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Add -c option that calculates the overhead of read I/O ops.

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This commit is contained in:
Søren Schmidt 2004-11-09 12:28:41 +00:00
parent c6dc77e0fe
commit 6a33b3c60b
2 changed files with 49 additions and 3 deletions
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4
usr.sbin/diskinfo/diskinfo.8
View File

@ -54,6 +54,10 @@ If given the
option, the fields will be printed one per line with a descriptive comment.
.Pp
The
.Fl c
option triggers a simple measurement of the I/O read command overhead.
.Pp
The
.Fl t
option triggers a simple and rather naive benchmark of the disks seek
and transfer performance.

48
usr.sbin/diskinfo/diskinfo.c
View File

@ -48,9 +48,10 @@ usage(void)
exit (1);
}
static int opt_t, opt_v;
static int opt_c, opt_t, opt_v;
static void speeddisk(int fd, off_t mediasize, u_int sectorsize);
static void commandtime(int fd, off_t mediasize, u_int sectorsize);
int
main(int argc, char **argv)
@ -60,8 +61,12 @@ main(int argc, char **argv)
off_t mediasize;
u_int sectorsize, fwsectors, fwheads;
while ((ch = getopt(argc, argv, "tv")) != -1) {
while ((ch = getopt(argc, argv, "ctv")) != -1) {
switch (ch) {
case 'c':
opt_c = 1;
opt_v = 1;
break;
case 't':
opt_t = 1;
opt_v = 1;
@ -127,6 +132,8 @@ main(int argc, char **argv)
}
}
printf("\n");
if (opt_c)
commandtime(fd, mediasize, sectorsize);
if (opt_t)
speeddisk(fd, mediasize, sectorsize);
close(fd);
@ -305,6 +312,41 @@ speeddisk(int fd, off_t mediasize, u_int sectorsize)
TR(100 * 1024);
printf("\n");
return;
}
static void
commandtime(int fd, off_t mediasize, u_int sectorsize)
{
double dtmega, dtsector;
int i;
printf("I/O command overhead:\n");
i = mediasize;
rdsect(fd, 0, sectorsize);
T0();
for (i = 0; i < 10; i++)
rdmega(fd);
gettimeofday(&tv2, NULL);
dtmega = (tv2.tv_usec - tv1.tv_usec) / 1e6;
dtmega += (tv2.tv_sec - tv1.tv_sec);
printf("\ttime to read 10MB block %10.6f sec\t= %8.3f msec/sector\n",
dtmega, dtmega*100/2048);
rdsect(fd, 0, sectorsize);
T0();
for (i = 0; i < 20480; i++)
rdsect(fd, 0, sectorsize);
gettimeofday(&tv2, NULL);
dtsector = (tv2.tv_usec - tv1.tv_usec) / 1e6;
dtsector += (tv2.tv_sec - tv1.tv_sec);
printf("\ttime to read 20480 sectors %10.6f sec\t= %8.3f msec/sector\n",
dtsector, dtsector*100/2048);
printf("\tcalculated command overhead\t\t\t= %8.3f msec/sector\n",
(dtsector - dtmega)*100/2048);
printf("\n");
return;
}