[PATCH] s390: debug feature changes

This patch changes the memory allocation method for the s390 debug feature.
Trace buffers had been allocated using the get_free_pages() function before.
Therefore it was not possible to get big memory areas in a running system due
to memory fragmentation.  Now the trace buffers are subdivided into several
subbuffers with pagesize.  Therefore it is now possible to allocate more
memory for the trace buffers and more trace records can be written.

In addition to that, dynamic specification of the size of the trace buffers is
implemented.  It is now possible to change the size of a trace buffer using a
new debugfs file instance.  When writing a number into this file, the trace
buffer size is changed to 'number * pagesize'.

In the past all the traces could be obtained from userspace by accessing files
in the "proc" filesystem.  Now with debugfs we have a new filesystem which
should be used for debugging purposes.  This patch moves the debug feature
from procfs to debugfs.

Since the interface of debug_register() changed, all device drivers, which use
the debug feature had to be adjusted.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 4 insertions, 3 deletions

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 3e39508bd929..6527ff6f4706 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -176,7 +176,7 @@ dasd_state_known_to_basic(struct dasd_device * device)
                 return rc;
 
         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
-        device->debug_area = debug_register(device->cdev->dev.bus_id, 0, 2,
+        device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
                                             8 * sizeof (long));
         debug_register_view(device->debug_area, &debug_sprintf_view);
         debug_set_level(device->debug_area, DBF_EMERG);
@@ -1981,7 +1981,7 @@ dasd_init(void)
         init_waitqueue_head(&dasd_init_waitq);
 
         /* register 'common' DASD debug area, used for all DBF_XXX calls */
-        dasd_debug_area = debug_register("dasd", 0, 2, 8 * sizeof (long));
+        dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
         if (dasd_debug_area == NULL) {
                 rc = -ENOMEM;
                 goto failed;
diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c
index d7f19745911f..43c34f8c5e68 100644
--- a/drivers/s390/block/dasd_proc.c
+++ b/drivers/s390/block/dasd_proc.c
@@ -9,13 +9,14 @@
  *
  * /proc interface for the dasd driver.
  *
- * $Revision: 1.31 $
+ * $Revision: 1.32 $
  */
 
 #include <linux/config.h>
 #include <linux/ctype.h>
 #include <linux/seq_file.h>
 #include <linux/vmalloc.h>
+#include <linux/proc_fs.h>
 
 #include <asm/debug.h>
 #include <asm/uaccess.h>