From 75a0ef5d8b4b2c0c80e5951e8e0b65b0958aab15 Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Wed, 13 Apr 2011 09:33:25 -0700
Subject: [PATCH] test - Add random seek/read program

* Add program which reads a random 512 byte block in a device or file
  with 32 concurrent accessors and displays the results.

* make /tmp/rr1 from /usr/src/test/sysperf
---
 test/sysperf/Makefile   |  6 ++-
 test/sysperf/blib.c     |  3 ++
 test/sysperf/randread.c | 96 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 104 insertions(+), 1 deletion(-)
 create mode 100644 test/sysperf/randread.c

diff --git a/test/sysperf/Makefile b/test/sysperf/Makefile
index 752a2f36b5..485f4e8291 100644
--- a/test/sysperf/Makefile
+++ b/test/sysperf/Makefile
@@ -13,7 +13,8 @@ TARGETS=/tmp/sc1 /tmp/sc2 /tmp/sc3 /tmp/sc4 /tmp/sc5 \
 	/tmp/upc1 \
 	/tmp/exec1 /tmp/exec2 \
 	/tmp/mem1 /tmp/mem2 \
-	/tmp/cld1
+	/tmp/cld1 \
+	/tmp/rr1
 
 .if defined(NO_OPTIMIZE)
 COPTFLAGS= -O
@@ -120,5 +121,8 @@ all:	$(TARGETS)
 /tmp/read1: read1.c blib.c
 	$(CC) $(CFLAGS) read1.c blib.c -o /tmp/read1
 
+/tmp/rr1: randread.c blib.c
+	$(CC) $(CFLAGS) randread.c blib.c -o /tmp/rr1
+
 clean:
 	rm -f $(TARGETS)
diff --git a/test/sysperf/blib.c b/test/sysperf/blib.c
index cf09cad4d1..c668a7995b 100644
--- a/test/sysperf/blib.c
+++ b/test/sysperf/blib.c
@@ -41,6 +41,9 @@ stop_timing(long long count, const char *ctl, ...)
 	count,
 	(double)us / (double)count
     );
+
+    tv1 = tv2;
+
     return(0);
 }
 
diff --git a/test/sysperf/randread.c b/test/sysperf/randread.c
new file mode 100644
index 0000000000..f0ce61b519
--- /dev/null
+++ b/test/sysperf/randread.c
@@ -0,0 +1,96 @@
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/file.h>
+#include <sys/errno.h>
+#include <sys/wait.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <machine/atomic.h>
+#include "blib.h"
+
+int
+main(int ac, char **av)
+{
+    char *buf;
+    size_t bytes = 512;
+    off_t limit;
+    int fd;
+    int i;
+    int nprocs = 32;
+    double range = 90.0;
+    volatile int *counterp;
+    int clast;
+    int cnext;
+    int cdelta;
+
+    if (ac < 2 || ac > 5) {
+	fprintf(stderr, "%s <device> [bufsize:512 [range%:90 [nprocs:32]]]\n",
+		av[0]);
+	exit (1);
+    }
+
+    if (ac >= 3) {
+	bytes = (size_t)strtoul(av[2], NULL, 0);
+	if (bytes < 512 || (bytes ^ (bytes - 1)) != ((bytes << 1) - 1)) {
+	    fprintf(stderr, "bytes must be a power of 2 >= 512\n");
+	    exit (1);
+	}
+    }
+    buf = malloc(bytes);
+
+    if (ac >= 4) {
+	range = strtod(av[3], NULL);
+    }
+
+    if (ac >= 5) {
+	nprocs = strtol(av[4], NULL, 0);
+	if (nprocs < 0 || nprocs > 512) {
+	    fprintf(stderr, "absurd nprocs (%d)\n", nprocs);
+	    exit(1);
+	}
+    }
+
+    fd = open(av[1], O_RDONLY);
+    if (fd < 0) {
+	fprintf(stderr, "open %s: %s\n", av[1], strerror(errno));
+	exit (1);
+    }
+
+    lseek(fd, 0L, 2);
+    limit = lseek(fd, 0L, 1);
+    limit = (off_t)((double)limit * range / 100.0);
+    limit &= ~(off_t)(bytes - 1);
+    printf("device %s bufsize %zd limit %4.3fGB nprocs %d\n",
+	av[1], bytes, (double)limit / (1024.0*1024.0*1024.0), nprocs);
+
+    counterp = mmap(NULL, sizeof(int), PROT_READ|PROT_WRITE,
+		    MAP_SHARED|MAP_ANON, -1, 0);
+
+    for (i = 0; i < nprocs; ++i) {
+	if (fork() == 0) {
+	    srandomdev();
+	    for (;;) {
+		long pos = (random() % limit) & ~(off_t)(bytes - 1);
+		lseek(fd, pos, 0);
+		read(fd, buf, bytes);
+		atomic_add_int(counterp, 1);
+	    }
+	}
+    }
+    start_timing();
+    sleep(1);
+    start_timing();
+    clast = *counterp;
+
+    for (;;) {
+	sleep(1);
+	cnext = *counterp;
+	cdelta = cnext - clast;
+	clast = cnext;
+	stop_timing(cdelta, "randread");
+    }
+    return 0;
+}
-- 
2.41.0