Hi Richard (et al), On 28 November 2014 at 14:04, Richard W.M. Jones <rjones@xxxxxxxxxx> wrote: > On Fri, Nov 28, 2014 at 05:49:39AM -0700, T.C. Hollingsworth wrote: >> Replying by phone because holidays, sorry for any faux pas. > > No problem, thanks for the quick reply! > >> On Nov 28, 2014 4:15 AM, "Richard W.M. Jones" <rjones@xxxxxxxxxx> wrote: >> > >> > Hello Tom and other v8 maintainers. >> > >> > I was looking at porting the Fedora Rawhide v8 package to aarch64, >> > since it is a dependency of mongodb, and hence an indirect dependency >> > of OpenStack Ceilometer. >> > >> > The bad news is that there is no aarch64 support in the current Fedora >> > package. The good news is that upstream v8 from git has aarch64 >> > support. The not so good news is that it's not completely working. >> > >> > Firstly at the moment you're building from SVN-generated tarballs (is >> > that right?). V8 recently moved to using git. How do you feel about >> > using git tags instead? The latest git tag is 3.31.27 which was >> > released earlier today. That tag has the aarch64 support. >> >> We don't typically track all v8 releases since they break API and ABI on a >> monthly basis and are quickly no longer supported by Google. We do track v8 >> releases used by stable versions of node.js, since these are typically >> maintained for years. >> >> As of right now, it looks like the upcoming nodejs 0.12 release will use >> the 3.30 branch (it currently ships 3.30.37). aarch64 has been "officially >> supported" since 3.25. >> >> If aarch64 support works in 3.30 just as well as 3.31, I'd suggest focusing >> your polishing efforts there (along with fixing master as appropriate), so >> it can last for awhile. If 3.31 is really better I may be able to push to >> get node bumped upstream to make everyone's life easier. > > I tested 3.30.37 and aarch64 support seems to be at the same level as > head. > > The precise same set of 636 tests fail too. However looking more > closely, (1) all the tests are in the same bit of code which is > something to do with math libraries AFAICT, and (2) the JIT makes > debugging it very difficult - there are no stack frames so gdb can't > make head nor tail of it. I suggest we ignore the test failures unless > they actually affect mongodb/nodejs. > > Anyway the bottom line is that 3.30.37 is fine. > >> 3.) MongoDB will need to be ported to work with newer v8. There have been >> massive changes to the v8 API in recent versions (which is part of the >> reason it has taken so long to get from node 0.10 to node 0.12). AFAICT no >> porting effort has even been considered by mongodb upstream yet. [Actually, >> they ship it with an even older version of v8 than we use it with in >> Fedora. :-( ] >> >> As of this moment my current plan to maintain mongodb support in Fedora is >> to introduce a compat-v8-314 package at the same time we bump v8 to 3.30. >> Which will be no problem supporting for a couple more years at least, but >> it's still basically on life support and that doesn't bode well for arm64 >> support. >> >> You may want to talk to mongodb upstream first and foremost and inquire >> about getting it to work with newer v8 versions. I'd hate for you to do a >> bunch of work fixing v8 on arm64 just for it to only end up benefitting >> Chrome for Android users. ;-) > > Bluuurrrrggggghhhhhhh. Professional engineering practices FTW. > > There's an upstream mongodb bug about this which doesn't look > encouraging: > https://jira.mongodb.org/browse/SERVER-10282 > Funnily enough the whole embedded v8 issue cam up at work and I spoke to one of the guys at MongoDB. In a nutshell, AArch64 is not a priority for them at present :-( They don't have the resources to put on the task, so it is a community effort only for now. There are also another couple of bugs for reference: https://jira.mongodb.org/browse/SERVER-1811 https://jira.mongodb.org/browse/SERVER-13828 One thing to note with MongoDB is that they have changed their storage engine to WiredTiger (http://www.wiredtiger.com/), I haven't had a chance to see if this will also pose any issue for ARM. Regards, Andy > Rich. > _______________________________________________ arm mailing list arm@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/arm
