On Fri, 2010-10-22 at 16:34 -0400, William L. Thomson Jr. wrote: > > In fact when java-config (written in Python) performance improves its > because of data being cached in disk operations. At a much lower level, > and nothing to do with Python at all, which is starting and stopping on > every run.
FYI I am not doing a comparison of languages. I am seeking to do real world use case comparisons. This is one of the major problems regarding Gentoo's Java tools I am seeking to speeding up. This is just one of many functions, but this is the slowest, most major operation. The files its touching are tiny, and its only touching 243 files. java-config -l | wc -l 243 Files are package.env files that look like the following DESCRIPTION="Reads XML configuration files to provide initialization of various Java objects within the system." GENERATION="2" SLOT="0" CATEGORY="dev-java" PVR="1.8.1-r1" CLASSPATH="/usr/share/commons-digester/lib/commons-digester.jar" DEPEND="[email protected]:commons-collections....@commons-collections:commons-logging....@commons-logging" VM=">=virtual/jre-1.4" TARGET="1.4" SOURCE="1.4" MERGE_VM="icedtea6-bin" MERGE_COMPILER="ecj-3.5" The output is not sorted, so no additional processing time there. Just open file, read it into an array/vector, close file, and output results. time java-config -l real 0m11.320s user 0m0.410s sys 0m0.120s real 0m0.446s user 0m0.280s sys 0m0.070s real 0m0.512s user 0m0.300s sys 0m0.060s real 0m0.469s user 0m0.280s sys 0m0.070s That is ridiculously slow IMHO (can blame the disk I/O in part). Another C app I wrote, asspr, will hit thousands of emails, much larger than any package env file, and return output in much less time. Even with a hit on initial run till disk cache kicks in, still much faster. Now I have run the above many times on different machines. There is always a few second delay if there is nothing in the disk cache. Once its run, if anything is cached, even after a while. Performance is as bad, but I won't say its good either. Either way its rarely run back to back like that, with disk cache remaining. Which cache may remain as you are compiling and installing packages, but more likely not. I will be shocked if after I recode java-config -l in C and its speed does not improve substantially. Much less for other operations. -- William L. Thomson Jr. Obsidian-Studios, Inc. http://www.obsidian-studios.com This message (including any attachments) contains confidential information intended for a specific individual and purpose, and is protected by law. If you are not the intended recipient, you should delete this message. Any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited. --------------------------------------------------------------------- Archive http://marc.info/?l=jaxlug-list&r=1&w=2 RSS Feed http://www.mail-archive.com/[email protected]/maillist.xml Unsubscribe [email protected]
