performance of parsing docbook with xincludes
Stefan Sauer <[email protected]>
| Newsgroups | gmane.comp.gnome.lib.xml.general |
|---|---|
| Message-ID | <[email protected]> |
hi, I am the maintainer of gtk-doc. One biggest complaint I get is the performance. gtk-doc is scanning sources and combining the extracted comments with handwritten docbook into a signle docbook document. The docbook document uses xinclude for its parts. As a next step we were using the docbook-stylesheets to generate reference docs as html (and dblatex for pdfs). So far I blamed the xslt processing for the low performance and since about a quarter I am working on a (python) tool in gtk-doc that reads the docbook with lxml (xml module that uses libxml2) and then walks the tree a few time and produces chunked html similar to the docbook stylesheets. The tool is getting feature complete and is up to 10 times faster (despite python). One reason I believed xslt is slow is that it is single threaded and when I added multi-threding/processing to my python tool I was puzzled that it does not get much faster. At this point I added some benchmarking and found out that the biggest chunk of time it spend on loading the xml. Lets look at some numbers using glib (https://gitlab.gnome.org/GNOME/glib) cd glib/docs/reference/glib xmllint --timing --xinclude --noout glib-docs.xml Parsing took 0 ms Xinclude processing took 4560 ms Freeing took 91 ms Any idea how I can get more breakdown of whats happening in 'Xinclude processing'? Running with "perf record -g -- xmllint --timing --xinclude --noout glib-docs.xml" gets me such a report. + 17.15% 16.69% xmllint libc-2.24.so [.] _int_malloc + 11.93% 11.87% xmllint libc-2.24.so [.] malloc_consolidate + 9.01% 8.97% xmllint libxml2.so.2.9.4 [.] xmlDictLookup + 7.15% 0.00% xmllint ld-2.24.so [.] 0xffff8021a0022010 + 6.25% 6.21% xmllint libxml2.so.2.9.4 [.] xmlHashAddEntry3 + 6.22% 0.00% xmllint libxml2.so.2.9.4 [.] xmlSAX2IsStandalone + 6.22% 0.00% xmllint [unknown] [.] 0x56413c74c0854810 + 3.95% 3.94% xmllint libxml2.so.2.9.4 [.] xmlHashLookup2 3.72% 3.70% xmllint libc-2.24.so [.] _int_free + 3.28% 0.00% xmllint [unknown] [.] 0000000000000000 + 3.06% 3.04% xmllint libxml2.so.2.9.4 [.] xmlFreeDocElementContent + 2.96% 2.91% xmllint libc-2.24.so [.] free Trying a different allocator seems to help quite a bit too (xtime is an alias for /usr/bin/time -f '%Uu %Ss %er %MkB %C' "$@") rm html-build.stamp; ~/bin/xtime make docs 53.28u 0.99s 54.70r 202372kB make docs rm html-build.stamp; LD_PRELOAD=/usr/lib/libtcmalloc_minimal.so.4.3.0 ~/bin/xtime make docs 42.48u 1.54s 44.48r 185404kB make docs -> saves ~11sec when using the original toolchain (libxml2 + libxslt with docbook-stylesheets) ~/bin/xtime python3 ~/projects/gnome/gtk-doc/gtkdoc-mkhtml2 glib glib-docs.xml 7.01u 0.25s 7.27r 146068kB python3 /home/ensonic/projects/gnome/gtk-doc/gtkdoc-mkhtml2 glib glib-docs.xml LD_PRELOAD=/usr/lib/libtcmalloc_minimal.so.4.3.0 ~/bin/xtime python3 ~/projects/gnome/gtk-doc/gtkdoc-mkhtml2 glib glib-docs.xml 5.69u 0.39s 6.10r 137340kB python3 /home/ensonic/projects/gnome/gtk-doc/gtkdoc-mkhtml2 glib glib-docs.xml -> saves ~1.5sec with my new toolchain (mostly on the loading xml side). Any ideas. Is there a know issues with using xincludes here? Stefan _______________________________________________ xml mailing list, project page http://xmlsoft.org/ [email protected] https://mail.gnome.org/mailman/listinfo/xml