[Vm-dev] Re: [Pharo-project] Waste of CPU Power by polling events?

Levente Uzonyi leves at elte.hu
Tue Jan 11 19:15:42 UTC 2011


On Tue, 11 Jan 2011, Eliot Miranda wrote:

(Pine can't quote your mail, sorry.)

"The problem with linux is that the pthreads implementation doesn't allow 
a normal user-level process to create high-priroity threads so that as
soon as the Vm starts to spin doing some computation the heartbeat thread 
is shut-out and if the spinning computation only interrupted when a delay
expires it'll never get interrupted because it is blocking the very thread 
that would signal the delay.  So until linux's pthreads implementation
supports multiple priorities we're stuck with hacks like the interval 
timer based itimer in the linux Cog VMs."

What about keeping the priority of the heartbeat thread at user-level and 
decreasing the other VM threads' priority slighly?


Levente


More information about the Vm-dev mailing list