[PATCH] btt: Fixed %utilization computation: idle not being computed right.

Need to adjust last time device was looked at to include sparse times
when we don't have many IOs coming in.

Signed-off-by: Alan D. Brunelle <Alan.Brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/btt/Makefile b/btt/Makefile
index 2d60eedef7d933e135bb8868983746aac07961de..df5096b743668f7e35c26256579d9580ef0f8021 100644 (file)
--- a/btt/Makefile
+++ b/btt/Makefile
@@ -1,7 +1,7 @@
 CC     = gcc
 MYFLAGS = -DLVM_REMAP_WORKAROUND
-#CFLAGS        = -Wall -O2 -W -g
-CFLAGS = -Wall -g -W -UDO_INLINE -DDEBUG
+CFLAGS = -Wall -O2 -W -g
+#CFLAGS        = -Wall -g -W -UDO_INLINE -DDEBUG
 ALL_CFLAGS = $(CFLAGS) -I.. -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64
 PROGS  = btt
 #ELIBS = -lefence

diff --git a/btt/iostat.c b/btt/iostat.c
index 4f375dcd2327ea28afd0888007932da9466d5604..9c345883fb274508c6b42725fb1983810f7b6921 100644 (file)
--- a/btt/iostat.c
+++ b/btt/iostat.c
@@ -22,9 +22,6 @@
 #include <unistd.h>
 #include "globals.h"
 
-#define TO_SEC(nanosec)                ((double)(nanosec) / 1.0e9)
-#define TO_MSEC(nanosec)       (1000.0 * TO_SEC(nanosec))
-
 #define INC_STAT(dip, fld)                                             \
        do {                                                            \
                (dip)->stats. fld ++;                                   \
@@ -93,9 +90,9 @@ void update_tot_qusz(struct d_info *dip, double now)
        dip->stats.last_qu_change = dip->all_stats.last_qu_change = now;
 }
 
-void update_idle_time(struct d_info *dip, double now)
+void update_idle_time(struct d_info *dip, double now, int force)
 {
-       if (dip->stats.cur_dev == 0) {
+       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);
@@ -107,7 +104,7 @@ void __dump_stats(__u64 stamp, int all, struct d_info *dip)
 {
        char hdr[16];
        struct stats *sp;
-       double dt, nios, avgrq_sz, p_util, nrqm;
+       double dt, nios, avgrq_sz, p_util, nrqm, await, svctm;
        double now = TO_SEC(stamp);
 
        if (all) {
@@ -121,42 +118,49 @@ void __dump_stats(__u64 stamp, int all, struct d_info *dip)
 
        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) {
-               update_idle_time(dip, now);
-               update_tot_qusz(dip, now);
                avgrq_sz = (double)(sp->sec[0] + sp->sec[1]) / nios;
-               p_util = 100.0 * (1.0 - (sp->idle_time / dt));
-
-               /*
-                * 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));
-               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 ", TO_MSEC(sp->wait) / (nios+nrqm));
-               fprintf(iostat_ofp, "%7.2lf ", TO_MSEC(sp->svctm) / nios);
-               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;
-               }
+               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));
+       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;
        }
 }
 
@@ -187,6 +191,9 @@ void iostat_dump_stats(__u64 stamp, int all)
                        if (p) p++;
                }
        }
+       if (!all && iostat_ofp)
+               fprintf(iostat_ofp, "\n");
+               
 }
 
 void iostat_check_time(__u64 stamp)
@@ -223,7 +230,7 @@ void iostat_issue(struct io *iop)
        INC_STAT(dip, ios[rw]);
        ADD_STAT(dip, sec[rw], iop->t.bytes >> 9);
 
-       update_idle_time(dip, now);
+       update_idle_time(dip, now, 0);
        INC_STAT(dip, cur_dev);
 }
 
@@ -239,7 +246,7 @@ void iostat_complete(struct io *iop)
                update_tot_qusz(dip, now);
                DEC_STAT(dip, cur_qusz);
 
-               update_idle_time(dip, now);
+               update_idle_time(dip, now, 0);
                DEC_STAT(dip, cur_dev);
 
                ADD_STAT(dip, svctm, iop->t.time - d_iop->t.time);