Re: Todays Kernel Release - 2.0.37pre3

[Stephen Rothwell]

> From: Pete Harlan <[e-mail]>
> Date: 	Wed, 16 Dec 1998 11:02:44 +1100
> 
> Did something change recently that prevents increasing NR_TASKS (to
> 4096)?  (I am remembering to do a make clean before recompiling.)
> 
> I did this happily with 35presomethings, but get reboots during
> "Loading Linux Kernel" with .36 and .37pre{2,3}.  (Whether LILO or
> zImage-on-a-floppy.)
> 
> ASUS P2L97 w/built-in Adaptec SCSI.  Bare-bones kernel: No ide.  No
> serial.  No modules.  No cdrom.  192mb ecc sdram.  GCC 2.7.2.1.
> zImage ~370kb.

You should never have got a working kernel with more NR_TASKS set to
more than 4092 (4090 with APM enabled).  Do you use APM?

You are constrained by the fact that we use two entries in the GDT
(Global Descriptor Table) for each process.  There are at most
8192 entries in the GDT and the kernel uses the first 8 for
itself.  In the 2.0 kernel, APM uses three more descriptors
at the end of the table.  In the 2.1 kernels, APM uses four
more at the beginning.

Cheers,
Stephen Rothwell		[e-mail]