Hi,
sorry for the intrusion. I noticed iostats didn't display statistics for
devices on Mylex RAID constrollers. Det statistics are completely
missing in /proc/stat. The reason seems to be an assumption that disks
have major numbers which are below 16
(http://lxr.linux.no/source/include/linux/kernel_stat.h#L15) which is
used by http://lxr.linux.no/source/fs/proc/proc_misc.c#L344.
Devices on Mylex-controllers have major number 48. Would it break
anything if DK_MAX_MAJOR if set higher (e.g. 64)?
AFAIK this goes for both 2.4 and the 2.5 series.
--
Per Andreas Buer
On Tue, 2002-11-12 at 20:35, Per Andreas Buer wrote:
> Hi,
>
> sorry for the intrusion. I noticed iostats didn't display statistics for
> devices on Mylex RAID constrollers. Det statistics are completely
> missing in /proc/stat. The reason seems to be an assumption that disks
> have major numbers which are below 16
> (http://lxr.linux.no/source/include/linux/kernel_stat.h#L15) which is
> used by http://lxr.linux.no/source/fs/proc/proc_misc.c#L344.
>
> Devices on Mylex-controllers have major number 48. Would it break
> anything if DK_MAX_MAJOR if set higher (e.g. 64)?
>
> AFAIK this goes for both 2.4 and the 2.5 series.
i have been runing with 2.4.x kernel with this number
set higher i have still yet to see any problem with it
other than using more memory.
> On Tue, 2002-11-12 at 20:35, Per Andreas Buer wrote:
> > Hi,
> >
> > sorry for the intrusion. I noticed iostats didn't display statistics for
> > devices on Mylex RAID constrollers. Det statistics are completely
> > missing in /proc/stat. The reason seems to be an assumption that disks
> > have major numbers which are below 16
> > (http://lxr.linux.no/source/include/linux/kernel_stat.h#L15) which is
> > used by http://lxr.linux.no/source/fs/proc/proc_misc.c#L344.
> >
> > Devices on Mylex-controllers have major number 48. Would it break
> > anything if DK_MAX_MAJOR if set higher (e.g. 64)?
> >
> > AFAIK this goes for both 2.4 and the 2.5 series.
>
> i have been runing with 2.4.x kernel with this number
> set higher i have still yet to see any problem with it
> other than using more memory.
>
We've had the same problem, and we've been running with DK_MAX_MAJOR == 64,
using megaraid and acceleraid 2000 controllers.
Haven't seen any problems
cliffw
OSDL
>
> -
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>
sorry for the intrusion. I noticed iostats didn't display statistics for
devices on Mylex RAID constrollers. Det statistics are completely
missing in /proc/stat. The reason seems to be an assumption that disks
have major numbers which are below 16
(http://lxr.linux.no/source/include/linux/kernel_stat.h#L15) which is
used by http://lxr.linux.no/source/fs/proc/proc_misc.c#L344.
Devices on Mylex-controllers have major number 48. Would it break
anything if DK_MAX_MAJOR if set higher (e.g. 64)?
AFAIK this goes for both 2.4 and the 2.5 series.
Which kernel did you observe it on?
In 2.4, yes, you're right. Without patches, there's a limit. Patches do
exist that remove those limits though.
In >= 2.5.47, no. They've been completely removed from /proc/stat and
appear in sysfs. And there are no major device number limits.
For various other flavors of 2.5 and assorted patches, the answer is
"well maybe, kind of" depending on where you got your 2.5 from and
what patches you may have applied on top of that.
Rick
> > > sorry for the intrusion. I noticed iostats didn't display statistics for
> > > devices on Mylex RAID constrollers. Det statistics are completely
> > > missing in /proc/stat. The reason seems to be an assumption that disks
> > > Devices on Mylex-controllers have major number 48. Would it break
> > > anything if DK_MAX_MAJOR if set higher (e.g. 64)?
> > >
> > > AFAIK this goes for both 2.4 and the 2.5 series.
> >
> > i have been runing with 2.4.x kernel with this number
> > set higher i have still yet to see any problem with it
> > other than using more memory.
> >
> We've had the same problem, and we've been running with DK_MAX_MAJOR == 64,
> using megaraid and acceleraid 2000 controllers.
> Haven't seen any problems
> cliffw
> OSDL
i had a patch for a while which solved the problem
though it had problems with scsi stuff and i dont know
if it will even run at all last time i was running it
was on 2.4.17 i think lots of stuff changed and i did not port
it to 2.4.19. Its was not my patch though i picked it off this list
and yet again i cannot remember the original author.
heres what it is but dont hold me to this its not tested on newer
kernels !!.
James
Index: drivers/block/ll_rw_blk.c
===================================================================
RCS file: /cvs-root/kernel-source/drivers/block/ll_rw_blk.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 ll_rw_blk.c
--- drivers/block/ll_rw_blk.c 30 Dec 2001 08:47:06 -0000 1.1.1.1
+++ drivers/block/ll_rw_blk.c 13 Jan 2002 15:33:30 -0000
@@ -183,7 +183,11 @@
if (count)
printk("blk_cleanup_queue: leaked requests (%d)\n", count);
-
+ /*
+ * free statistics structure
+ */
+ kfree(q->dk_stat);
+
memset(q, 0, sizeof(*q));
}
@@ -393,6 +397,8 @@
**/
void blk_init_queue(request_queue_t * q, request_fn_proc * rfn)
{
+ struct disk_stat * new;
+
INIT_LIST_HEAD(&q->queue_head);
elevator_init(&q->elevator, ELEVATOR_LINUS);
blk_init_free_list(q);
@@ -413,6 +419,15 @@
*/
q->plug_device_fn = generic_plug_device;
q->head_active = 1;
+ /*
+ * At last, allocate and initialize the statistics
+ */
+ new = kmalloc(sizeof(struct disk_stat), GFP_KERNEL);
+ if (new == NULL)
+ printk(KERN_ERR "blk_init_queue:error allocating statisitcs\n");
+ else
+ memset(new, 0, sizeof(struct disk_stat));
+ q->dk_stat = new;
}
#define blkdev_free_rq(list) list_entry((list)->next, struct request, queue);
@@ -497,23 +512,18 @@
else ro_bits[major][minor >> 5] &= ~(1 << (minor & 31));
}
-inline void drive_stat_acct (kdev_t dev, int rw,
+inline void drive_stat_acct (struct disk_stat * ds, int rw,
unsigned long nr_sectors, int new_io)
{
- unsigned int major = MAJOR(dev);
- unsigned int index;
-
- index = disk_index(dev);
- if ((index >= DK_MAX_DISK) || (major >= DK_MAX_MAJOR))
+ if (ds == NULL)
return;
- kstat.dk_drive[major][index] += new_io;
if (rw == READ) {
- kstat.dk_drive_rio[major][index] += new_io;
- kstat.dk_drive_rblk[major][index] += nr_sectors;
+ ds->dk_drive_rio += new_io;
+ ds->dk_drive_rblk += nr_sectors;
} else if (rw == WRITE) {
- kstat.dk_drive_wio[major][index] += new_io;
- kstat.dk_drive_wblk[major][index] += nr_sectors;
+ ds->dk_drive_wio += new_io;
+ ds->dk_drive_wblk += nr_sectors;
} else
printk(KERN_ERR "drive_stat_acct: cmd not R/W?\n");
}
@@ -529,7 +539,7 @@
static inline void add_request(request_queue_t * q, struct request * req,
struct list_head *insert_here)
{
- drive_stat_acct(req->rq_dev, req->cmd, req->nr_sectors, 1);
+ drive_stat_acct(q->dk_stat, req->cmd, req->nr_sectors, 1);
if (!q->plugged && q->head_active && insert_here == &q->queue_head) {
spin_unlock_irq(&io_request_lock);
@@ -701,7 +711,7 @@
req->bhtail = bh;
req->nr_sectors = req->hard_nr_sectors += count;
blk_started_io(count);
- drive_stat_acct(req->rq_dev, req->cmd, count, 0);
+ drive_stat_acct(q->dk_stat, req->cmd, count, 0);
attempt_back_merge(q, req, max_sectors, max_segments);
goto out;
@@ -716,7 +726,7 @@
req->sector = req->hard_sector = sector;
req->nr_sectors = req->hard_nr_sectors += count;
blk_started_io(count);
- drive_stat_acct(req->rq_dev, req->cmd, count, 0);
+ drive_stat_acct(q->dk_stat, req->cmd, count, 0);
attempt_front_merge(q, head, req, max_sectors, max_segments);
goto out;
Index: drivers/ide/ide.c
===================================================================
RCS file: /cvs-root/kernel-source/drivers/ide/ide.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 ide.c
--- drivers/ide/ide.c 30 Dec 2001 08:47:37 -0000 1.1.1.1
+++ drivers/ide/ide.c 13 Jan 2002 15:33:31 -0000
@@ -1451,8 +1451,10 @@
request_queue_t *ide_get_queue (kdev_t dev)
{
ide_hwif_t *hwif = (ide_hwif_t *)blk_dev[MAJOR(dev)].data;
-
- return &hwif->drives[DEVICE_NR(dev) & 1].queue;
+ if (DEVICE_NR(dev) >= MAX_DRIVES)
+ return NULL;
+ else
+ return &hwif->drives[DEVICE_NR(dev)].queue;
}
/*
Index: drivers/md/md.c
===================================================================
RCS file: /cvs-root/kernel-source/drivers/md/md.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 md.c
--- drivers/md/md.c 30 Dec 2001 08:47:51 -0000 1.1.1.1
+++ drivers/md/md.c 13 Jan 2002 15:33:32 -0000
@@ -3302,12 +3302,15 @@
ITERATE_RDEV(mddev,rdev,tmp) {
int major = MAJOR(rdev->dev);
int idx = disk_index(rdev->dev);
-
+ request_queue_t * rq = blk_get_queue(rdev->dev);
+
if ((idx >= DK_MAX_DISK) || (major >= DK_MAX_MAJOR))
continue;
-
- curr_events = kstat.dk_drive_rblk[major][idx] +
- kstat.dk_drive_wblk[major][idx] ;
+
+ if (rq == NULL || (rq->dk_stat == NULL))
+ continue;
+ curr_events = rq->dk_stat->dk_drive_rblk +
+ rq->dk_stat->dk_drive_wblk ;
curr_events -= sync_io[major][idx];
if ((curr_events - rdev->last_events) > 32) {
rdev->last_events = curr_events;
Index: fs/proc/proc_misc.c
===================================================================
RCS file: /cvs-root/kernel-source/fs/proc/proc_misc.c,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 proc_misc.c
--- fs/proc/proc_misc.c 30 Dec 2001 08:44:42 -0000 1.1.1.1
+++ fs/proc/proc_misc.c 13 Jan 2002 15:33:35 -0000
@@ -36,12 +36,12 @@
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/seq_file.h>
+#include <linux/blkdev.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/io.h>
-
#define LOAD_INT(x) ((x) >> FSHIFT)
#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
/*
@@ -234,7 +234,23 @@
release: seq_release,
};
#endif
-
+static int show_disk_stat(char * page, int len, struct disk_stat * ds,
+ int major, int disk)
+{
+ int active = ds->dk_drive_rio + ds->dk_drive_wio +
+ ds->dk_drive_rblk + ds->dk_drive_wblk;
+ if (active)
+ len += sprintf(page + len,
+ "(%u,%u):(%u,%u,%u,%u,%u) ",
+ major, disk,
+ ds->dk_drive_rio + ds->dk_drive_wio,
+ ds->dk_drive_rio,
+ ds->dk_drive_rblk,
+ ds->dk_drive_wio,
+ ds->dk_drive_wblk
+ );
+ return len;
+}
static int kstat_read_proc(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
@@ -284,21 +300,27 @@
len += sprintf(page + len, "\ndisk_io: ");
- for (major = 0; major < DK_MAX_MAJOR; major++) {
- for (disk = 0; disk < DK_MAX_DISK; disk++) {
- int active = kstat.dk_drive[major][disk] +
- kstat.dk_drive_rblk[major][disk] +
- kstat.dk_drive_wblk[major][disk];
- if (active)
- len += sprintf(page + len,
- "(%u,%u):(%u,%u,%u,%u,%u) ",
- major, disk,
- kstat.dk_drive[major][disk],
- kstat.dk_drive_rio[major][disk],
- kstat.dk_drive_rblk[major][disk],
- kstat.dk_drive_wio[major][disk],
- kstat.dk_drive_wblk[major][disk]
- );
+ for (major = 0; major < MAX_BLKDEV; major++) {
+ struct disk_stat * ds;
+
+ if (!(blk_dev[major].queue)){
+ ds = (BLK_DEFAULT_QUEUE(major))->dk_stat;
+ if (ds)
+ len = show_disk_stat(page, len, ds, major, 0);
+ }else {
+ request_queue_t * q;
+ struct gendisk * hd = get_gendisk(MKDEV(major,0));
+ int max_disk = MINORMASK>>hd->minor_shift;
+
+ for (disk = 0; disk <= max_disk; disk++) {
+ q = blk_get_queue(MKDEV(major,disk<<hd->minor_shift));
+ if (!q)
+ continue;
+ ds = q->dk_stat;
+ if (!ds)
+ continue;
+ len = show_disk_stat(page, len, ds, major,disk);
+ }
}
}
Index: include/linux/blkdev.h
===================================================================
RCS file: /cvs-root/kernel-source/include/linux/blkdev.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 blkdev.h
--- include/linux/blkdev.h 30 Dec 2001 08:45:13 -0000 1.1.1.1
+++ include/linux/blkdev.h 13 Jan 2002 15:33:37 -0000
@@ -71,6 +71,13 @@
struct list_head free;
};
+struct disk_stat{
+ unsigned int dk_drive_rio;
+ unsigned int dk_drive_wio;
+ unsigned int dk_drive_rblk;
+ unsigned int dk_drive_wblk;
+};
+
struct request_queue
{
/*
@@ -122,6 +129,10 @@
* Tasks wait here for free request
*/
wait_queue_head_t wait_for_request;
+ /*
+ * statistics
+ */
+ struct disk_stat * dk_stat;
};
struct blk_dev_struct {
@@ -186,7 +197,7 @@
#define blkdev_next_request(req) blkdev_entry_to_request((req)->queue.next)
#define blkdev_prev_request(req) blkdev_entry_to_request((req)->queue.prev)
-extern void drive_stat_acct (kdev_t dev, int rw,
+extern void drive_stat_acct (struct disk_stat *, int rw,
unsigned long nr_sectors, int new_io);
static inline int get_hardsect_size(kdev_t dev)
Index: include/linux/kernel_stat.h
===================================================================
RCS file: /cvs-root/kernel-source/include/linux/kernel_stat.h,v
retrieving revision 1.1.1.1
diff -u -r1.1.1.1 kernel_stat.h
--- include/linux/kernel_stat.h 30 Dec 2001 08:45:14 -0000 1.1.1.1
+++ include/linux/kernel_stat.h 13 Jan 2002 15:33:37 -0000
@@ -19,11 +19,6 @@
unsigned int per_cpu_user[NR_CPUS],
per_cpu_nice[NR_CPUS],
per_cpu_system[NR_CPUS];
- unsigned int dk_drive[DK_MAX_MAJOR][DK_MAX_DISK];
- unsigned int dk_drive_rio[DK_MAX_MAJOR][DK_MAX_DISK];
- unsigned int dk_drive_wio[DK_MAX_MAJOR][DK_MAX_DISK];
- unsigned int dk_drive_rblk[DK_MAX_MAJOR][DK_MAX_DISK];
- unsigned int dk_drive_wblk[DK_MAX_MAJOR][DK_MAX_DISK];
unsigned int pgpgin, pgpgout;
unsigned int pswpin, pswpout;
#if !defined(CONFIG_ARCH_S390)