[xml] 2.5.x performance vs. 2.4.24

[Grant Goodale <grant reactivity com>]

        (I know there's at least one other thread on this, but I joined the
list too late to get in on it.  Sorry.)

        In comparing the aforementioned version of libxml2 (built from tarballs
on the same machine) I ran the following command: 

         xmllint --noout --timing --memory ~/foo.xml

where foo.xml is a well-formed 3.5mb xml file, and got the following
results:

2.4.24: 
Parsing took 327 ms
Freeing took 52 ms

2.5.8:
Parsing took 34013 ms
Freeing took 114 ms

        RH AS2.1, Dual P4 (Seen as 4 procs - yay HT), 2GB memory, kernel
2.4.9-e.25, glibc-2.2.4-32.3.  Anyone seen anything similar on large
documents?  strace shows a large number of calls to brk() taking up most
of the time:

18:55:33.594680 brk(0x8060000)          = 0x8060000
18:55:33.606823 brk(0x8061000)          = 0x8061000
---snip---
18:56:07.875950 brk(0x9209000)          = 0x9209000
18:56:07.876090 brk(0x920a000)          = 0x920a000

        Thanks is advance,

        Grant
        grant reactivity com