blktrace: Initial checkin of ported version

Signed-off-by: San Mehat <san@google.com>
diff --git a/btt/iostat.c b/btt/iostat.c
new file mode 100644
index 0000000..8bcd2e5
--- /dev/null
+++ b/btt/iostat.c
@@ -0,0 +1,283 @@
+/*
+ * blktrace output analysis: generate a timeline & gather statistics
+ *
+ * Copyright (C) 2006 Alan D. Brunelle <Alan.Brunelle@hp.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 <stdio.h>
+#include <unistd.h>
+#include "globals.h"
+
+#define INC_STAT(dip, fld)						\
+	do {								\
+		(dip)->stats. fld ++;					\
+		(dip)->all_stats. fld ++;				\
+	} while (0)
+
+#define DEC_STAT(dip, fld)						\
+	do {								\
+		(dip)->stats. fld --;					\
+		(dip)->all_stats. fld --;				\
+	} while (0)
+
+#define ADD_STAT(dip, fld, val)						\
+	do {								\
+		__u64 __v = (val);					\
+		(dip)->stats. fld += __v;				\
+		(dip)->all_stats. fld += __v;				\
+	} while (0)
+
+#define SUB_STAT(dip, fld, val)						\
+	do {								\
+		__u64 __v = (val);					\
+		(dip)->stats. fld -= __v;				\
+		(dip)->all_stats. fld -= __v;				\
+	} while (0)
+
+__u64 last_start, iostat_last_stamp;
+__u64 iostat_interval = 1000000000;
+char *iostat_name = NULL;
+FILE *iostat_ofp = NULL;
+
+static void dump_hdr(void)
+{
+	fprintf(iostat_ofp, "Device:       rrqm/s   wrqm/s     r/s     w/s    "
+			    "rsec/s    wsec/s     rkB/s     wkB/s "
+			    "avgrq-sz avgqu-sz   await   svctm  %%util   Stamp\n");
+}
+
+static void update_tot_qusz(struct d_info *dip, double now)
+{
+	dip->stats.tot_qusz += ((now - dip->stats.last_qu_change) *
+						dip->stats.cur_qusz);
+	dip->all_stats.tot_qusz += ((now - dip->all_stats.last_qu_change) *
+						dip->all_stats.cur_qusz);
+
+	dip->stats.last_qu_change = dip->all_stats.last_qu_change = now;
+}
+
+static void update_idle_time(struct d_info *dip, double now, int force)
+{
+	if (dip->stats.cur_dev == 0 || force) {
+		dip->stats.idle_time += (now - dip->stats.last_dev_change);
+		dip->all_stats.idle_time +=
+				       (now - dip->all_stats.last_dev_change);
+	}
+	dip->stats.last_dev_change = dip->all_stats.last_dev_change = now;
+}
+
+void __dump_stats(__u64 stamp, int all, struct d_info *dip, struct stats_t *asp)
+{
+	char hdr[16];
+	struct stats *sp;
+	double dt, nios, avgrq_sz, p_util, nrqm, await, svctm;
+	double now = TO_SEC(stamp);
+
+	if (all) {
+		dt = (double)stamp / 1.0e9;
+		sp = &dip->all_stats;
+	} else {
+		dt = (double)(stamp-last_start) / 1.0e9;
+		sp = &dip->stats;
+	}
+
+	nios = (double)(sp->ios[0] + sp->ios[1]);
+	nrqm = (double)(sp->rqm[0] + sp->rqm[1]);
+	update_idle_time(dip, now, 1);
+	update_tot_qusz(dip, now);
+
+	if (nios > 0.0) {
+		avgrq_sz = (double)(sp->sec[0] + sp->sec[1]) / nios;
+		svctm = TO_MSEC(sp->svctm) / nios;
+	} else
+		avgrq_sz = svctm = 0.0;
+
+	await = ((nios + nrqm) > 0.0) ? TO_MSEC(sp->wait) / (nios+nrqm) : 0.0;
+	p_util = (sp->idle_time <= dt) ? 100.0 * (1.0 - (sp->idle_time / dt)) :
+	                                 0.0;
+
+	/*
+	 * For AWAIT: nios should be the same as number of inserts
+	 * and we add in nrqm (number of merges), which should give
+	 * us the total number of IOs sent to the block IO layer.
+	 */
+	fprintf(iostat_ofp, "%-11s ", make_dev_hdr(hdr, 11, dip, 1));
+	fprintf(iostat_ofp, "%8.2lf ", (double)sp->rqm[1] / dt);
+	fprintf(iostat_ofp, "%8.2lf ", (double)sp->rqm[0] / dt);
+	fprintf(iostat_ofp, "%7.2lf ", (double)sp->ios[1] / dt);
+	fprintf(iostat_ofp, "%7.2lf ", (double)sp->ios[0] / dt);
+	fprintf(iostat_ofp, "%9.2lf ", (double)sp->sec[1] / dt);
+	fprintf(iostat_ofp, "%9.2lf ", (double)sp->sec[0] / dt);
+	fprintf(iostat_ofp, "%9.2lf ", (double)(sp->sec[1] / 2) / dt);
+	fprintf(iostat_ofp, "%9.2lf ", (double)(sp->sec[0] / 2) / dt);
+	fprintf(iostat_ofp, "%8.2lf ", avgrq_sz);
+	fprintf(iostat_ofp, "%8.2lf ", (double)sp->tot_qusz / dt);
+	fprintf(iostat_ofp, "%7.2lf ", await);
+	fprintf(iostat_ofp, "%7.2lf ", svctm);
+	fprintf(iostat_ofp, "%6.2lf", p_util);
+	if (all)
+		fprintf(iostat_ofp, "%8s\n", "TOTAL");
+	else {
+		fprintf(iostat_ofp, "%8.2lf\n", TO_SEC(stamp));
+		sp->rqm[0] = sp->rqm[1] = 0;
+		sp->ios[0] = sp->ios[1] = 0;
+		sp->sec[0] = sp->sec[1] = 0;
+		sp->wait = sp->svctm = 0;
+
+		sp->tot_qusz = sp->idle_time = 0.0;
+	}
+
+	if (asp) {
+		int i;
+
+		asp->n += 1.0;
+		for (i = 0; i < 2; i++) {
+			asp->rqm_s[i] += ((double)sp->rqm[i] / dt);
+			asp->ios_s[i] += ((double)sp->ios[i] / dt);
+			asp->sec_s[i] += ((double)sp->sec[i] / dt);
+		}
+		asp->avgrq_sz += avgrq_sz;
+		asp->avgqu_sz += (double)sp->tot_qusz / dt;
+		asp->await += await;
+		asp->svctm += svctm;
+		asp->p_util += p_util;
+	}
+}
+
+static void __dump_stats_t(__u64 stamp, struct stats_t *asp, int all)
+{
+	if (asp->n < 2.0) return;	// What's the point?
+
+	fprintf(iostat_ofp, "%-11s ", "TOTAL");
+	fprintf(iostat_ofp, "%8.2lf ", asp->rqm_s[0]);
+	fprintf(iostat_ofp, "%8.2lf ", asp->rqm_s[1]);
+	fprintf(iostat_ofp, "%7.2lf ", asp->ios_s[0]);
+	fprintf(iostat_ofp, "%7.2lf ", asp->ios_s[1]);
+	fprintf(iostat_ofp, "%9.2lf ", asp->sec_s[0]);
+	fprintf(iostat_ofp, "%9.2lf ", asp->sec_s[1]);
+	fprintf(iostat_ofp, "%9.2lf ", asp->sec_s[0] / 2.0);
+	fprintf(iostat_ofp, "%9.2lf ", asp->sec_s[1] / 2.0);
+	fprintf(iostat_ofp, "%8.2lf ", asp->avgrq_sz / asp->n);
+	fprintf(iostat_ofp, "%8.2lf ", asp->avgqu_sz / asp->n);
+	fprintf(iostat_ofp, "%7.2lf ", asp->await / asp->n);
+	fprintf(iostat_ofp, "%7.2lf ", asp->svctm / asp->n);
+	fprintf(iostat_ofp, "%6.2lf", asp->p_util / asp->n);
+	if (all)
+		fprintf(iostat_ofp, "%8s\n", "TOTAL");
+	else 
+		fprintf(iostat_ofp, "%8.2lf\n", TO_SEC(stamp));
+}
+
+void iostat_init(void)
+{
+	last_start = (__u64)-1;
+	if (iostat_ofp)
+		dump_hdr();
+}
+
+void iostat_dump_stats(__u64 stamp, int all)
+{
+	struct d_info *dip;
+	struct stats_t as;
+
+	memset(&as, 0, sizeof(struct stats_t));
+	if (all)
+		dump_hdr();
+
+	if (devices == NULL) {
+		struct list_head *p;
+
+		__list_for_each(p, &all_devs) {
+			dip = list_entry(p, struct d_info, all_head);
+			__dump_stats(stamp, all, dip, &as);
+		}
+	} else {
+		int i;
+		unsigned int mjr, mnr;
+		char *p = devices;
+
+		while (p && ((i = sscanf(p, "%u,%u", &mjr, &mnr)) == 2)) {
+			dip = __dip_find((__u32)((mjr << MINORBITS) | mnr));
+			__dump_stats(stamp, all, dip, &as);
+
+			p = strchr(p, ';');
+			if (p) p++;
+		}
+	}
+
+	__dump_stats_t(stamp, &as, all);
+
+	if (!all && iostat_ofp)
+		fprintf(iostat_ofp, "\n");
+}
+
+void iostat_check_time(__u64 stamp)
+{
+	if (iostat_ofp) {
+		if (last_start == (__u64)-1)
+			last_start = stamp;
+		else if ((stamp - last_start) >= iostat_interval) {
+			iostat_dump_stats(stamp, 0);
+			last_start = stamp;
+		}
+
+		iostat_last_stamp = stamp;
+	}
+}
+
+void iostat_getrq(struct io *iop)
+{
+	update_tot_qusz(iop->dip, TO_SEC(iop->t.time));
+	INC_STAT(iop->dip, cur_qusz);
+}
+
+void iostat_merge(struct io *iop)
+{
+	INC_STAT(iop->dip, rqm[IOP_RW(iop)]);
+}
+
+void iostat_issue(struct io *iop)
+{
+	int rw = IOP_RW(iop);
+	struct d_info *dip = iop->dip;
+	double now = TO_SEC(iop->t.time);
+
+	INC_STAT(dip, ios[rw]);
+	ADD_STAT(dip, sec[rw], iop->t.bytes >> 9);
+
+	update_idle_time(dip, now, 0);
+	INC_STAT(dip, cur_dev);
+}
+
+void iostat_complete(struct io *q_iop, struct io *c_iop)
+{
+	double now = TO_SEC(c_iop->t.time);
+	struct d_info *dip = q_iop->dip;
+
+	if (q_iop->i_time != (__u64)-1)
+		ADD_STAT(c_iop->dip, wait, tdelta(q_iop->i_time,c_iop->t.time));
+	else if (q_iop->m_time != (__u64)-1)
+		ADD_STAT(c_iop->dip, wait, tdelta(q_iop->m_time,c_iop->t.time));
+
+	update_tot_qusz(dip, now);
+	DEC_STAT(dip, cur_qusz);
+
+	update_idle_time(dip, now, 0);
+	DEC_STAT(dip, cur_dev);
+
+	ADD_STAT(dip, svctm, tdelta(q_iop->t.time, c_iop->t.time));
+}