Subject: Re: Heads up, kernel changes
To: Adam Hamsik <>
From: Andrew Doran <>
List: current-users
Date: 07/11/2007 10:28:25
Hi Adam,

On Wed, Jul 11, 2007 at 09:45:55AM +0200, Adam Hamsik wrote:

> I'm curious about how your changes (merged and unmerged vmlocking  
> branch) impact performance on SMP machines.
> I think that these changes are mostly positive :), but I'm not sure.

Merged: select/poll are slightly more efficient, system V semaphores
do not require the kernel lock (although I need to switch that on).

Eventually: the VM system, ffs and tmpfs file systems, pipes, and a good
chunk of other stuff will run without the kernel lock. Theoretically it will
improve performance for a number of tasks on MP systems but the proof will
be in the numbers.