[gentoo-user] where does PID wrap around?

[gentoo-user] where does PID wrap around?

[Iain Buchanan]

Hi all,

I know that PID's wrap around if they get to a sufficiently large number
- anyone know what that number is?

2^16 (65536), or 2^15 (32768)?

Is it fixed for a particular system / kernel / universe? or even better,
is there a #define I can use from one of the system headers?

thanks,
-- 
Iain Buchanan <iaindb at netspace dot net dot au>

The advertisement is the most truthful part of a newspaper.
		-- Thomas Jefferson

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Re: [gentoo-user] where does PID wrap around?

[Zhang Le]

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On 7/27/06, Iain Buchanan <iaindb@netspace.net.au> wrote:
>
> Hi all,
>
> I know that PID's wrap around if they get to a sufficiently large number
> - anyone know what that number is?
>
> 2^16 (65536), or 2^15 (32768)?


$ cat /proc/sys/kernel/pid_max
32768

Is it fixed for a particular system / kernel / universe? or even better,
> is there a #define I can use from one of the system headers?
>
> it is defined in kernel/pid.c
int pid_max = PID_MAX_DEFAULT;

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Re: [gentoo-user] where does PID wrap around?

[Iain Buchanan]

On Thu, 2006-07-27 at 10:20 +0800, Zhang Le wrote:
> On 7/27/06, Iain Buchanan <iaindb@netspace.net.au> wrote:
>         Hi all,
>         
>         I know that PID's wrap around if they get to a sufficiently
>         large number
>         - anyone know what that number is?
>         
>         2^16 (65536), or 2^15 (32768)?
>  
> $ cat /proc/sys/kernel/pid_max
> 32768
> 
>         Is it fixed for a particular system / kernel / universe? or
>         even better,
>         is there a #define I can use from one of the system headers? 
>         
> it is defined in kernel/pid.c
> int pid_max = PID_MAX_DEFAULT;

and PID_MAX_DEFAULT, if you want to #include something, ends up in
<linux/threads.h>

thanks!
-- 
Iain Buchanan <iaindb at netspace dot net dot au>

Never underestimate the bandwidth of a station wagon full of tapes.
		-- Dr. Warren Jackson, Director, UTCS

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Re: [gentoo-user] where does PID wrap around?

[Richard Fish]

On 7/26/06, Iain Buchanan <iaindb@netspace.net.au> wrote:
> and PID_MAX_DEFAULT, if you want to #include something, ends up in
> <linux/threads.h>

You can also use the sysctl() function to get the value at run-time,
just in case it has been changed.  But that will only work on linux.

-Richard
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