Re: Multi Core Support for compression in compression.c

From: Austin S Hemmelgarn
Date: Sun Jul 27 2014 - 22:56:27 EST

On 07/27/2014 04:47 PM, Nick Krause wrote:
> This may be a bad idea , but compression in brtfs seems to be only
> using one core to compress.
> Depending on the CPU used and the amount of cores in the CPU we can
> make this much faster
> with multiple cores. This seems bad by my reading at least I would
> recommend for writing compression
> we write a function to use a certain amount of cores based on the load
> of the system's CPU not using
> more then 75% of the system's CPU resources as my system when idle has
> never needed more
> then one core of my i5 2500k to run when with interrupts for opening
> eclipse are running. For reading
> compression on good core seems fine to me as testing other compression
> software for reads , it's
> way less CPU intensive.
> Cheers Nick
We would probably get a bigger benefit from taking an approach like
SquashFS has recently added, that is, allowing multi-threaded
decompression fro reads, and decompressing directly into the pagecache.
Such an approach would likely make zlib compression much more scalable
on large systems.

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