On Thu, Nov 6, 2014 at 4:43 PM, Sebastian Kügler <se...@kde.org> wrote: > On Thursday, November 06, 2014 10:09:51 Mark Gaiser wrote: >> I'm curious about one thing. Have you done some profiling on the >> current KPluginMetaData to see where the actual hot spot is? >> In case you don't know how to do that, here are some tips: >> 1. Recompile Qt with debug symbols (not debug mode, just with the debug >> symbols) 2. Run a benchmark application via valgrind like so: valgrind >> --tool=callgrind <your_benchmark_app> >> 3. Open the output file of the line above in KCacheGrind and hunt for >> those pesky hot spots. >> >> Perhaps there is nothing to optimize and then having an index (and the >> cost of maintaining it) is worth it, but it would be best to first >> determine if the current code path can be optimized. > > I've focused on reducing the I/O, since that's where we spend by far most of > the time, somewhere beyond 90% of the whole time it takes to run the query > (and in worse cases with cold caches and on rotational media, even more). > > The next bottleneck would be the deserialization of json data, which is for > the binary format we use for storage (and I think which is also used in > QPluginLoader to read the plugins json metadata). As fas as I can see, that is > also pretty much entirely I/O bound. > > There may be something to be gained in the conversion from the KPluginMetaData > list to the KPluginInfo::List by making the query runner 'understand' > KPluginMetaData (it knows KService and KPluginInfo currently) but that's > definitely not a bottleneck currently. > > In the whole picture, KPluginMetaData is not a concern right now, reducing the > I/O is what we need to do first. > > Cheers,
Ah right, i think i missed the I/O reducing goal in your initial post. I haven't checked your draft implementation in detail, but what you might want to do is: - Monitor all plugin folders for changes - If a change in any of the folders is detected: rebuild cache. That should keep the cache updated in a fairly easy way and remove the need to have a tool at all. You could do it more fine grained and only update the cache for the plugin that changed. It will be a bit more tricky to implement. Just an idea, but i hope it helps. Cheers, Mark _______________________________________________ Kde-frameworks-devel mailing list Kde-frameworks-devel@kde.org https://mail.kde.org/mailman/listinfo/kde-frameworks-devel
