Am Sonntag, den 08.04.2012, 00:59 +0200 schrieb Ben Noordhuis: > On Sun, Apr 8, 2012 at 00:38, Jann Horn <jann...@googlemail.com> wrote: > > Hello, > > I've been using a little ad-filtering proxy I built using node for some > > time now, and today I had a look at its CPU usage while flash was > > prefetching a very large youtube video. Well, it was relatively high, I > > think, but the only thing it should be doing at that time is using > > the .pipe() method to pipe from one HTTP stream to another one. > > > > Well, I was surprised to see that node was wasting ~2.5% of its CPU > > usage on v8::String::New calls in node::MakeCallback, and that > > node::MakeCallback in total has a CPU overhead that amounts to ~7% of > > the total CPU time node uses in this case. Shouldn't it at least be > > possible to cache the symbol string? And couldn't node maybe also avoid > > calling v8::Object::Get each time it wants to call into userland (~3.6% > > )? > > > > Are these things right or did I make some huge mistake? If they are > > right, would it be possible to make this stuff a bit faster? Reducing > > the CPU usage by 5% seems like a relatively big speed improvement to me. > > > > Node version: 0.6.14 > > > > Call graph centered on MakeCallback: > > http://thejh.github.com/callgraph.png > > > > Raw callgrind output: > > http://thejh.github.com/callgrind.out.19701 > > Yes, it's a known issue and something we'll address in v0.8, probably > by scrapping MakeCallback() and moving back to Persistent<T> handles.
Wasn't MakeCallback() also supposed to handle the domains stuff? And don't many C++ modules use that?