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Hi .misc,

I've written a piece of code based on the examples of the man pages of
sysctl().

After some modifications and compiling, I executed the binary and got:
0.00000
Which wasn't the kind of load average I was looking for..

Does anybody know where I'm going wrong here?

The code ->

[teksec:~/C]$ cat data.c
#include <sys/param.h>
#include <sys/sysctl.h>
#include <uvm/uvm_param.h>

int main()
{

int mib[2];
struct loadavg load;
size_t len;
len = sizeof(load);
mib[0] = CTL_VM;
mib[1] = VM_LOADAVG;

sysctl(mib,2,&load, &len, NULL, 0);

printf("%f\n",load.ldavg[0]);

}
[teksec:~/C]$

<- edoc ehT

If somebody could help me out with this one...

Thanks!

Sacha

PS: struct loadavg... load.ldavg is of some wicked filetype. I don't
think this goes well with the given printf() parameters.

On Fri, 17 Oct 2003, S.Ligthert wrote:

> After some modifications and compiling, I executed the binary and got:
> 0.00000
> Which wasn't the kind of load average I was looking for..

> printf("%f\n",load.ldavg[0]);

ldavg is fixed point (integer), not floating point. divide by the scale.

you want printf("%f\n", (float)load.ldavg[0] / load.fscale);

> PS: struct loadavg... load.ldavg is of some wicked filetype. I don't
> think this goes well with the given printf() parameters.

well, kinda. fixpt_t is really uint32_t and works fine with %d, but you
probably want to scale and print as a float.


--
"First, it was not a strip bar, it was an erotic club. And second,
what can I say? I'm a night owl."
- M. Barry, Mayor of Washington, DC

Hi Ted,


>>printf("%f\n",load.ldavg[0]);
>
>
> ldavg is fixed point (integer), not floating point. divide by the scale.
>
> you want printf("%f\n", (float)load.ldavg[0] / load.fscale);

Thanks! I would never have thought of that..
(thanking my inferior C knowledge)

>>PS: struct loadavg... load.ldavg is of some wicked filetype. I don't
>>think this goes well with the given printf() parameters.
>
>
> well, kinda. fixpt_t is really uint32_t and works fine with %d, but you
> probably want to scale and print as a float.

Do you have any RTFM/pointer/hints/etc concerning these kind of file
types and how to handle them?
(So I won't have to bother comp.unix.bsd.openbsd.misc with it again )

I have to confess this is the first time I have even coded this "deep"
with systemfunctions. But .c .h and man files are a great help

Sacha

On Sat, 18 Oct 2003, S.Ligthert wrote:

> > well, kinda. fixpt_t is really uint32_t and works fine with %d, but you
> > probably want to scale and print as a float.
>
> Do you have any RTFM/pointer/hints/etc concerning these kind of file
> types and how to handle them?

look at the sources to a program like w that does the same thing.
or grep for fixpt_t in sys/sys/*.h and find the typedef.


--
"What right does Congress have to go around making laws just
because they deem it necessary?"
- M. Barry, Mayor of Washington, DC

> look at the sources to a program like w that does the same thing.
> or grep for fixpt_t in sys/sys/*.h and find the typedef.

These kind if tools help me a lott atm. But I'm still stuck at with the
following piece of code :s

The code of top.c is very helpfull, with machine.c at the front of it all!

----> code

#include <stdlib.h>
#include <stdio.h>
#include <sys/param.h>
#include <sys/sysctl.h>
#include <uvm/uvm_param.h>

int main()
{

int mib[2];
size_t length;
struct vmtotal memstats;

mib[0] = CTL_VM;
mib[1] = VM_METER;

length = sizeof(memstats);

sysctl( mib, 2, &memstats, &length, NULL, 0);

/* All the folowing memstats.* types are: u_int32_t */
/* Struct info: vmmeter.h: line 44 of 99 [44%] */
printf("Total Virtual Memory: %d\n",memstats.t_vm);
printf("Active Virtual Memory: %d\n",memstats.t_avm);
printf("Total Real Memory in use: %d\n",memstats.t_rm);
printf("Active Real Memory: %d\n",memstats.t_arm);
printf("Shared Real Memory: %d\n",memstats.t_vmshr);
printf("Active Shared Virtual Memory: %d\n",memstats.t_avmshr);
printf("Shared Real Memory: %d\n",memstats.t_rmshr);
printf("Active Shared Real Memory %d\n",memstats.t_armshr);

}

edoc <----

It gives the weirdest outputs (that obviously need / 1024. But doesn't
help alot :-s ).
I think I have to convert it from "pages" with a size of "4096" to
Kilobytes. After some googling Cygwin site told me that u_int32_t the
same is as unsigned int (which doesn't show up at sys/sys/*.h).

Thanx so far! :-)

Sacha

PS: Sorry for bugging you with this :-\ This little student really
under-estimated his C-skills. But after this is fixed, I think I got the
hardest part behind me then.

Hi .misc

Ted Unangst wrote:
> look at the sources to a program like w that does the same thing.
> or grep for fixpt_t in sys/sys/*.h and find the typedef.

These kind if tools help me a lott atm. But I'm still stuck at with the
following piece of code :s

The code of top.c is very helpfull, with machine.c at the front of it all!

----> code

#include <stdlib.h>
#include <stdio.h>
#include <sys/param.h>
#include <sys/sysctl.h>
#include <uvm/uvm_param.h>

int main()
{

int mib[2];
size_t length;
struct vmtotal memstats;

mib[0] = CTL_VM;
mib[1] = VM_METER;

length = sizeof(memstats);

sysctl( mib, 2, &memstats, &length, NULL, 0);

/* All the folowing memstats.* types are: u_int32_t */
/* Struct info: vmmeter.h: line 44 of 99 [44%] */
printf("Total Virtual Memory: %d\n",memstats.t_vm);
printf("Active Virtual Memory: %d\n",memstats.t_avm);
printf("Total Real Memory in use: %d\n",memstats.t_rm);
printf("Active Real Memory: %d\n",memstats.t_arm);
printf("Shared Real Memory: %d\n",memstats.t_vmshr);
printf("Active Shared Virtual Memory: %d\n",memstats.t_avmshr);
printf("Shared Real Memory: %d\n",memstats.t_rmshr);
printf("Active Shared Real Memory %d\n",memstats.t_armshr);

}

edoc <----

It gives the weirdest outputs (that obviously need / 1024. But doesn't
help alot :-s ).
I think I have to convert it from "pages" with a size of "4096" to
Kilobytes. After some googling Cygwin site told me that u_int32_t the
same is as unsigned int (which doesn't show up at sys/sys/*.h).

Thanx so far!

Sacha

PS: Sorry for bugging you with this This little student really
under-estimated his C-skills. But after this is fixed, I think I got the
hardest part behind me then.

On Sun, 19 Oct 2003, S.Ligthert wrote:

> It gives the weirdest outputs (that obviously need / 1024. But doesn't
> help alot :-s ).
> I think I have to convert it from "pages" with a size of "4096" to
> Kilobytes. After some googling Cygwin site told me that u_int32_t the
> same is as unsigned int (which doesn't show up at sys/sys/*.h).

not sure what the question is, but many vm stats are kept in pages. so to
get k, have to multiply by (pagesize / 1024).
u_int32_t may be defined in arch/*/include/*.h, there's many more typedefs
and defines hiding in there.

--
"I am making this trip to Africa because Washington is an international
city, just like Tokyo, Nigeria or Israel. As mayor, I am an
international symbol. Can you deny that to Africa?"
- M. Barry, Mayor of Washington, DC

Hi Ted + .misc

> not sure what the question is, but many vm stats are kept in pages. so to
> get k, have to multiply by (pagesize / 1024).
> u_int32_t may be defined in arch/*/include/*.h, there's many more typedefs
> and defines hiding in there.

The issue is now resolved. The figures I got was the memory size in
pages of 4096 bits. Instead of /1024 or /4096 the lott I had to do *4096
to get the memory size in bits. Twice /1024 to get the size in Megabytes
(bc(1) is my friend)

It took me a g'ddamn weekend, but hey! A wise lesson learned today

Thanks for your feedback

Sacha