdata = 0, match = 0, mismatch = 0, sequence = 0;

static void dump_bit(struct trace *t, const char *descr)
{
	struct blk_io_trace *bit = &t->bit;

	if (!debug.fn)
		return;

	fprintf(debug.fp, "--- %s ---\n", descr);
	fprintf(debug.fp, "magic    %16d\n", bit->magic);
	fprintf(debug.fp, "sequence %16d\n", bit->sequence);
	fprintf(debug.fp, "time     %16ld\n", (unsigned long)bit->time);
	fprintf(debug.fp, "sector   %16ld\n", (unsigned long)bit->sector);
	fprintf(debug.fp, "bytes    %16d\n", bit->bytes);
	fprintf(debug.fp, "action   %16x\n", bit->action);
	fprintf(debug.fp, "pid      %16d\n", bit->pid);
	fprintf(debug.fp, "device   %16d\n", bit->device);
	fprintf(debug.fp, "cpu      %16d\n", bit->cpu);
	fprintf(debug.fp, "error    %16d\n", bit->error);
	fprintf(debug.fp, "pdu_len  %16d\n", bit->pdu_len);

	fprintf(debug.fp, "order    %16ld\n", t->sequence);
}

static void dump_bits(struct trace *t1, struct trace *t2, const char *descr)
{
	struct blk_io_trace *bit1 = &t1->bit;
	struct blk_io_trace *bit2 = &t2->bit;

	if (!debug.fn)
		return;

	fprintf(debug.fp, "--- %s ---\n", descr);
	fprintf(debug.fp, "magic    %16d %16d\n", bit1->magic, bit2->magic);
	fprintf(debug.fp, "sequence %16d %16d\n",
		bit1->sequence, bit2->sequence);
	fprintf(debug.fp, "time     %16ld %16ld\n",
		(unsigned long)bit1->time, (unsigned long)bit2->time);
	fprintf(debug.fp, "sector   %16ld %16ld\n",
		(unsigned long)bit1->sector, (unsigned long)bit2->sector);
	fprintf(debug.fp, "bytes    %16d %16d\n", bit1->bytes, bit2->bytes);
	fprintf(debug.fp, "action   %16x %16x\n", bit1->action, bit2->action);
	fprintf(debug.fp, "pid      %16d %16d\n", bit1->pid, bit2->pid);
	fprintf(debug.fp, "device   %16d %16d\n", bit1->device, bit2->device);
	fprintf(debug.fp, "cpu      %16d %16d\n", bit1->cpu, bit2->cpu);
	fprintf(debug.fp, "error    %16d %16d\n", bit1->error, bit2->error);
	fprintf(debug.fp, "pdu_len  %16d %16d\n", bit1->pdu_len, bit2->pdu_len);

	fprintf(debug.fp, "order    %16ld %16ld\n", t1->sequence, t2->sequence);
}

static struct dstat *blkiomon_alloc_dstat(void)
{
	struct dstat *dstat;

	if (vacant_dstats_list) {
		dstat = vacant_dstats_list;
		vacant_dstats_list = dstat->next;
	} else
		dstat = malloc(sizeof(*dstat));
	if (!dstat) {
		fprintf(stderr,
			"blkiomon: could not allocate device statistic");
		return NULL;
	}

	blkiomon_stat_init(&dstat->msg.stat);
	return dstat;
}

static struct dstat *blkiomon_find_dstat(struct rb_search *search, __u32 device)
{
	struct rb_node **p = &(dstat_tree[dstat_curr].rb_node);
	struct rb_node *parent = NULL;
	struct dstat *dstat;

	while (*p) {
		parent = *p;

		dstat = rb_entry(parent, struct dstat, node);

		if (dstat->msg.stat.device < device)
			p = &(*p)->rb_left;
		else if (dstat->msg.stat.device > device)
			p = &(*p)->rb_right;
		else
			return dstat;
	}
	search->node_ptr = p;
	search->parent = parent;
	return NULL;
}

static struct dstat *blkiomon_get_dstat(__u32 device)
{
	struct dstat *dstat;
	struct rb_search search = { 0, };

	pthread_mutex_lock(&dstat_mutex);

	dstat = blkiomon_find_dstat(&search, device);
	if (dstat)
		goto out;

	dstat = blkiomon_alloc_dstat();
	if (!dstat)
		goto out;

	dstat->msg.stat.device = device;

	rb_link_node(&dstat->node, search.parent, search.node_ptr);
	rb_insert_color(&dstat->node, &dstat_tree[dstat_curr]);

	dstat->next = dstat_list[dstat_curr];
	dstat_list[dstat_curr] = dstat;

out:
	pthread_mutex_unlock(&dstat_mutex);
	return dstat;
}

static int blkiomon_output_msg_q(struct dstat *dstat)
{
	if (!msg_q_name)
		return 0;

	dstat->msg.mtype = msg_id;
	return msgsnd(msg_q, &dstat->msg, sizeof(struct blkiomon_stat), 0);
}

static int blkiomon_output_binary(struct dstat *dstat)
{
	struct blkiomon_stat *p = &dstat->msg.stat;

	if (!binary.fn)
		return 0;

	if (fwrite(p, sizeof(*p), 1, binary.fp) != 1)
		goto failed;
	if (binary.pipe && fflush(binary.fp))
		goto failed;
	return 0;

failed:
	fprintf(stderr, "blkiomon: could not write to %s\n", binary.fn);
	fclose(binary.fp);
	binary.fn = NULL;
	return 1;
}

static struct dstat *blkiomon_output(struct dstat *head, struct timespec *ts)
{
	struct dstat *dstat, *tail = NULL;

	for (dstat = head; dstat; dstat = dstat->next) {
		dstat->msg.stat.time = ts->tv_sec;
		blkiomon_stat_print(human.fp, &dstat->msg.stat);
		blkiomon_stat_to_be(&dstat->msg.stat);
		blkiomon_output_binary(dstat);
		blkiomon_output_msg_q(dstat);
		tail = dstat;
	}
	return tail;
}

static void *blkiomon_interval(void *data)
{
	struct timespec wake, r;
	struct dstat *head, *tail;
	int finished;

	clock_gettime(CLOCK_REALTIME, &wake);

	while (1) {
		wake.tv_sec += interval;
		if (clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &wake, &r)) {
			fprintf(stderr, "blkiomon: interrupted sleep");
			continue;
		}

		/* grab tree and make data gatherer build up another tree */
		pthread_mutex_lock(&dstat_mutex);
		finished = dstat_curr;
		dstat_curr = dstat_curr ? 0 : 1;
		pthread_mutex_unlock(&dstat_mutex);

		head = dstat_list[finished];
		if (!head)
			continue;
		dstat_list[finished] = NULL;
		dstat_tree[finished] = RB_ROOT;
		tail = blkiomon_output(head, &wake);

		pthread_mutex_lock(&dstat_mutex);
		tail->next = vacant_dstats_list;
		vacant_dstats_list = head;
		pthread_mutex_unlock(&dstat_mutex);
	}
	return data;
}

#define BLK_DATADIR(a) (((a) >> BLK_TC_SHIFT) & (BLK_TC_READ | BLK_TC_WRITE))

static int blkiomon_account(struct blk_io_trace *bit_d,
			    struct blk_io_trace *bit_c)
{
	struct dstat *dstat;
	struct blkiomon_stat *p;
	__u64 d2c = (bit_c->time - bit_d->time) / 1000; /* ns -> us */
	__u32 size = bit_d->bytes;
	__u64 thrput = size * 1000 / d2c;

	dstat = blkiomon_get_dstat(bit_d->device);
	if (!dstat)
		return 1;
	p = &dstat->msg.stat;

	if (BLK_DATADIR(bit_c->action) & BLK_TC_READ) {
		minmax_account(&p->thrput_r, thrput);
		minmax_account(&p->size_r, size);
		minmax_account(&p->d2c_r, d2c);
	} else if (BLK_DATADIR(bit_c->action) & BLK_TC_WRITE) {
		minmax_account(&p->thrput_w, thrput);
		minmax_account(&p->size_w, size);
		minmax_account(&p->d2c_w, d2c);
	} else
		p->bidir++;

	histlog2_account(p->size_hist, size, &size_hist);
	histlog2_account(p->d2c_hist, d2c, &d2c_hist);
	return 0;
}

static struct trace *blkiomon_alloc_trace(void)
{
	struct trace *t = vacant_traces_list;
	if (t) {
		vacant_traces_list = t->next;
		vacant_traces--;
	} else
		t = malloc(sizeof(*t));
	memset(t, 0, sizeof(*t));
	return t;
}

static void blkiomon_free_trace(struct trace *t)
{
	if (vacant_traces < 256) {
		t->next = vacant_traces_list;
		vacant_traces_list = t;
		vacant_traces++;
	} else
		free(t);
}

static int action(int a)
{
	int bits = BLK_TC_WRITE | BLK_TC_READ | BLK_TC_FS | BLK_TC_PC;
	return a & (BLK_TC_ACT(bits));
}

static void blkiomon_store_trace(struct trace *t)
{
	int i = t->bit.sector % TRACE_HASH_SIZE;

	t->next = thash[i];
	thash[i] = t;
}

static struct trace *blkiomon_fetch_trace(struct blk_io_trace *bit)
{
	int i = bit->sector % TRACE_HASH_SIZE;
	struct trace *t, *prev = NULL;

	for (t = thash[i]; t; t = t->next) {
		if (t->bit.device == bit->device &&
		    t->bit.sector == bit->sector &&
		    action(t->bit.action) == action(bit->action)) {
			if (prev)
				prev->next = t->next;
			else
				thash[i] = t->next;
			return t;
		}
		prev = t;
	}
	return NULL;
}

static struct trace *blkiomon_do_trace(struct trace *t)
{
	struct trace *t_stored, *t_old, *t_young;

	/* store trace if there is no match yet */
	t_stored = blkiomon_fetch_trace(&t->bit);
	if (!t_stored) {
		blkiomon_store_trace(t);
		return blkiomon_alloc_trace();
	}

	/* figure out older trace and younger trace */
	if (t_stored->bit.time < t->bit.time) {
		t_old = t_stored;
		t_young = t;
	} else {
		t_old = t;
		t_young = t_stored;
	}

	/* we need an older D trace and a younger C trace */
	if (t_old->bit.action & BLK_TC_ACT(BLK_TC_ISSUE) &&
	    t_young->bit.action & BLK_TC_ACT(BLK_TC_COMPLETE)) {
		/* matching D and C traces - update statistics */
		match++;
		blkiomon_account(&t_old->bit, &t_young->bit);
		blkiomon_free_trace(t_stored);
		return t;
	}

	/* no matching D and C traces - keep more recent trace */
	dump_bits(t_old, t_young, "mismatch");
	mismatch++;
	blkiomon_store_trace(t_young);
	return t_old;
}

static int blkiomon_dump_drvdata(struct blk_io_trace *bit, void *pdu_buf)
{
	if (!drvdata.fn)
		return 0;

	if (fwrite(bit, sizeof(*bit), 1, drvdata.fp) != 1)
		goto failed;
	if (fwrite(pdu_buf, bit->pdu_len, 1, drvdata.fp) != 1)
		goto failed;
	if (drvdata.pipe && fflush(drvdata.fp))
		goto failed;
	return 0;

failed:
	fprintf(stderr, "blkiomon: could not write to %s\n", drvdata.fn);
	fclose(drvdata.fp);
	drvdata.fn = NULL;
	return 1;
}

static int blkiomon_do_fifo(void)
{
	struct trace *t;
	struct blk_io_trace *bit;
	void *pdu_buf = NULL;

	t = blkiomon_alloc_trace();
	if (!t)
		return 1;
	bit = &t->bit;

	while (up) {
		if (fread(bit, sizeof(*bit), 1, ifp) != 1) {
			if (!feof(ifp))
				fprintf(stderr,
					"blkiomon: could not read trace");
			break;
		}
		if (ferror(ifp)) {
			clearerr(ifp);
			fprintf(stderr, "blkiomon: error while reading trace");
			break;
		}

		if (data_is_native == -1 && check_data_endianness(bit->magic)) {
			fprintf(stderr, "blkiomon: endianess problem\n");
			break;
		}

		/* endianess */
		trace_to_cpu(bit);
		if (verify_trace(bit)) {
			fprintf(stderr, "blkiomon: bad trace\n");
			break;
		}

		/* read additional trace payload */
		if (bit->pdu_len) {
			pdu_buf = realloc(pdu_buf, bit->pdu_len);
			if (fread(pdu_buf, bit->pdu_len, 1, ifp) != 1) {
				clearerr(ifp);
				fprintf(stderr, "blkiomon: could not read payload\n");
				break;
			}
		}

		t->sequence = sequence++;

		/* forward low-level device driver trace to other tool */
		if (bit->action & BLK_TC_ACT(BLK_TC_DRV_DATA)) {
			driverdata++;
			if (blkiomon_dump_drvdata(bit, pdu_buf)) {
				fprintf(stderr, "blkiomon: could not send trace\n");
				break;
			}
			continue;
		}

		if (!(bit->action & BLK_TC_ACT(BLK_TC_ISSUE | BLK_TC_COMPLETE)))
			continue;

		/* try to find matching trace and update statistics */
		t = blkiomon_do_trace(t);
		if (!t) {
			fprintf(stderr, "blkiomon: could not alloc trace\n");
			break;
		}
		bit = &t->bit;
		/* t and bit will be recycled for next incoming trace */
	}
	blkiomon_free_trace(t);
	free(pdu_buf);
	return 0;
}

static int blkiomon_open_output(struct output *out)
{
	int mode, vbuf_size;

	if (!out->fn)
		return 0;

	if (!strcmp(out->fn, "-")) {
		out->fp = fdopen(STDOUT_FILENO, "w");
		mode = _IOLBF;
		vbuf_size = 4096;
		out->pipe = 1;
	} else {
		out->fp = fopen(out->fn, "w");
		mode = _IOFBF;
		vbuf_size = 128 * 1024;
		out->pipe = 0;
	}
	if (!out->fp)
		goto failed;
	out->buf = malloc(128 * 1024);
	if (setvbuf(out->fp, out->buf, mode, vbuf_size))
		goto failed;
	return 0;

failed:
	fprintf(stderr, "blkiomon: could not write to %s\n", out->fn);
	out->fn = NULL;
	free(out->buf);
	return 1;
}

static int blkiomon_open_msg_q(void)
{
	key_t key;

	if (!msg_q_name)
		return 0;
	if (!msg_q_id || msg_id <= 0)
		return 1;
	key = ftok(msg_q_name, msg_q_id);
	if (key == -1)
		return 1;
	while (up) {
		msg_q = msgget(key, S_IRWXU);
		if (msg_q >= 0)
			break;
	}
	return (msg_q >= 0 ? 0 : -1);
}

static void blkiomon_debug(void)
{
	int i;
	struct trace *t;

	if (!debug.fn)
		return;

	for (i = 0; i < TRACE_HASH_SIZE; i++)
		for (t = thash[i]; t; t = t->next) {
			dump_bit(t, "leftover");
			leftover++;
		}

	fprintf(debug.fp, "%ld leftover, %ld match, %ld mismatch, "
		"%ld driverdata, %ld overall\n",
		leftover, match, mismatch, driverdata, sequence);
}

#define S_OPTS "b:d:D:h:I:Q:q:m:V"

static char usage_str[] = "\n\nblkiomon " \
	"-I <interval>       | --interval=<interval>\n" \
	"[ -h <file>         | --human-readable=<file> ]\n" \
	"[ -b <file>         | --binary=<file> ]\n" \
	"[ -d <file>         | --dump-lldd=<file> ]\n" \
	"[ -D <file>         | --debug=<file> ]\n" \
	"[ -Q <path name>    | --msg-queue=<path name>]\n" \
	"[ -q <msg queue id> | --msg-queue-id=<msg queue id>]\n" \
	"[ -m <msg id>       | --msg-id=<msg id>]\n" \
	"[ -V                | --version ]\n\n" \
	"\t-I   Sample interval.\n" \
	"\t-h   Human-readable output file.\n" \
	"\t-b   Binary output file.\n" \
	"\t-d   Output file for data emitted by low level device driver.\n" \
	"\t-D   Output file for debugging data.\n" \
	"\t-Qqm Output to message queue using given ID for messages.\n" \
	"\t-V   Print program version.\n\n";

static struct option l_opts[] = {
	{
		.name = "human-readable",
		.has_arg = required_argument,
		.flag = NULL,
		.val = 'h'
	},
	{
		.name = "binary",
		.has_arg = required_argument,
		.flag = NULL,
		.val = 'b'
	},
	{
		.name = "dump-lldd",
		.has_arg = required_argument,
		.flag = NULL,
		.val = 'd'
	},
	{
		.name = "debug",
		.has_arg = required_argument,
		.flag = NULL,
		.val = 'D'
	},
	{
		.name = "interval",
		.has_arg = required_argument,
		.flag = NULL,
		.val = 'I'
	},
	{
		.name = "msg-queue",
		.has_arg = required_argument,
		.flag = NULL,
		.val = 'Q'
	},
	{
		.name = "msg-queue-id",
		.has_arg = required_argument,
		.flag = NULL,
		.val = 'q'
	},
	{
		.name = "msg-id",
		.has_arg = required_argument,
		.flag = NULL,
		.val = 'm'
	},
	{
		.name = "version",
		.has_arg = no_argument,
		.flag = NULL,
		.val = 'V'
	},
	{
		.name = NULL,
	}
};

static void blkiomon_signal(int signal)
{
	fprintf(stderr, "blkiomon: terminated by signal\n");
	up = signal & 0;
}

int main(int argc, char *argv[])
{
	int c;

	signal(SIGALRM, blkiomon_signal);
	signal(SIGINT, blkiomon_signal);
	signal(SIGTERM, blkiomon_signal);
	signal(SIGQUIT, blkiomon_signal);

	while ((c = getopt_long(argc, argv, S_OPTS, l_opts, NULL)) != -1) {
		switch (c) {
		case 'h':
			human.fn = optarg;
			break;
		case 'b':
			binary.fn = optarg;
			break;
		case 'd':
			drvdata.fn = optarg;
			break;
		case 'D':
			debug.fn = optarg;
			break;
		case 'I':
			interval = atoi(optarg);
			break;
		case 'Q':
			msg_q_name = optarg;
			break;
		case 'q':
			msg_q_id = atoi(optarg);
			break;
		case 'm':
			msg_id = atoi(optarg);
			break;
		case 'V':
			printf("%s version %s\n", argv[0], blkiomon_version);
			return 0;
		default:
			fprintf(stderr, "Usage: %s", usage_str);
			return 1;
		}
	}

	if (interval <= 0) {
		fprintf(stderr, "Usage: %s", usage_str);
		return 1;
	}

	ifp = fdopen(STDIN_FILENO, "r");
	if (!ifp) {
		perror("blkiomon: could not open stdin for reading");
		return 1;
	}

	if (blkiomon_open_output(&human))
		return 1;
	if (blkiomon_open_output(&binary))
		return 1;
	if (blkiomon_open_output(&drvdata))
		return 1;
	if (blkiomon_open_output(&debug))
		return 1;
	if (blkiomon_open_msg_q())
		return 1;

	if (pthread_create(&interval_thread, NULL, blkiomon_interval, NULL)) {
		fprintf(stderr, "blkiomon: could not create thread");
		return 1;
	}

	blkiomon_do_fifo();

	blkiomon_debug();
	return 0;
}
Commit	Line	Data
cc19ddd6 MP	1	/*
	2	* I/O monitor based on block queue trace data
	3	*
	4	* Copyright IBM Corp. 2008
	5	*
	6	* Author(s): Martin Peschke <mp3@de.ibm.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*/
	22
	23	#include <sys/types.h>
	24	#include <sys/stat.h>
	25	#include <fcntl.h>
	26	#include <unistd.h>
	27	#include <stdio.h>
	28	#include <stdlib.h>
	29	#include <string.h>
	30	#include <signal.h>
	31	#include <getopt.h>
	32	#include <errno.h>
	33	#include <locale.h>
	34	#include <libgen.h>
	35	#include <sys/msg.h>
	36	#include <pthread.h>
	37	#include <time.h>
	38
	39	#include "blktrace.h"
	40	#include "rbtree.h"
	41	#include "jhash.h"
	42	#include "blkiomon.h"
	43
	44	struct trace {
	45	struct blk_io_trace bit;
	46	struct rb_node node;
	47	struct trace *next;
	48	long sequence;
	49	};
	50
	51	struct rb_search {
	52	struct rb_node **node_ptr;
	53	struct rb_node *parent;
	54	};
	55
	56	struct dstat_msg {
	57	long mtype;
	58	struct blkiomon_stat stat;
	59	};
	60
	61	struct dstat {
	62	struct dstat_msg msg;
	63	struct rb_node node;
	64	struct dstat *next;
65	};
66
67	struct output {
68	char *fn;
69	FILE *fp;
70	char *buf;
71	int pipe;
72	};
73
af90543f	74	static char blkiomon_version[] = "0.3";
cc19ddd6 MP	75
	76	static FILE *ifp;
	77	static int interval = -1;
	78
	79	static struct trace *vacant_traces_list = NULL;
	80	static int vacant_traces = 0;
cc19ddd6 MP	81
	82	#define TRACE_HASH_SIZE 128
	83	struct trace *thash[TRACE_HASH_SIZE] = {};
	84
	85	static struct dstat *vacant_dstats_list = NULL;
	86	static struct rb_root dstat_tree[2] = { RB_ROOT, RB_ROOT };
	87	static struct dstat *dstat_list[2] = {};
	88	static int dstat_curr = 0;
	89
3bc3451b	90	static struct output drvdata, human, binary, debug;
cc19ddd6 MP	91
	92	static char *msg_q_name = NULL;
	93	static int msg_q_id = -1, msg_q = -1;
	94	static long msg_id = -1;
	95
	96	static pthread_t interval_thread;
	97	static pthread_mutex_t dstat_mutex = PTHREAD_MUTEX_INITIALIZER;
	98
	99	int data_is_native = -1;
	100
	101	static int up = 1;
	102
	103	/* debugging */
	104	static long leftover = 0, driverdata = 0, match = 0, mismatch = 0, sequence = 0;
	105
	106	static void dump_bit(struct trace t, const char descr)
	107	{
	108	struct blk_io_trace *bit = &t->bit;
	109
	110	if (!debug.fn)
	111	return;
	112
	113	fprintf(debug.fp, "--- %s ---\n", descr);
	114	fprintf(debug.fp, "magic %16d\n", bit->magic);
	115	fprintf(debug.fp, "sequence %16d\n", bit->sequence);
	116	fprintf(debug.fp, "time %16ld\n", (unsigned long)bit->time);
	117	fprintf(debug.fp, "sector %16ld\n", (unsigned long)bit->sector);
	118	fprintf(debug.fp, "bytes %16d\n", bit->bytes);
	119	fprintf(debug.fp, "action %16x\n", bit->action);
	120	fprintf(debug.fp, "pid %16d\n", bit->pid);
	121	fprintf(debug.fp, "device %16d\n", bit->device);
	122	fprintf(debug.fp, "cpu %16d\n", bit->cpu);
	123	fprintf(debug.fp, "error %16d\n", bit->error);
	124	fprintf(debug.fp, "pdu_len %16d\n", bit->pdu_len);
	125
	126	fprintf(debug.fp, "order %16ld\n", t->sequence);
	127	}
	128
	129	static void dump_bits(struct trace t1, struct trace t2, const char *descr)
	130	{
	131	struct blk_io_trace *bit1 = &t1->bit;
	132	struct blk_io_trace *bit2 = &t2->bit;
	133
	134	if (!debug.fn)
	135	return;
	136
	137	fprintf(debug.fp, "--- %s ---\n", descr);
	138	fprintf(debug.fp, "magic %16d %16d\n", bit1->magic, bit2->magic);
	139	fprintf(debug.fp, "sequence %16d %16d\n",
	140	bit1->sequence, bit2->sequence);
	141	fprintf(debug.fp, "time %16ld %16ld\n",
	142	(unsigned long)bit1->time, (unsigned long)bit2->time);
	143	fprintf(debug.fp, "sector %16ld %16ld\n",
	144	(unsigned long)bit1->sector, (unsigned long)bit2->sector);
	145	fprintf(debug.fp, "bytes %16d %16d\n", bit1->bytes, bit2->bytes);
	146	fprintf(debug.fp, "action %16x %16x\n", bit1->action, bit2->action);
	147	fprintf(debug.fp, "pid %16d %16d\n", bit1->pid, bit2->pid);
	148	fprintf(debug.fp, "device %16d %16d\n", bit1->device, bit2->device);
	149	fprintf(debug.fp, "cpu %16d %16d\n", bit1->cpu, bit2->cpu);
	150	fprintf(debug.fp, "error %16d %16d\n", bit1->error, bit2->error);
	151	fprintf(debug.fp, "pdu_len %16d %16d\n", bit1->pdu_len, bit2->pdu_len);
	152
	153	fprintf(debug.fp, "order %16ld %16ld\n", t1->sequence, t2->sequence);
	154	}
155
156	static struct dstat *blkiomon_alloc_dstat(void)
157	{
158	struct dstat *dstat;
159
160	if (vacant_dstats_list) {
161	dstat = vacant_dstats_list;
162	vacant_dstats_list = dstat->next;
163	} else
164	dstat = malloc(sizeof(*dstat));
165	if (!dstat) {
9b26a3a8 MP	166	fprintf(stderr,
9b26a3a8 MP	167	"blkiomon: could not allocate device statistic");
cc19ddd6 MP	168	return NULL;
	169	}
	170
61165962	171	blkiomon_stat_init(&dstat->msg.stat);
cc19ddd6 MP	172	return dstat;
	173	}
	174
	175	static struct dstat blkiomon_find_dstat(struct rb_search search, __u32 device)
	176	{
	177	struct rb_node **p = &(dstat_tree[dstat_curr].rb_node);
	178	struct rb_node *parent = NULL;
	179	struct dstat *dstat;
	180
	181	while (*p) {
	182	parent = *p;
	183
	184	dstat = rb_entry(parent, struct dstat, node);
	185
	186	if (dstat->msg.stat.device < device)
	187	p = &(*p)->rb_left;
	188	else if (dstat->msg.stat.device > device)
	189	p = &(*p)->rb_right;
	190	else
	191	return dstat;
	192	}
	193	search->node_ptr = p;
	194	search->parent = parent;
	195	return NULL;
	196	}
	197
	198	static struct dstat *blkiomon_get_dstat(__u32 device)
	199	{
	200	struct dstat *dstat;
dd093eb1	201	struct rb_search search = { 0, };
cc19ddd6 MP	202
	203	pthread_mutex_lock(&dstat_mutex);
	204
	205	dstat = blkiomon_find_dstat(&search, device);
	206	if (dstat)
	207	goto out;
	208
	209	dstat = blkiomon_alloc_dstat();
	210	if (!dstat)
	211	goto out;
	212
	213	dstat->msg.stat.device = device;
cc19ddd6 MP	214
	215	rb_link_node(&dstat->node, search.parent, search.node_ptr);
	216	rb_insert_color(&dstat->node, &dstat_tree[dstat_curr]);
	217
	218	dstat->next = dstat_list[dstat_curr];
	219	dstat_list[dstat_curr] = dstat;
	220
	221	out:
	222	pthread_mutex_unlock(&dstat_mutex);
	223	return dstat;
	224	}
	225
	226	static int blkiomon_output_msg_q(struct dstat *dstat)
	227	{
	228	if (!msg_q_name)
	229	return 0;
	230
	231	dstat->msg.mtype = msg_id;
	232	return msgsnd(msg_q, &dstat->msg, sizeof(struct blkiomon_stat), 0);
	233	}
	234
	235	static int blkiomon_output_binary(struct dstat *dstat)
	236	{
	237	struct blkiomon_stat *p = &dstat->msg.stat;
	238
	239	if (!binary.fn)
	240	return 0;
	241
	242	if (fwrite(p, sizeof(*p), 1, binary.fp) != 1)
	243	goto failed;
	244	if (binary.pipe && fflush(binary.fp))
	245	goto failed;
	246	return 0;
	247
	248	failed:
	249	fprintf(stderr, "blkiomon: could not write to %s\n", binary.fn);
	250	fclose(binary.fp);
	251	binary.fn = NULL;
	252	return 1;
	253	}
	254
	255	static struct dstat blkiomon_output(struct dstat head, struct timespec *ts)
	256	{
	257	struct dstat dstat, tail = NULL;
	258
	259	for (dstat = head; dstat; dstat = dstat->next) {
	260	dstat->msg.stat.time = ts->tv_sec;
	261	blkiomon_stat_print(human.fp, &dstat->msg.stat);
	262	blkiomon_stat_to_be(&dstat->msg.stat);
	263	blkiomon_output_binary(dstat);
	264	blkiomon_output_msg_q(dstat);
	265	tail = dstat;
	266	}
	267	return tail;
	268	}
	269
	270	static void blkiomon_interval(void data)
	271	{
	272	struct timespec wake, r;
	273	struct dstat head, tail;
	274	int finished;
	275
	276	clock_gettime(CLOCK_REALTIME, &wake);
	277
278	while (1) {
279	wake.tv_sec += interval;
280	if (clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &wake, &r)) {
9b26a3a8	281	fprintf(stderr, "blkiomon: interrupted sleep");
cc19ddd6 MP	282	continue;
	283	}
	284
	285	/* grab tree and make data gatherer build up another tree */
	286	pthread_mutex_lock(&dstat_mutex);
	287	finished = dstat_curr;
	288	dstat_curr = dstat_curr ? 0 : 1;
	289	pthread_mutex_unlock(&dstat_mutex);
	290
	291	head = dstat_list[finished];
	292	if (!head)
	293	continue;
	294	dstat_list[finished] = NULL;
	295	dstat_tree[finished] = RB_ROOT;
	296	tail = blkiomon_output(head, &wake);
	297
	298	pthread_mutex_lock(&dstat_mutex);
	299	tail->next = vacant_dstats_list;
	300	vacant_dstats_list = head;
	301	pthread_mutex_unlock(&dstat_mutex);
	302	}
	303	return data;
	304	}
	305
	306	#define BLK_DATADIR(a) (((a) >> BLK_TC_SHIFT) & (BLK_TC_READ \| BLK_TC_WRITE))
	307
	308	static int blkiomon_account(struct blk_io_trace *bit_d,
	309	struct blk_io_trace *bit_c)
	310	{
	311	struct dstat *dstat;
	312	struct blkiomon_stat *p;
	313	__u64 d2c = (bit_c->time - bit_d->time) / 1000; /* ns -> us */
	314	__u32 size = bit_d->bytes;
53cab5f5	315	__u64 thrput = size * 1000 / d2c;
cc19ddd6 MP	316
	317	dstat = blkiomon_get_dstat(bit_d->device);
	318	if (!dstat)
	319	return 1;
	320	p = &dstat->msg.stat;
	321
29ec9a38	322	if (BLK_DATADIR(bit_c->action) & BLK_TC_READ) {
53cab5f5	323	minmax_account(&p->thrput_r, thrput);
29ec9a38 MP	324	minmax_account(&p->size_r, size);
	325	minmax_account(&p->d2c_r, d2c);
	326	} else if (BLK_DATADIR(bit_c->action) & BLK_TC_WRITE) {
53cab5f5	327	minmax_account(&p->thrput_w, thrput);
29ec9a38 MP	328	minmax_account(&p->size_w, size);
	329	minmax_account(&p->d2c_w, d2c);
	330	} else
cc19ddd6 MP	331	p->bidir++;
	332
	333	histlog2_account(p->size_hist, size, &size_hist);
	334	histlog2_account(p->d2c_hist, d2c, &d2c_hist);
cc19ddd6 MP	335	return 0;
	336	}
	337
	338	static struct trace *blkiomon_alloc_trace(void)
	339	{
	340	struct trace *t = vacant_traces_list;
	341	if (t) {
	342	vacant_traces_list = t->next;
	343	vacant_traces--;
	344	} else
	345	t = malloc(sizeof(*t));
	346	memset(t, 0, sizeof(*t));
	347	return t;
	348	}
	349
	350	static void blkiomon_free_trace(struct trace *t)
	351	{
	352	if (vacant_traces < 256) {
	353	t->next = vacant_traces_list;
	354	vacant_traces_list = t;
	355	vacant_traces++;
	356	} else
	357	free(t);
	358	}
	359
	360	static int action(int a)
	361	{
	362	int bits = BLK_TC_WRITE \| BLK_TC_READ \| BLK_TC_FS \| BLK_TC_PC;
	363	return a & (BLK_TC_ACT(bits));
	364	}
	365
	366	static void blkiomon_store_trace(struct trace *t)
	367	{
	368	int i = t->bit.sector % TRACE_HASH_SIZE;
	369
	370	t->next = thash[i];
	371	thash[i] = t;
	372	}
	373
	374	static struct trace blkiomon_fetch_trace(struct blk_io_trace bit)
	375	{
	376	int i = bit->sector % TRACE_HASH_SIZE;
	377	struct trace t, prev = NULL;
	378
	379	for (t = thash[i]; t; t = t->next) {
	380	if (t->bit.device == bit->device &&
	381	t->bit.sector == bit->sector &&
	382	action(t->bit.action) == action(bit->action)) {
	383	if (prev)
	384	prev->next = t->next;
	385	else
	386	thash[i] = t->next;
	387	return t;
	388	}
	389	prev = t;
	390	}
	391	return NULL;
	392	}
	393
	394	static struct trace blkiomon_do_trace(struct trace t)
	395	{
	396	struct trace t_stored, t_old, *t_young;
	397
	398	/* store trace if there is no match yet */
399	t_stored = blkiomon_fetch_trace(&t->bit);
400	if (!t_stored) {
401	blkiomon_store_trace(t);
402	return blkiomon_alloc_trace();
403	}
404
405	/* figure out older trace and younger trace */
406	if (t_stored->bit.time < t->bit.time) {
407	t_old = t_stored;
408	t_young = t;
409	} else {
410	t_old = t;
411	t_young = t_stored;
412	}
413
414	/* we need an older D trace and a younger C trace */
415	if (t_old->bit.action & BLK_TC_ACT(BLK_TC_ISSUE) &&
416	t_young->bit.action & BLK_TC_ACT(BLK_TC_COMPLETE)) {
417	/* matching D and C traces - update statistics */
418	match++;
419	blkiomon_account(&t_old->bit, &t_young->bit);
420	blkiomon_free_trace(t_stored);
421	return t;
422	}
423
424	/* no matching D and C traces - keep more recent trace */
425	dump_bits(t_old, t_young, "mismatch");
426	mismatch++;
427	blkiomon_store_trace(t_young);
428	return t_old;
429	}
430
3bc3451b MP	431	static int blkiomon_dump_drvdata(struct blk_io_trace bit, void pdu_buf)
	432	{
	433	if (!drvdata.fn)
	434	return 0;
	435
	436	if (fwrite(bit, sizeof(*bit), 1, drvdata.fp) != 1)
	437	goto failed;
	438	if (fwrite(pdu_buf, bit->pdu_len, 1, drvdata.fp) != 1)
	439	goto failed;
	440	if (drvdata.pipe && fflush(drvdata.fp))
	441	goto failed;
	442	return 0;
	443
	444	failed:
	445	fprintf(stderr, "blkiomon: could not write to %s\n", drvdata.fn);
	446	fclose(drvdata.fp);
	447	drvdata.fn = NULL;
	448	return 1;
	449	}
	450
cc19ddd6 MP	451	static int blkiomon_do_fifo(void)
	452	{
	453	struct trace *t;
	454	struct blk_io_trace *bit;
	455	void *pdu_buf = NULL;
	456
	457	t = blkiomon_alloc_trace();
	458	if (!t)
	459	return 1;
	460	bit = &t->bit;
	461
	462	while (up) {
	463	if (fread(bit, sizeof(*bit), 1, ifp) != 1) {
	464	if (!feof(ifp))
	465	fprintf(stderr,
	466	"blkiomon: could not read trace");
	467	break;
	468	}
	469	if (ferror(ifp)) {
	470	clearerr(ifp);
9b26a3a8	471	fprintf(stderr, "blkiomon: error while reading trace");
cc19ddd6 MP	472	break;
	473	}
	474
9b26a3a8 MP	475	if (data_is_native == -1 && check_data_endianness(bit->magic)) {
9b26a3a8 MP	476	fprintf(stderr, "blkiomon: endianess problem\n");
cc19ddd6	477	break;
9b26a3a8	478	}
cc19ddd6 MP	479
	480	/* endianess */
	481	trace_to_cpu(bit);
	482	if (verify_trace(bit)) {
9b26a3a8	483	fprintf(stderr, "blkiomon: bad trace\n");
cc19ddd6 MP	484	break;
	485	}
	486
	487	/* read additional trace payload */
	488	if (bit->pdu_len) {
	489	pdu_buf = realloc(pdu_buf, bit->pdu_len);
	490	if (fread(pdu_buf, bit->pdu_len, 1, ifp) != 1) {
	491	clearerr(ifp);
9b26a3a8	492	fprintf(stderr, "blkiomon: could not read payload\n");
cc19ddd6 MP	493	break;
	494	}
	495	}
	496
	497	t->sequence = sequence++;
	498
3bc3451b MP	499	/* forward low-level device driver trace to other tool */
	500	if (bit->action & BLK_TC_ACT(BLK_TC_DRV_DATA)) {
	501	driverdata++;
9b26a3a8 MP	502	if (blkiomon_dump_drvdata(bit, pdu_buf)) {
9b26a3a8 MP	503	fprintf(stderr, "blkiomon: could not send trace\n");
3bc3451b	504	break;
9b26a3a8	505	}
3bc3451b MP	506	continue;
	507	}
	508
cc19ddd6 MP	509	if (!(bit->action & BLK_TC_ACT(BLK_TC_ISSUE \| BLK_TC_COMPLETE)))
	510	continue;
	511
	512	/* try to find matching trace and update statistics */
	513	t = blkiomon_do_trace(t);
9b26a3a8 MP	514	if (!t) {
9b26a3a8 MP	515	fprintf(stderr, "blkiomon: could not alloc trace\n");
cc19ddd6	516	break;
9b26a3a8	517	}
cc19ddd6 MP	518	bit = &t->bit;
	519	/* t and bit will be recycled for next incoming trace */
	520	}
	521	blkiomon_free_trace(t);
	522	free(pdu_buf);
	523	return 0;
	524	}
	525
	526	static int blkiomon_open_output(struct output *out)
	527	{
	528	int mode, vbuf_size;
	529
	530	if (!out->fn)
	531	return 0;
	532
	533	if (!strcmp(out->fn, "-")) {
	534	out->fp = fdopen(STDOUT_FILENO, "w");
	535	mode = _IOLBF;
	536	vbuf_size = 4096;
	537	out->pipe = 1;
	538	} else {
	539	out->fp = fopen(out->fn, "w");
	540	mode = _IOFBF;
	541	vbuf_size = 128 * 1024;
	542	out->pipe = 0;
	543	}
	544	if (!out->fp)
	545	goto failed;
	546	out->buf = malloc(128 * 1024);
	547	if (setvbuf(out->fp, out->buf, mode, vbuf_size))
	548	goto failed;
	549	return 0;
	550
	551	failed:
	552	fprintf(stderr, "blkiomon: could not write to %s\n", out->fn);
	553	out->fn = NULL;
	554	free(out->buf);
	555	return 1;
	556	}
	557
	558	static int blkiomon_open_msg_q(void)
	559	{
	560	key_t key;
	561
	562	if (!msg_q_name)
	563	return 0;
	564	if (!msg_q_id \|\| msg_id <= 0)
	565	return 1;
	566	key = ftok(msg_q_name, msg_q_id);
	567	if (key == -1)
	568	return 1;
	569	while (up) {
	570	msg_q = msgget(key, S_IRWXU);
	571	if (msg_q >= 0)
	572	break;
	573	}
	574	return (msg_q >= 0 ? 0 : -1);
	575	}
	576
	577	static void blkiomon_debug(void)
	578	{
4bd8e3ba	579	int i;
cc19ddd6 MP	580	struct trace *t;
	581
	582	if (!debug.fn)
	583	return;
	584
4bd8e3ba MP	585	for (i = 0; i < TRACE_HASH_SIZE; i++)
	586	for (t = thash[i]; t; t = t->next) {
	587	dump_bit(t, "leftover");
	588	leftover++;
	589	}
	590
cc19ddd6 MP	591	fprintf(debug.fp, "%ld leftover, %ld match, %ld mismatch, "
	592	"%ld driverdata, %ld overall\n",
	593	leftover, match, mismatch, driverdata, sequence);
	594	}
	595
3bc3451b	596	#define S_OPTS "b:d:D:h:I:Q:q:m:V"
cc19ddd6 MP	597
	598	static char usage_str[] = "\n\nblkiomon " \
	599	"-I <interval> \| --interval=<interval>\n" \
	600	"[ -h <file> \| --human-readable=<file> ]\n" \
	601	"[ -b <file> \| --binary=<file> ]\n" \
cab38cd2	602	"[ -d <file> \| --dump-lldd=<file> ]\n" \
cc19ddd6	603	"[ -D <file> \| --debug=<file> ]\n" \
73ad1727	604	"[ -Q <path name> \| --msg-queue=<path name>]\n" \
cc19ddd6 MP	605	"[ -q <msg queue id> \| --msg-queue-id=<msg queue id>]\n" \
	606	"[ -m <msg id> \| --msg-id=<msg id>]\n" \
	607	"[ -V \| --version ]\n\n" \
	608	"\t-I Sample interval.\n" \
	609	"\t-h Human-readable output file.\n" \
	610	"\t-b Binary output file.\n" \
3bc3451b	611	"\t-d Output file for data emitted by low level device driver.\n" \
cc19ddd6 MP	612	"\t-D Output file for debugging data.\n" \
	613	"\t-Qqm Output to message queue using given ID for messages.\n" \
	614	"\t-V Print program version.\n\n";
	615
	616	static struct option l_opts[] = {
	617	{
	618	.name = "human-readable",
	619	.has_arg = required_argument,
	620	.flag = NULL,
	621	.val = 'h'
	622	},
	623	{
	624	.name = "binary",
	625	.has_arg = required_argument,
	626	.flag = NULL,
	627	.val = 'b'
	628	},
3bc3451b MP	629	{
	630	.name = "dump-lldd",
	631	.has_arg = required_argument,
	632	.flag = NULL,
	633	.val = 'd'
	634	},
cc19ddd6 MP	635	{
	636	.name = "debug",
	637	.has_arg = required_argument,
	638	.flag = NULL,
	639	.val = 'D'
	640	},
	641	{
	642	.name = "interval",
	643	.has_arg = required_argument,
	644	.flag = NULL,
	645	.val = 'I'
	646	},
	647	{
	648	.name = "msg-queue",
	649	.has_arg = required_argument,
	650	.flag = NULL,
	651	.val = 'Q'
	652	},
	653	{
	654	.name = "msg-queue-id",
	655	.has_arg = required_argument,
	656	.flag = NULL,
	657	.val = 'q'
	658	},
	659	{
	660	.name = "msg-id",
	661	.has_arg = required_argument,
	662	.flag = NULL,
	663	.val = 'm'
	664	},
	665	{
	666	.name = "version",
	667	.has_arg = no_argument,
	668	.flag = NULL,
	669	.val = 'V'
	670	},
	671	{
	672	.name = NULL,
	673	}
	674	};
	675
	676	static void blkiomon_signal(int signal)
	677	{
	678	fprintf(stderr, "blkiomon: terminated by signal\n");
	679	up = signal & 0;
	680	}
	681
	682	int main(int argc, char *argv[])
	683	{
	684	int c;
	685
	686	signal(SIGALRM, blkiomon_signal);
	687	signal(SIGINT, blkiomon_signal);
	688	signal(SIGTERM, blkiomon_signal);
	689	signal(SIGQUIT, blkiomon_signal);
	690
	691	while ((c = getopt_long(argc, argv, S_OPTS, l_opts, NULL)) != -1) {
	692	switch (c) {
	693	case 'h':
	694	human.fn = optarg;
	695	break;
	696	case 'b':
	697	binary.fn = optarg;
	698	break;
3bc3451b MP	699	case 'd':
	700	drvdata.fn = optarg;
	701	break;
cc19ddd6 MP	702	case 'D':
	703	debug.fn = optarg;
	704	break;
	705	case 'I':
	706	interval = atoi(optarg);
	707	break;
	708	case 'Q':
	709	msg_q_name = optarg;
	710	break;
	711	case 'q':
	712	msg_q_id = atoi(optarg);
	713	break;
	714	case 'm':
	715	msg_id = atoi(optarg);
	716	break;
	717	case 'V':
	718	printf("%s version %s\n", argv[0], blkiomon_version);
	719	return 0;
	720	default:
	721	fprintf(stderr, "Usage: %s", usage_str);
	722	return 1;
	723	}
	724	}
	725
	726	if (interval <= 0) {
	727	fprintf(stderr, "Usage: %s", usage_str);
	728	return 1;
	729	}
	730
	731	ifp = fdopen(STDIN_FILENO, "r");
	732	if (!ifp) {
	733	perror("blkiomon: could not open stdin for reading");
	734	return 1;
	735	}
	736
	737	if (blkiomon_open_output(&human))
	738	return 1;
	739	if (blkiomon_open_output(&binary))
	740	return 1;
3bc3451b MP	741	if (blkiomon_open_output(&drvdata))
3bc3451b MP	742	return 1;
cc19ddd6 MP	743	if (blkiomon_open_output(&debug))
	744	return 1;
	745	if (blkiomon_open_msg_q())
	746	return 1;
	747
	748	if (pthread_create(&interval_thread, NULL, blkiomon_interval, NULL)) {
9b26a3a8	749	fprintf(stderr, "blkiomon: could not create thread");
cc19ddd6 MP	750	return 1;
	751	}
	752
	753	blkiomon_do_fifo();
	754
	755	blkiomon_debug();
	756	return 0;
	757	}