[xslt] Dramatically increase of memory operations after upgrade

[Vladimir Grebenschikov <vova sw ru>]

Hi

While upgrade of my product with libxml2 and libxslt

OLD               NEW
libxslt-1.1.11 -> libxslt-1.1.15
libxml2-2.6.14 -> libxml2-2.6.22

After upgrade of XML/XSLT libraries I have notice big slowdown of
parsing XSL documents, trying to resolve issue I've figured out that
problem is due to dramatically increase of number of allocation and
de-allocation during same XSL style-sheet parsing:

test.xsl:
OLD: document test.xsl loading statistics: allocations 33528, de-allocations 14250
NEW: document test.xsl loading statistics: allocations 72089, de-allocations 54475

screen.xsl:
OLD: document screen.xsl loading statistics: allocations 93158, de-allocations 36145
NEW: document screen.xsl loading statistics: allocations 211636, de-allocations 160267

Both documents relatively big with number of includes.
Also I have notice that difference between allocations and de-allocation almost not changed.

~ x 2 times increase for allocations
~ x 4 times increase for de-allocations
~ x 3 times increase in total

It is not clean for me:
- what causes such big increase of number memory allocation operation ?
- why increase of allocations do not consistent with increase of de-allocations ?
- is it desired or it is bug ?

In contrary allocations/de-allocations for loading plain XML documents has a bit lower numbers on new libraries.

Any clues/ideas about it ? 

-- 
Vladimir B. Grebenschikov
SWsoft Inc. vova swsoft com