Re: GUILE 2/3 and string encoding cost

[Han-Wen Nienhuys]

On Wed, Jan 22, 2020 at 10:53 PM Han-Wen Nienhuys <address@hidden> wrote:

>
>
> On Wed, Jan 22, 2020 at 12:01 PM David Kastrup <address@hidden> wrote:
>
>>
>> > So, what hard data do we have on GUILE 2/3 slowness, and what does
>> > that data say?
>>
>> That data says "humongous slowdown".  There is not much more than
>> speculation what this is caused by as far as I know.
>>
>
> I can see the 2x slowdown, and it looks uniformly distributed over the
> whole process. The GUILE 2.0 release
>

Actually, the I was comparing the -O2 build with the -O0 build.

When recompiling, the Scheme init (reading .scm files) takes 0.31s in 1.8
vs. 2.7s in 2.0, a 9x slowdown.





>   https://lwn.net/Articles/428288/
>
> has one big red flag for me.
>
>   * Switch to the Boehm-Demers-Weiser garbage collector
>
>   Guile now uses the Boehm-Demers-Weiser conservative garbage collector
>   (aka. libgc).  It makes interaction with C code easier making, for
>   instance, the use of mark and free SMOB procedures optional in many
>   cases.  It also improves performance.
>
> let me get out the profiler to see what is going on.
>
> --
> Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen
>


-- 
Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen