Hello Stefan, Do You think it is possible to allocate xml/xsl in shared memory? My wsgi application uses lxml to parse config files (xml) and xls stylesheets. Both configs and xsl parsed at application start and do not modified till application exists. Rss for 1 process just after xml/xsl parsing grows 15Mb (production - 15 modules) and 35 Mb (debug - 25 modules). The modules numbler will only grow in time. Currently we have 50 workers - so 15Mb * 50 = 750Mb for xml/xsl that never changes. I suppose it is not shared across forks because of python incref/decref nature but i may be wrong? Do you think it will be possible to use xmlMemSetup ( http://xmlsoft.org/html/libxml-xmlmemory.html#xmlMemSetup ) to setup xmllib to use custom malloc that will be using mmap? How lxml will behave if i do so? Do any xslt object internal structures changed while i call xslt(xml_doc) from python? -- -------------------------------------------- Турнаев Евгений Викторович +7 906 875 09 43 --------------------------------------------