Re: [PATCH] write-tree performance problems

From: C. Scott Ananian <cscott@cscott.net>
Date: Apr 20, 2005, 15:52 UTC
Message-ID: <Pine.LNX.4.61.0504201147280.2630@cag.csail.mit.edu>
In-Reply-To: <Pine.LNX.4.58.0504200840240.6467@ppc970.osdl.org>

On Wed, 20 Apr 2005, Linus Torvalds wrote:

Show 6 quoted lines

>> I was considering using a chunked representation for *all* files (not just
>> blobs), which would avoid the original 'trees must reference other trees
>> or they become too large' issue -- and maybe the performance issue you're
>> referring to, as well?
> No. The most common index file operation is reading, and that's the one
> that has to be _fast_. And it is - it's a single "mmap" and some parsing.

OK, sure. But how 'bout chunking trees? Are you grown happy with the new trees-reference-other-trees paradigm, or is there a deep longing in your heart for the simplicity of 'trees-reference-blobs-period'? I'm fairly certain that chunking could get you the space-savings you need without multi-level trees, if the simplicity of that is still appealing.

Not necessarily for rev.1 of the chunking code, but I'm curious as to 
whether it's still of interest at all.  I don't know exactly how far
ingrained multilevel trees have become since they were adopted.
  --scott

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