Conference turris::digital_unix

8787.0. "where is now the VM_PAGE_WIRE_COUNT" by NETRIX::"[email protected]" ([email protected]) Tue Feb 11 1997 08:52

Hello,

A customer had a program running in DEC OSF/1 V2.1 to read some kernel values.
In Digital UNIX V3.2G it works except for the value of VM_PAGE_WIRE_COUNT.

I know this value could be read from table(), but customer ask if it could be
still read from /dev/kmem. 

Thanks in avance,

Jose Ignacio Lopez

(Sample Code is below)
#include <stdio.h>
#include <fcntl.h>
#include <nlist.h>
#include <sys/dk.h>

#include "cpumem.h"

#define CP_TIME                         0
#define VM_PAGE_FREE_COUNT              1
#define VM_PAGE_ACTIVE_COUNT            2
#define VM_PAGE_INACTIVE_COUNT          3
#define UBC_LRU_PAGE_COUNT              4
#define VM_PAGE_WIRE_COUNT              5    /* This doesn't work in V3.2G */
#define VM_PAGE_SWAP_SPACE              6
#define VM_TOTAL_PAGE_SWAP_SPACE        7

struct nlist nl[]=
{
  { "cp_time" },
  { "vm_page_free_count" },
  { "vm_page_active_count" },
  { "vm_page_inactive_count" },
  { "ubc_lru_page_count" },
  { "vm_page_wire_count" },
  { "vm_swap_space" },
  { "vm_total_swap_space" },
  { NULL }
};

static int  kmem_fd;
static long oldloadcpu[CPUSTATES] = {0,0,0,0,0};

extern cpumem_kernel_init ()
{
  nlist ("/vmunix", nl);
  kmem_fd = open ("/dev/kmem", O_RDONLY);
}

extern int cpumem_kernel_read (int *cpuloadp, int *memloadp,
                               int *swaploadp)
{
  int     freememory;
  int     activememory, actmemory, inactmemory, ubclrumemory;
  int     wirememory,carga_cpu;
  long    freeswap, totalswap;
  long    loadcpu[CPUSTATES], cputotal;
  int     i,j;

  lseek (kmem_fd, nl[CP_TIME].n_value, SEEK_SET);
  read (kmem_fd, &carga_cpu, sizeof (carga_cpu));
  lseek (kmem_fd, nl[VM_PAGE_FREE_COUNT].n_value, SEEK_SET);
  read (kmem_fd, &freememory, sizeof (freememory));
  lseek (kmem_fd, nl[VM_PAGE_ACTIVE_COUNT].n_value, SEEK_SET);
  read (kmem_fd, &actmemory, sizeof (actmemory));
  lseek (kmem_fd, nl[VM_PAGE_INACTIVE_COUNT].n_value, SEEK_SET);
  read (kmem_fd, &inactmemory, sizeof (inactmemory));
  lseek (kmem_fd, nl[UBC_LRU_PAGE_COUNT].n_value, SEEK_SET);
  read (kmem_fd, &ubclrumemory, sizeof (ubclrumemory));
  lseek (kmem_fd, nl[VM_PAGE_WIRE_COUNT].n_value, SEEK_SET);
  read (kmem_fd, &wirememory, sizeof (wirememory));
  lseek (kmem_fd, nl[VM_PAGE_SWAP_SPACE].n_value, SEEK_SET);
  read (kmem_fd, &freeswap, sizeof (freeswap));
  lseek (kmem_fd, nl[VM_TOTAL_PAGE_SWAP_SPACE].n_value, SEEK_SET);
  read (kmem_fd, &totalswap, sizeof (totalswap));

printf("carga_cpu= %d\n", carga_cpu);
printf("freeswap= %d\n",freeswap);
printf("totalswap= %d\n",totalswap);

printf("freememory= %d\n",freememory);
printf("actmemory= %d\n",actmemory);
printf("inactmemory= %d\n",inactmemory);
printf("ubclrumemory= %d\n",ubclrumemory);
printf("wirememory= %d\n",wirememory);
/* This gives a completly wrong value ****************/


/* printf("totalswap= %d\n",totalswap);
*/
  activememory = actmemory + inactmemory + ubclrumemory;

printf("activememory= %d\n",activememory);


  *memloadp = (int) ((wirememory + activememory) * 100L /
                     (freememory + activememory + wirememory));

printf("memloadp= %d\n",*memloadp);
 

[Posted by WWW Notes gateway]

The wired page statistics are now kept in the vm_perf structure
(it is defined in /sys/include/vm/vm_perf.h, not an exported user
include file).

table(TBL_VMSTATS) is the preferred method.  Besides being faster,
it isolates the user from kernel data structure changes.

--shashi
[Posted by WWW Notes gateway]