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

From: John Stoffel
Date: Thu Apr 22 2010 - 14:12:31 EST


>>>>> "Robin" == Robin Holt <holt@xxxxxxx> writes:

>> 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.

Robin> How about:

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

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


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

Looks good, but how about some comments and some defines for the magic
numbers of 2048 and 19?

John

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