Re: Performance problem in aset.c - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Performance problem in aset.c
Date
Msg-id 200007121312.JAA21029@candle.pha.pa.us
Whole thread Raw
In response to Re: Performance problem in aset.c  (Philip Warner <pjw@rhyme.com.au>)
List pgsql-hackers
> At 23:48 11/07/00 -0400, Tom Lane wrote:
> >Another idea is to split the returned chunk and put the wasted part back
> >as a smaller free chunk, but I don't think this solves the problem; it
> >just means that the wasted space ends up on a small-chunk freelist, not
> >that you can actually do anything with it.  But maybe someone can figure
> >out a variant that works better.
> 
> Can you maintain one free list for each power of 2 (which it might already
> be doing by the look of it), and always allocate the max size for the list.
> Then when you want a 10k chunk, you get a 16k chunk, but you know from the
> request size which list to go to, and anything on the list will satisfy the
> requirement.

Sounds like the BSD malloc memory manager.  I can post details, or the
pages from a kernel book I have about it.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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