[Patch 2/2] 2.6.15-rc1-mm2: disabling the pagecache for doingbenchmarks

From: Dirk Henning Gerdes
Date: Sat Nov 19 2005 - 11:43:03 EST


The module to get acces over the proc-fs

Signed-off-by: Dirk Gerdes <mail@xxxxxxxxxxxxxx>

--
diff -pruN linux-2.6.15-rc1-mm2/block/Kconfig
linux-2.6.15-rc1-mm2-pagecache/block/Kconfig
--- linux-2.6.15-rc1-mm2/block/Kconfig 2005-11-19 12:31:42.000000000
+0100
+++ linux-2.6.15-rc1-mm2-pagecache/block/Kconfig 2005-11-19
13:29:44.000000000 +0100
@@ -23,3 +23,9 @@ config BLK_DEV_IO_TRACE
git://brick.kernel.dk/data/git/blktrace.git

source block/Kconfig.iosched
+
+config PAGECACHE_TOGGLE
+ bool "toggle for using pagecache reading from block-devices"
+ help
+ This is very useful if you would likr to do benchmarks on the
+ performance of the I/O-Schedulers.
diff -pruN linux-2.6.15-rc1-mm2/block/Makefile
linux-2.6.15-rc1-mm2-pagecache/block/Makefile
--- linux-2.6.15-rc1-mm2/block/Makefile 2005-11-19 12:31:42.000000000
+0100
+++ linux-2.6.15-rc1-mm2-pagecache/block/Makefile 2005-11-19
13:29:44.000000000 +0100
@@ -10,3 +10,4 @@ obj-$(CONFIG_IOSCHED_DEADLINE) += deadli
obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o

obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
+obj-$(CONFIG_PAGECACHE_TOGGLE) += pagecache.o
diff -pruN linux-2.6.15-rc1-mm2/block/pagecache.c
linux-2.6.15-rc1-mm2-pagecache/block/pagecache.c
--- linux-2.6.15-rc1-mm2/block/pagecache.c 1970-01-01 01:00:00.000000000
+0100
+++ linux-2.6.15-rc1-mm2-pagecache/block/pagecache.c 2005-11-19
13:29:44.000000000 +0100
@@ -0,0 +1,76 @@
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <asm/uaccess.h>
+//#include <linux/pagecache.h>
+
+
+MODULE_LICENSE("GPL");
+
+extern int pagecache;
+
+
+static struct proc_dir_entry *benchmark_dir,
+ *pagecache_entry;
+
+
+
+
+
+
+static int pagecache_entry_read(char *buf, char **start,off_t
offset,int size, int *eof, void *data)
+{
+ printk("%i__\n",pagecache);
+ int bytes_written = 0;
+ if (pagecache)
+ bytes_written = snprintf(buf, size, "[on] off\n");
+ else
+ bytes_written = snprintf(buf, size, " on [off]\n");
+ return bytes_written;
+}
+
+static int pagecache_entry_write(struct file * instanz, const char
__user *userbuffer, unsigned long count, void *data)
+{
+ char *kernel_buffer;
+ int not_copied;
+
+ kernel_buffer = kmalloc(count, GFP_KERNEL);
+ if (!kernel_buffer)
+ return -ENOMEM;
+ not_copied = copy_from_user(kernel_buffer, userbuffer, count);
+ if (strncmp (kernel_buffer,"on",2)==0){
+ pagecache=1;
+ }
+ else if (strncmp (kernel_buffer,"off",3)==0){
+ pagecache=0;
+ }
+
+ kfree(kernel_buffer);
+ return count-not_copied;
+}
+
+static int __init my_init(void)
+{
+
+
+ benchmark_dir = proc_mkdir("benchmark",NULL);
+ pagecache_entry = create_proc_entry("pagecache",S_IRUGO,
benchmark_dir);
+ if (pagecache_entry){
+ pagecache_entry->read_proc = pagecache_entry_read;
+ pagecache_entry->write_proc = pagecache_entry_write;
+
+ pagecache_entry->data = NULL;
+ }
+
+ return 0;
+}
+static void __exit my_exit(void){
+ if (pagecache_entry) remove_proc_entry("pagecache",benchmark_dir);
+ if (benchmark_dir) remove_proc_entry("benchmark",NULL);
+}
+
+
+module_init(my_init);
+module_exit(my_exit);
+


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/