Re: [PATCH] CONFIG_NR_CPUS, redux

From: Randy.Dunlap (rddunlap@osdl.org)
Date: Tue Jun 11 2002 - 13:09:35 EST

On 11 Jun 2002, Robert Love wrote:

| Here are the defaults I picked:
|
| CONFIG_NR_CPUS=32: i386, mips, parisc, ppc, sparc

I don't know what is "typical" for non-x86, but for x86, why not
use something more like a 'typical' NR_CPUS for SMP, like 8 (?)...
why still waste all of that memory?

| CONFIG_NR_CPUS=64: alpha, ia64, mips64, ppc64, s390, s390x, sparc64, x86-64
|
| No CONFIG_NR_CPUS: arm, cris, sh
|
| Andrew has pointed out some architectures may need minor tweaks to work
| with NR_CPUS < 32. He discovered and fixed a minor issue on i386...

What was this problem? I missed it but would like to see it.
(or do you know what the Subject: was?)

One spello (typo) below.

| diff -urN linux-2.5.21/arch/i386/Config.help linux/arch/i386/Config.help
| --- linux-2.5.21/arch/i386/Config.help Sat Jun 8 22:27:21 2002
| +++ linux/arch/i386/Config.help Sun Jun 9 13:13:02 2002
| @@ -25,6 +25,14 @@
|
| If you don't know what to do here, say N.
|
| +CONFIG_NR_CPUS
| + This allows you to specify the maximum number of CPUs which this
| + kernel will support. The maximum supported value is 32 and the
| + mimimum value which makes sense is 2.
--- minimum
| +
| + This is purely to save memory - each supported CPU adds
| + approximately eight kilobytes to the kernel image.

Thanks, 

-- 
~Randy

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This archive was generated by hypermail 2b29 : Sat Jun 15 2002 - 22:00:23 EST