+kentaro for some profiling insights
On Tue, Jun 11, 2013 at 7:24 AM, Adam Klein <ad...@chromium.org> wrote: > I'm trying to profile the v8 execution of a web app using Chromium's > content_shell with some success. But I'm also getting some odd > results. I'm using a commandline like: > > content_shell --no-sandbox --js-flags='--prof --noprof-lazy > --log-timer-events' http://localhost:8000/mypage > > And then processing the v8.log with > > v8/tools/linux-tick-processor v8.log > > The resulting profile has some quirks: none of the "JavaScript" > portion of the profile lists more than 0.2% of the total ticks (even > though there's >500ms of JS execution time as part of the app, as > shown by both plot-timer-events and the Inspector's timeline). The C++ > stack, meanwhile, has several major points of interest. Most of the > big ones are Blink C++ callbacks (e.g., > NodeV8Internal::dispatchEventMethodCallback), and __pthread_cond_wait > shows up. But the top one is "__write", usually taking >30% of the > ticks. > > If I go down to the call stacks, I get a bunch of "LazyCompile > someMethod" entries which terminate at __write, so it seems I'm still > getting some idea of which JS is taking the time, but I'm rather > surprised that __write is the endpoint (it's mostly DOM tree > walking/manipulation). Is this expected? > > Also, I'm a bit surprised at the way the v8 DOM callbacks end up in > the profile: those methods are usually trivial, with the real work > being somewhere deep in the core of Blink. Is it expected that only > the v8 entry point into Blink shows up when using the profiling tool? > > Any insights would be valuable. > > Thanks, > Adam > > -- > -- > v8-users mailing list > v8-users@googlegroups.com > http://groups.google.com/group/v8-users > --- > You received this message because you are subscribed to the Google Groups > "v8-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. > > > -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
