Re: sysctl add macros

Venkata Duvvuru wrote this message on Mon, Dec 02, 2013 at 07:10 +0000:
> I could use an int variable but if I have to dump huge number of statistics through sysctl in which case I need to add many such variables to the nodes and even if most of these variables are char I have to declare them as int, hence resulting in an increased footprint.

If it's a few 10s of vars, then it isn't a big deal, but if it is 1000's,
then you might want to look at another method to extract the data since
the overhead of sysctl is expensive...  Something like writing a _PROC
routine that will copy them all out in a single sysctl call..

> -----Original Message-----
> From: John-Mark Gurney [mailto:jmg_at_funkthat.com] 
> Sent: Sunday, December 01, 2013 3:00 AM
> To: Venkata Duvvuru
> Cc: Matthew Fleming; freebsd-current_at_freebsd.org
> Subject: Re: sysctl add macros
> 
> Venkata Duvvuru wrote this message on Mon, Nov 25, 2013 at 14:58 +0000:
> > The problem with using int or u_int for 1 or 2 byte values is that while printing these 1 or 2 byte values I observed that sysctl module is considering 4 bytes. Hence I see an undesired output. It is actually considering the next two bytes also as the value.
> 
> If you _NEED_ to use a char or short, you need to write your own/clone it from the macros...
> 
> Why can't you use an int for this variable?
> 
> > From: mdf356_at_gmail.com [mailto:mdf356_at_gmail.com] On Behalf Of Matthew 
> > Fleming
> > Sent: Monday, November 25, 2013 8:18 PM
> > To: Venkata Duvvuru
> > Cc: freebsd-current_at_freebsd.org
> > Subject: Re: sysctl add macros
> > 
> > On Mon, Nov 25, 2013 at 3:35 AM, Venkata Duvvuru <VenkatKumar.Duvvuru_at_emulex.com<mailto:VenkatKumar.Duvvuru_at_emulex.com>> wrote:
> > Hi,
> > I'm unable to figure out how to add an unsigned short or an unsigned char values to a sysctl node.
> > SYSCTL_ADD_INT, SYSCTL_ADD_UINT, etc., are present but to add a char or a short values I couldn't find any macros.
> > 
> > Could you please let me know how to add them?
> > 
> > FreeBSD does not have any sysctl handlers for 1 or 2 byte values.  FreeBSD code that wants to do this has used int or u_int instead of a smaller type.
> 
> -- 
>   John-Mark Gurney				Voice: +1 415 225 5579
> 
>      "All that I will do, has been done, All that I have, has not."
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-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."