David Laight wrote in
 <[email protected]>:
 |From: Steffen Nurpmeso
 |> Sent: 01 March 2022 17:49
 |> David Laight wrote in
 |>  <[email protected]>:
 |>|From: Denys Vlasenko
 |>|> Sent: 01 March 2022 16:40
 |>|> On Tue, Feb 15, 2022 at 12:31 PM Rob Landley <[email protected]> wrote:
 |>|>> On 2/14/22 10:09 AM, Roberto A. Foglietta wrote:
 |>  ...
 |>|> My memory is hazy on this, but IIRC kernel also actually has some
 |>|> defensive code to not immediately reuse pids which just died.
 |>|
 |>|The Linux krnel only has protection for code inside the kernel.
 |>|Basically there is a ref-counted structure that you need to send the
 |>|signal - not the pid itself.
 |>|I can't quite remember whether the pid itself can be reused even before
 |>|that structure is freed.
 |>|
 |>|NetBSD does guarantee not to reuse a pid for a reasonable number
 |>|of forks after a process exits.
 |> 
 |> ...which might be fruitless with 16-bit pids, define "reasonable".
 |
 |Nothing stops pids going beyond 16 bits.
 |(Apart from some of the very old emulations.)
 |Much like nothing really requires the pid allocator to even start
 |allocating linearly (after giving init pid 1) - but that is
 |rather expected.
 |
 |I can't remember at which point it went above 32767.
 |Was over 20 years ago when I wrote it :-)

Ah, kernel.  Not my league then :-)

(I knew the (Linux) sysctl/proc entry, but it is unchanged here.)

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)
_______________________________________________
busybox mailing list
[email protected]
http://lists.busybox.net/mailman/listinfo/busybox

Reply via email to