You're probably almost hitting the maximum heap size. The profile indicates that the program spends almost 100% time in the garbage collector. You could try running with a larger heap, but in general JS objects in V8 are not optimized to be used as large hash tables. Most likely, it would be best to implement your own hash table data structure using an array as a backing store instead of using a JS object as a hash table.
2012/5/11 Joran Greef <[email protected]> > I am using V8 as part of Node and have written a Javascript implementation > of Bitcask, using a Javascript object as a hash to keep file offsets in > memory. > > This object has 7 million entries and I'm noticing that while the JS code > is resting, doing nothing, V8 is hitting 100% CPU every few seconds and > doing this continually. > > Attached is the full result of running V8 with --prof. > > And of particular interest: > > [C++]: > ticks total nonlib name > 73615 43.1% 43.1% > v8::internal::StaticMarkingVisitor::VisitUnmarkedObjects > 68436 40.1% 40.1% _accept$NOCANCEL > 4796 2.8% 2.8% > v8::internal::FlexibleBodyVisitor<v8::internal::StaticMarkingVisitor, > v8::internal::JSObject::BodyDescriptor, void>::VisitSpecialized<40> > > Should I be using many smaller hashes to keep this overhead down? i.e. > some sort of sparse hash implementation? Or using key mod 1000 to determine > the hash it should be in? > > Does V8 have limits on hash table sizes? > > Thanks. > > -- > v8-users mailing list > [email protected] > http://groups.google.com/group/v8-users -- v8-users mailing list [email protected] http://groups.google.com/group/v8-users
