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Re: [MIT-Scheme-devel] floating-point environment
From: |
Taylor R Campbell |
Subject: |
Re: [MIT-Scheme-devel] floating-point environment |
Date: |
Sat, 9 Oct 2010 19:24:15 +0000 |
User-agent: |
IMAIL/1.21; Edwin/3.116; MIT-Scheme/9.0.1 |
Date: Fri, 8 Oct 2010 09:15:17 -0700
From: Joe Marshall <address@hidden>
>> Â Date: Thu, 7 Oct 2010 12:38:59 -0700
>> Â From: address@hidden (Matt Birkholz)
>>
>> Â Can a Scheme-side cache of the machine configuration avoid much of the
>> Â cost of thread switching by punting fesetenv() when switching to a
>> Â thread with the same expectation of the floating-point environment?
I'd be surprised if thread-switching were frequent enough that this would
make
a difference.
Currently Scheme switches threads every tenth of a second, but I think
that's much too long a delay, actually; Edwin becomes almost unusable
with that delay. I often set TIMER-INTERVAL to be a millisecond,
which is the finest resolution the microcode supports at the moment,
although I'd also like to add primitives to support nanosecond-
resolution time operations, using the POSIX clock_* routines.
Anyway, I'll try to measure the performance difference once I
implement the changes to CWCC. From what I recall, actually, a huge
portion -- something like 95% -- of the time spent by CWCC or non-
local continuation invocation is spent copying the interpreter's
history.
On Thu, Oct 7, 2010 at 8:57 PM, Taylor R Campbell <address@hidden> wrote:
> What I have in mind is for every
> continuation invocation -- including those used to switch threads --
> to do fesetenv.
I assume you mean every *non-local* continuation.
Oops -- you're right! That is what I meant.
- [MIT-Scheme-devel] floating-point environment, Taylor R Campbell, 2010/10/06
- Re: [MIT-Scheme-devel] floating-point environment, Taylor R Campbell, 2010/10/07
- [MIT-Scheme-devel] floating-point environment, Matt Birkholz, 2010/10/07
- Re: [MIT-Scheme-devel] floating-point environment, Taylor R Campbell, 2010/10/07
- Re: [MIT-Scheme-devel] floating-point environment, Matt Birkholz, 2010/10/13
- Re: [MIT-Scheme-devel] floating-point environment, Taylor R Campbell, 2010/10/13
- Re: [MIT-Scheme-devel] floating-point environment, Matt Birkholz, 2010/10/14
- Re: [MIT-Scheme-devel] floating-point environment, Taylor R Campbell, 2010/10/15
- Re: [MIT-Scheme-devel] floating-point environment, Matt Birkholz, 2010/10/22
- Re: [MIT-Scheme-devel] floating-point environment, Taylor R Campbell, 2010/10/23