# Pagezero using a lot of cpu



## Pushrod (Feb 7, 2009)

A friend of mine is running a distributed computing app, which maxes the CPU and uses around 40MB of ram.

The pagezero kernel process will start to use about 1/4 of the CPU to itself while the app is running. Setting sysctl vm.idlezero_enable=0 makes pagezero calm down.

My question here is, what is the purpose of pagezero (zeroing pages, I know) and is this a performance hit, or is it actually better for this to be happening in a kernel thread?

The machine is a typical home file server which does very little all day, hence the distributed computing app.


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## Pushrod (Feb 8, 2009)

qqq


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