Re: Since no one else has stepped forward: 'ZeroD' patch
Andi Kleen (andi@mlm.extern.lrz-muenchen.de)
Wed, 08 Jan 1997 19:12:35 +0100
In message <m0vi2Ft-0007krC@dingo.theplanet.co.uk>you write:
>} Ingo Molnar <mingo@pc5829.hil.siemens.at> writes:
>}
>} > Here is a patch that implements 'ZeroD', a simple kernel thread that uses
>} > up CPU idle time to keep a pool of pre-zeroed pages around. Almost
>} > anything that doesnt burn 100% CPU time all the time should benefit from
>} > this.
>}
>} Hmm, did you check that this hasn't a bad effect on the cache memory when
>} a cpu intensive process has to sleep for short times?
>} A /proc/sys interface to tune it would be nice too.
>
>This would also presumably affect the heat production of the CPU -
>especially on hot Cyrixs!
>
>Does it spend all the idle time doing this, or just a part??
Just a part, until its zero-page-pool is full. The patch uses
a size of 50 pages. Bad interactions with the 1nd./2nd. level
cache could still happen though (on the Alpha and on the Sparc
platform too). We would at least need some benchmarks to check
that it is worth the effort.
-Andi