From: Michal Sojka <sojkam1@fel.cvut.cz>
Date: Mon, 3 May 2010 15:07:04 +0000 (+0200)
Subject: Add test for O_DIRECT
X-Git-Tag: jsa-paper-casestudy-v2~66
X-Git-Url: https://rtime.felk.cvut.cz/gitweb/frescor/demo.git/commitdiff_plain/62c6beb18bde4c44194b0b6aac330f462fad93ae

Add test for O_DIRECT
---

diff --git a/build/test_o_direct/Makefile b/build/test_o_direct/Makefile
new file mode 100644
index 0000000..710dbf2
--- /dev/null
+++ b/build/test_o_direct/Makefile
@@ -0,0 +1,3 @@
+all: direct
+
+CFLAGS = -Wall -g -O0
diff --git a/build/test_o_direct/direct.c b/build/test_o_direct/direct.c
new file mode 100644
index 0000000..f7e8675
--- /dev/null
+++ b/build/test_o_direct/direct.c
@@ -0,0 +1,134 @@
+#define _GNU_SOURCE
+#define _XOPEN_SOURCE 600
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <malloc.h>
+#include <error.h>
+
+int trace_fd = -1;
+int marker_fd = -1;
+
+#define MAX_PATH 256
+#define _STR(x) #x
+#define STR(x) _STR(x)
+
+#define MARKER(str) write(marker_fd, str, strlen(str));
+
+static const char *find_debugfs(void)
+{
+	static char debugfs[MAX_PATH+1];
+	static int debugfs_found;
+	char type[100];
+	FILE *fp;
+
+	if (debugfs_found)
+		return debugfs;
+
+	if ((fp = fopen("/proc/mounts","r")) == NULL)
+		return NULL;
+
+	while (fscanf(fp, "%*s %"
+		      STR(MAX_PATH)
+		      "s %99s %*s %*d %*d\n",
+		      debugfs, type) == 2) {
+		if (strcmp(type, "debugfs") == 0)
+			break;
+	}
+	fclose(fp);
+
+	if (strcmp(type, "debugfs") != 0)
+		return NULL;
+
+	debugfs_found = 1;
+
+	return debugfs;
+}
+
+void init_ftrace()
+{
+	const char *debugfs;
+	char path[256], pid[10];
+	int pid_fd;
+	
+	debugfs = find_debugfs();
+	if (debugfs) {
+		strcpy(path, debugfs);
+		strcat(path,"/tracing/trace_marker");
+		marker_fd = open(path, O_WRONLY);
+
+		strcpy(path, debugfs);
+		strcat(path,"/tracing/set_ftrace_pid");
+		pid_fd = open(path, O_WRONLY);
+		sprintf(pid, "%d", getpid());
+		if (pid_fd >= 0)
+			write(pid_fd, pid, strlen(pid));
+
+		strcpy(path, debugfs);
+		strcat(path,"/tracing/tracing_on");
+		trace_fd = open(path, O_WRONLY);
+		if (trace_fd >= 0)
+			write(trace_fd, "1", 1);
+	}
+}
+
+int main()
+{
+	int fd, ret;
+	char *buf;
+	size_t pagesize = sysconf(_SC_PAGESIZE);
+
+	buf = memalign(pagesize, pagesize);
+	if (!buf)
+		error(1, errno, "memalign");
+
+	init_ftrace();
+
+	if (marker_fd >= 0)
+		MARKER("Without O_DIRECT");
+
+	fd = open("file", O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR);
+	if (fd < 0)
+		error(1, errno, "open");
+	ret = write(fd, buf, 512);
+	if (ret < 0)
+		error(1, errno, "write");
+	close(fd);
+
+	if (marker_fd)
+		MARKER("With O_DIRECT");
+
+	fd = open("file", O_CREAT | O_TRUNC | O_WRONLY | O_DIRECT, S_IRUSR | S_IWUSR);
+	if (fd < 0)
+		error(1, errno, "open");
+	ret = write(fd, buf, 512);
+	if (ret < 0)
+		error(1, errno, "write");
+	close(fd);
+
+	if (marker_fd)
+		MARKER("Without O_DIRECT and with posix_fadvise");
+
+	fd = open("file", O_CREAT | O_TRUNC | O_WRONLY, S_IRUSR | S_IWUSR);
+	if (fd < 0)
+		error(1, errno, "open");
+	ret = write(fd, buf, 512);
+	if (ret < 0)
+		error(1, errno, "write");
+	ret = posix_fadvise(fd, 0, 512, POSIX_FADV_DONTNEED);
+	if (ret != 0)
+		error(1, ret, "posix_fadvise");
+	close(fd);
+
+	if (marker_fd)
+		MARKER("End");
+
+	if (trace_fd >= 0)
+		write(trace_fd, "0", 1);
+    	return 0;
+}
diff --git a/build/test_o_direct/run.sh b/build/test_o_direct/run.sh
new file mode 100755
index 0000000..945d0d9
--- /dev/null
+++ b/build/test_o_direct/run.sh
@@ -0,0 +1,24 @@
+#!/bin/sh
+DEBUGFS=`grep debugfs /proc/mounts | awk '{ print $2; }'`
+T=$DEBUGFS/tracing
+
+echo 0 > $T/tracing_enabled
+echo function_graph > $T/current_tracer
+echo > $T/trace
+
+echo > $T/set_ftrace_filter
+
+echo > $T/set_graph_function
+echo sys_open sys_write sys_close sys_fadvise64_64 > $T/set_graph_function
+
+echo 1 > $T/events/syscalls/sys_enter_write/enable
+echo 1 > $T/events/syscalls/sys_enter_open/enable
+echo 1 > $T/events/syscalls/sys_enter_close/enable
+
+echo 0 > $T/tracing_on		# We switch tracing on in the program
+echo 1 > $T/tracing_enabled
+
+( exec ./direct )
+
+echo 0 > $T/tracing_enabled
+cp $T/trace  .