Subject: Re: [PATCH 00/13] Swap-over-NBD without deadlocking

From: Pavel Machek <[email-masked]>
Date: Thu, 28 Apr 2011 15:31:55 +0200

Hi!

> For testing swap-over-NBD, a machine was booted with 2G of RAM with a
> swapfile backed by NBD. 16*NUM_CPU processes were started that create
> anonymous memory mappings and read them linearly in a loop. The total
> size of the mappings were 4*PHYSICAL_MEMORY to use swap heavily under
> memory pressure. Without the patches, the machine locks up within
> minutes and runs to completion with them applied.
> 
> Comments?

Nice!

It  is easy to see why swapping needs these fixes, but... dirty memory
writeout is used for memory clearing, too. Are same changes neccessary
to make that safe?

(Perhaps raise 'max dirty %' for testing?)
								Pavel

-- 
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