Re: [Patch 1/1] init: Provide a kernel start parameter to increase pid_max v2

[Robin Holt <holt@sgi.com>]

> Which I'm not entirely sure makes the case for the kernel parameter much 
> stronger, though. I wonder if it's not more appropriate to just have a 
> total hack saying
> 
> 	if (max_pids < N * max_cpus) {
> 		printk("We have %d CPUs, increasing max_pids to %d\n");
> 		max_pids = N*max_cpus;
> 	}
> 
> where "N" is just some random fudge-factor. It's reasonable to expect a 
> certain minimum number of processes per CPU, after all.

How about:

	pid_max_min = max(pid_max_min, 19 * num_possible_cpus());
	pid_max_baseline = 2048 * num_possible_cpus();

	if (pid_max < pid_max_baseline) {
		printk("We have %d CPUs, increasing pid_max to %d\n"...
		pid_max = pid_max_baseline;
	}


This would scale pid_max_min by a sane amount, leave the default value
of pid_max_min and pid_max untouched below 16 cpus and then scale both
up linearly beyond that.

Robin