[PATCH] Rework of /proc/stat

From: Jean-Eric Cuendet (jean-eric.cuendet@linkvest.com)
Date: Wed Mar 06 2002 - 12:16:55 EST


Hi,
I've made a new version of IO statistics in kstat that remove the
previous limitations of MAX_MAJOR
I've made tests on my machine.
Could someone test it, please?
Feedback welcome.
Bye
-jec

--- /tmp/linux-2.4.18-vanilla/include/linux/kernel_stat.h Thu Nov 22 20:46:19 2001
+++ /toc/linux-2.4.18-reempt/include/linux/kernel_stat.h Wed Mar 6 18:02:57 2002
@@ -12,18 +12,37 @@
   * used by rstatd/perfmeter
   */

-#define DK_MAX_MAJOR 16
-#define DK_MAX_DISK 16
+#define DK_MAX_DEVICES 64
+#define DK_BUCKETS 256
+
+
+struct _kstat_block_io
+{
+ struct _kstat_block_io* next;
+
+
unsigned int major;
+ unsigned int minor;
+
+
unsigned int io;
+ unsigned int rio;
+ unsigned int wio;
+ unsigned int rblk;
+ unsigned int wblk;
+};
+typedef struct _kstat_block_io kstat_block_io;
+
+
+/* static array of IO stats */
+extern unsigned int kstat_devices_current_index;
+extern kstat_block_io kstat_devices_array[DK_MAX_DEVICES];
+
+

  struct kernel_stat {
          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];
+ kstat_block_io* io_stat_tbl[DK_BUCKETS];
          unsigned int pgpgin, pgpgout;
          unsigned int pswpin, pswpout;
  #if !defined(CONFIG_ARCH_S390)
@@ -37,6 +56,103 @@

  extern struct kernel_stat kstat;

+
+
+/* Size of the table */
+extern const unsigned int kstat_block_io_tbl_size;
+
+/* hash function */
+static inline unsigned kstat_block_io_hash(unsigned int major, unsigned
int minor)
+{
+ return major * 1999 ^ minor;
+}
+
+
+/* add an IO stat */
+static inline kstat_block_io* kstat_block_io_add(unsigned int major,
unsigned int minor)
+{
+ unsigned int i;
+
kstat_block_io* p;
+ kstat_block_io* pstat;
+
+
if (kstat_devices_current_index >= DK_MAX_DEVICES)
+
{
+
     printk("ERROR: kstat: No more slot for device IO stats. Try
extending DK_MAX_DEVICES\n");
+
     return 0;
+
}
+
+ pstat = &kstat_devices_array[kstat_devices_current_index];
+
kstat_devices_current_index++;
+ pstat->next = 0;
+ pstat->major = major;
+ pstat->minor = minor;
+ pstat->io = 0;
+ pstat->rio = 0;
+ pstat->wio = 0;
+ pstat->rblk = 0;
+ pstat->wblk = 0;
+
+ i = kstat_block_io_hash(major, minor) % kstat_block_io_tbl_size;
+ p = kstat.io_stat_tbl[i];
+
if (p == 0)
+
{
+
     kstat.io_stat_tbl[i] = pstat;
+
}
+
else
+
{
+
     printk("WARNING: kstat: Collision found in IO stat accounting table
(add). Try extending DK_BUCKETS\n");
+ while (p->next != 0)
+
        {
+ p = p->next;
+
        }
+
     p->next = pstat;
+
}
+
return pstat;
+}
+
+/* lookup an IO stat */
+static inline kstat_block_io* kstat_block_io_lookup(unsigned major,
unsigned minor)
+{
+
unsigned int i = kstat_block_io_hash(major, minor) %
kstat_block_io_tbl_size;
+
kstat_block_io* p = kstat.io_stat_tbl[i];
+
while (p && p->major != major && p->minor != minor)
+
{
+
     printk("WARNING: kstat: Collision found in IO stat accounting table
(lookup). Try extending DK_BUCKETS\n");
+
        p = p->next;
+
}
+
if (p == 0)
+
{
+
     p = kstat_block_io_add(major, minor);
+
        if (p == 0)
+
        {
+
            return 0;
+
        }
+
}
+
return p;
+}
+
+/* This is used by MD to see if IDLE */
+static inline unsigned long kstat_get_rwblk(unsigned int major,
unsigned int minor)
+{
+ kstat_block_io* stat = kstat_block_io_lookup(major, minor);
+ if (stat == 0)
+
{
+
     printk("ERROR: kstat: No IO stat found for (%d/%d)\n", major, minor);
+ return 0;
+
}
+ return stat->rblk + stat->wblk;
+}
+
+
+
+
+
+
+
+
+
+
+
  #if !defined(CONFIG_ARCH_S390)
  /*
   * Number of interrupts per specific IRQ source, since bootup
--- /tmp/linux-2.4.18-vanilla/drivers/md/md.c Mon Feb 25 20:37:58 2002
+++ /toc/linux-2.4.18-reempt/drivers/md/md.c Wed Mar 6 16:46:56 2002
@@ -3284,6 +3284,9 @@
          return NULL;
  }

+/* MD devices are major=9 and minor=1-31 */
+#define DK_MAX_MAJOR 16
+#define DK_MAX_DISK 32
  static unsigned int sync_io[DK_MAX_MAJOR][DK_MAX_DISK];
  void md_sync_acct(kdev_t dev, unsigned long nr_sectors)
  {
@@ -3305,15 +3308,12 @@
          unsigned long curr_events;

          idle = 1;
-
ITERATE_RDEV(mddev,rdev,tmp) {
+
ITERATE_RDEV(mddev,rdev,tmp)
+
{
                  int major = MAJOR(rdev->dev);
                  int idx = disk_index(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] ;
+ curr_events = kstat_get_rwblk(major, idx);
                  curr_events -= sync_io[major][idx];
                  if ((curr_events - rdev->last_events) > 32) {
           
        rdev->last_events = curr_events;
--- /tmp/linux-2.4.18-vanilla/drivers/block/ll_rw_blk.c Mon Feb 25 20:37:57 2002
+++ /toc/linux-2.4.18-reempt/drivers/block/ll_rw_blk.c Wed Mar 6 18:12:03 2002
@@ -501,19 +501,22 @@
           
                unsigned long nr_sectors, int new_io)
  {
          unsigned int major = MAJOR(dev);
-
unsigned int index;
+
unsigned int minor = MINOR(dev);
+ kstat_block_io* stat = kstat_block_io_lookup(major, minor);

-
index = disk_index(dev);
-
if ((index >= DK_MAX_DISK) || (major >= DK_MAX_MAJOR))
-
        return;
+ if (stat == 0)
+ {
+
     printk("ERROR: kstat: Haven't found an IO stat struct for major=%d
/ minor=%d\n", major, minor);
+ return;
+
}

-
kstat.dk_drive[major][index] += new_io;
+
stat->io += new_io;
          if (rw == READ) {
-
        kstat.dk_drive_rio[major][index] += new_io;
-
        kstat.dk_drive_rblk[major][index] += nr_sectors;
+
        stat->rio += new_io;
+
        stat->rblk += nr_sectors;
          } else if (rw == WRITE) {
-
        kstat.dk_drive_wio[major][index] += new_io;
-
        kstat.dk_drive_wblk[major][index] += nr_sectors;
+
        stat->wio += new_io;
+
        stat->wblk += nr_sectors;
          } else
                  printk(KERN_ERR "drive_stat_acct: cmd not R/W?\n");
  }
--- /tmp/linux-2.4.18-vanilla/fs/proc/proc_misc.c Wed Nov 21 06:29:09 2001
+++ /toc/linux-2.4.18-reempt/fs/proc/proc_misc.c Wed Mar 6 17:41:28 2002
@@ -282,25 +282,19 @@
                  len += sprintf(page + len, " %u", kstat_irqs(i));
  #endif

-
len += sprintf(page + len, "\ndisk_io: ");
+ 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 (i = 0; i < kstat_devices_current_index; i++)
+ {
+ kstat_block_io* stat = &kstat_devices_array[i];
+ len += sprintf( page + len, "(%u,%u):(%u,%u,%u,%u,%u) ",
+ stat->major, stat->minor,
+ stat->io,
+ stat->rio,
+ stat->wio,
+ stat->rblk,
+ stat->wblk );
+ }

          len += sprintf(page + len,

                  "\nctxt %u\n"

-
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This archive was generated by hypermail 2b29 : Thu Mar 07 2002 - 21:00:55 EST