Subject: Re: Speeding up fork/wait path
To: Jaromir Dolecek <>
From: Jason Thorpe <>
List: tech-kern
Date: 11/02/2003 11:50:50
On Sunday, November 2, 2003, at 11:06  AM, Jaromir Dolecek wrote:

> I implemented similar solution.
> Exiting process now:
> 1. pmap_deactivate()s the address space and frees the vmspace
> 2. runs cpu_wait() (tears down TSS on i386 & amd64)
> 3. makes the process SZOMB
> 4. keeps KERNEL_PROC_LOCK()

This is pretty cool.


	* Rename cpu_wait() to cpu_exit().

	* Also drain u-areas when allocating VM from kernel_map
	  fails (then retry).

Have you done the fork/exit benchmark before and after this change?  I 
would also do a 4-job build of the source tree with this change to 
heavily exercise the fork/exit/wait code path.

         -- Jason R. Thorpe <>