Re: [9fans] Maximal number of processes

[erik quanstrom <quanstro@quanstro.net>]

> 20,000 did not work because it ran out of kernel physical memory. That
> preallocation could be adjusted, but at some point the available kernel
> virtual address space will limit what it can allocate.

at the cost of moving KZERO down 256MB on the pae kernel,

	ivey# ps|wc
	  15961  111727  957732

and even more

	ivey; ps|wc
	  30064  210448 1803915

	ivey# cat /dev/swap
	17153769472 memory
	4096 pagesize
	131072 kernel
	271322/4056860 user
	0/0 swap
	0/17877472 kernel malloc
	0/17877472 kernel draw

interestingly, the time to launch 1000 sleeps went up in a non-linear way
here's the time to launch each 1000 processes

1000	0
2000	0
3000	1
4000	0
5000	1
6000	0
7000	1
8000	1
9000	0
10000	1
11000	1
12000	1
13000	1
14000	1
15000	2
16000	1
17000	2
18000	2
19000	2
20000	3
21000	3
22000	4
23000	4
24000	5
25000	5
26000	5
27000	7
28000	7
29000	8
30000	8

launching 32000 processes was not possible.  the kernel got stuck.

here's one thing that's not immediately obvious, even when running the
kernel.  conv.nmach must be less than 0x7fffffff/(1000*1000) = 2147
to prevent reprioritize from doing silly things:

	/*
	 *  fairshare = 1.000 * conf.nproc * 1.000/load,
	 * except the decimal point is moved three places
	 * on both load and fairshare.
	 */
	fairshare = (conf.nmach*1000*1000)/load;

- erik