Messages in this thread | | | Date | Thu, 8 Aug 2002 22:47:03 +0200 | From | Andries Brouwer <> | Subject | Re: [PATCH] Linux-2.5 fix/improve get_pid() |
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On Thu, Aug 08, 2002 at 12:42:38PM -0700, William Lee Irwin III wrote:
> The goal of the work that produced this was to remove the global > tasklist. Changing ABI's and/or breaking userspace was not "within the > rules" of that.
It feels wrong to add such complexity and simultaneously keep such a small pid_t.
Very soon 30000 processes will not be enough.
Using a 32-bit pid_t does not break userspace. Indeed, user space uses a 32-bit pid_t today. The only complaint I have heard was from Albert Cahalan who maintains ps and was afraid that the ps output would become uglier if pids would get more digits.
It is a real pity that going to a 64-bit pid is impossible (on x64).
Many algorithms can be really efficient if you have a large space to work in. For example, I do not know what your motivation was for wanting to remove the global tasklist. It is certainly needed for sending signals. But if you want to avoid access to global stuff in a MP situation, then it is easy to partition the pid space so that each processor only gives out pids in its own region. (So that simultaneous forks do not interfere.)
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