Re: [BK] [PATCH] reiserfs changeset 7 of 7 to include into 2.4 tree

Marcelo Tosatti
2002-08-12T19:22:19Z

On Sat, 10 Aug 2002, Hans Reiser wrote:

> I forgot to mention that a variety of benchmarks of various allocator
> options are on www.namesys.com/benchmarks.html. They aren't very
> understandable, but if questions are asked I'll answer them.

I get this from the "Mongo" benchmark homepage.

I suppose the behaviour with your patches is "skip_busy", right?

Block allocator options are passed with alloc=opt1:opt2:... mount
parameter, where opt1, opt2,... are:

skip_busy:
Try to allocate blocks in block-groups (called bitmaps in
reiserfs) that have more than 10% of blocks free first, if that fail,
allocate anywhere.
concentrating_formatted_nodes=X:
turned on 'border algorithm' and put this border in X% of
available space.
old_way:
Mimic original block allocator from 2.4.18
displacing_new_packing_localities:
Displace formatted nodes of directories at creation time.
Displacing is the hash from the dir_id.
displacing_large_files:
Takes one parameter - a blocknumber. When this blocknumber
allocated for the file, it is placed separately on disk (by default new
location is the keyed_hash from the object_id
value. "displace_based_on_dirid" will change that.
displace_based_on_dirid:
When displacing files, place files that live in same directory
in the same disk area. (achieved by hashing by dir_id value of ondisk_key,
instead of object_id)

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