"Sergey A. Osokin" <osa%NetBSD.org@localhost> writes:
> On Thu, Mar 17, 2022 at 08:11:37AM -0400, Greg Troxel wrote:
>> "Sergey A. Osokin" <osa%NetBSD.org@localhost> writes:
>>
>> > hope you're doing well these days.
>> > I've just realized that jit is disabled for devel/pcre.
>> > In FreeBSD ports tree jit is enabled for various platforms, i.e.:
>> >
>> > .if ${ARCH} != "sparc64" && empty(ARCH:Mmips64*) && empty(ARCH:Mriscv64*)
>> > CONFIGURE_ARGS+= --enable-jit
>> > .else
>> > CONFIGURE_ARGS+= --disable-jit
>> > .endif
>>
>> That looks like enabled except for 3, which seems like a clue that not
>> very many platforms are used with FreeBSD ports, but maybe I'm
>> misreading.
>>
>> > Is it good idea to enable the feature for some platforms?
>>
>> Perhaps, but
>>
>> 1) On which platforms did you enable and test, and how did it go in general?
>
> I have the one at the moment, and it's amd64.
So you could conceive of enabling it for that NetBSD/amd64 only.
But, we are days away from freeze, and I think this is best left until
after the freeze to change it by default.
You could add a jit option, default off, and let people turn it on, and
you could turn it on yourself. (I might too.) Then later the option
can default to on for tested platforms.
>> 2) Did you measure it to be faster?
>
> Personally not, but there're many articles and blog posts about performance
> improvement when pcre configures and compiles with --enable-jit option.
>
>> 3) Did you run the included selftests and do they still pass? Did you
>> build things that use it and run their tests?
>
> For selftests - since those are included into a distribution, I believe
> the vendor executes those for every new release.
Yes, but did you run the tests on your machine, with the jit as built by pkgsrc?
Did you build something that uses it, and verify that its tests work,
and that the program works?
I think the disconnect in our approaches is that I view a jit compiler
as something that could have bugs in some environments, and until the
actual build has been tested, in a particular os/cpu pkgsrc
environment.
>> 4) Do you understand how the jit interacts with paxctl? For guile
>> 3.0, there is a compiler, and we have, so far, had to disable
>> MPROTECT. I wonder what your experience was.
>
> Nope, I have no experience with that.
Attachment:
signature.asc
Description: PGP signature