Re: [dev-servo] meeting notes (COW DOM)

2014-07-07 Thread Cameron Zwarich
On Jul 7, 2014, at 7:11 PM, Robert O'Callahan wrote: > zwarich: JITting will give a huge benefit. > > Are there experimental results showing this? Because I haven't seen any > yet, and I'd like to :-). There is this blog post: https://www.webkit.org/blog/3271/webkit-css-selector-jit-compiler/

Re: [dev-servo] meeting notes (COW DOM)

2014-07-07 Thread Patrick Walton
On 7/7/14 7:11 PM, Robert O'Callahan wrote: Difficult, definitely. Performance problem ... now that we have incremental CC and bunch of other optimizations, I feel like it isn't. At least compared to any other viable GC approach, all of which have their own performance pitfalls. Safety problem ..

Re: [dev-servo] meeting notes (COW DOM)

2014-07-07 Thread Robert O'Callahan
On Tue, Jul 8, 2014 at 2:56 PM, Patrick Walton wrote: > Yeah, I shouldn't have mentioned safety there, since the fundamental > problem is the same whether or not you use CC or GC. You still have to > teach the JS engine or the CC about the object graph. > > We use compiler support for this in Rus

Re: [dev-servo] meeting notes (COW DOM)

2014-07-07 Thread Robert O'Callahan
On Tue, Jul 8, 2014 at 2:55 PM, Cameron Zwarich wrote: > There is this blog post: > > https://www.webkit.org/blog/3271/webkit-css-selector-jit-compiler/ > > I’m friends with the author and have anecdotal confirmation that the > improvements also occur on real web pages. > Good. I saw that, but w

Re: [dev-servo] meeting notes (COW DOM)

2014-07-07 Thread Patrick Walton
On 7/7/14 8:07 PM, Robert O'Callahan wrote: The pragmatist in me loves it :-). There's probably a principled way to implement ForgetSkippable in a way that's automatically checkable. Having said all that, I'm not necessarily advocating GC+CC for Servo. It is a hard and complex approach. I'm sti

Re: [dev-servo] meeting notes (COW DOM)

2014-07-08 Thread Andrew McCreight
- Original Message - Not to derail this further with a defense of the CC, but... > CC is still a performance and memory and safety problem. At this point, I think the GC is a bigger performance problem. ;) Ok, so it is doing much more stuff than the CC... > Yeah, I shouldn't have men

Re: [dev-servo] meeting notes (COW DOM)

2014-07-09 Thread smaug
On 07/08/2014 05:56 AM, Patrick Walton wrote: On 7/7/14 7:11 PM, Robert O'Callahan wrote: Difficult, definitely. Performance problem ... now that we have incremental CC and bunch of other optimizations, I feel like it isn't. At least compared to any other viable GC approach, all of which have th

Re: [dev-servo] meeting notes (COW DOM)

2014-07-09 Thread Robert O'Callahan
On Wed, Jul 9, 2014 at 8:23 AM, smaug wrote: > In general issues with GC handling are security bugs, but in CC they lead > to leaks. > > I could note that max median CC times have been lower than max GC slice > times at least since early 2012. > CC needs to deal with possible garbage only, GC ten

Re: [dev-servo] meeting notes (COW DOM)

2014-07-09 Thread Patrick Walton
On 7/8/14 1:23 PM, smaug wrote: In general issues with GC handling are security bugs, but in CC they lead to leaks. This is not the case in Servo, though; we should be foolproof for both. I'm definitely not willing to compromise on memory safety. :) Blink doesn't have a collector for refcou

Re: [dev-servo] meeting notes (COW DOM)

2014-07-09 Thread Patrick Walton
On 7/9/14 2:48 PM, Robert O'Callahan wrote: If you think so, then I think we *should* be considering GC+CC for Servo. Crazy idea: could it even make sense for JS GC to use a traced nursery and a refcounted+CC tenured space? This is more or less how RC-immix works, right? http://users.cecs.anu

Re: [dev-servo] meeting notes (COW DOM)

2014-07-09 Thread Cameron Zwarich
On Jul 9, 2014, at 2:48 PM, Robert O'Callahan wrote: > On Wed, Jul 9, 2014 at 8:23 AM, smaug wrote: > >> In general issues with GC handling are security bugs, but in CC they lead >> to leaks. >> >> I could note that max median CC times have been lower than max GC slice >> times at least since

Re: [dev-servo] meeting notes (COW DOM)

2014-07-09 Thread Robert O'Callahan
On Thu, Jul 10, 2014 at 9:53 AM, Patrick Walton wrote: > On 7/8/14 1:23 PM, smaug wrote: > >> In general issues with GC handling are security bugs, but in CC they >> lead to leaks. >> > > This is not the case in Servo, though; we should be foolproof for both. > I'm definitely not willing to compr

Re: [dev-servo] meeting notes (COW DOM)

2014-07-09 Thread Robert O'Callahan
On Thu, Jul 10, 2014 at 9:56 AM, Patrick Walton wrote: > On 7/9/14 2:48 PM, Robert O'Callahan wrote: > >> If you think so, then I think we *should* be considering GC+CC for Servo. >> >> Crazy idea: could it even make sense for JS GC to use a traced nursery >> and a refcounted+CC tenured space? >>