[M3devel] user threads

[Mika Nystrom]

Of course I just realized this typecase business doesn't work.  
Not thread-safe.

The numbers for CM3 are worse than I write... sigh, ok, back to the
drawing board.

Mika Nystrom writes:
>By the way, *all* my CM3 timings have my Typecase modification,
>which isn't checked in to the distribution.  I think they would all
>be about 400 ms slower if they didn't have that.
>
>A bit of "poor man's profiling" shows the program still spending
>quite some time in RTType.IsSubtype (called from CheckIsType).
>I think that accounts for most of the remaining difference between
>PM3 and CM3.
>
>     Mika
>
>Mika Nystrom writes:
>>Ok, it works!
>>
>>Numbers:
>>
>>Timings in milliseconds, three samples, filesystem "warmed up" by
>>doing one dummy run before launching the real ones.
>>
>>-unsafe means that I use non-locking Scheme environments, otherwise
>>they lock for every variable update.
>>                                                             ave  
>>CM3 last week, kernel threads, -unsafe   1460  1482  1437   1460
>>CM3 last week, kernel threads,           2392  2402  2376   2390
>>CM3 this week, kernel threads, -unsafe   1455  1458  1490   1468 (*)
>>CM3 this week, user threads,   -unsafe    914   934   914    921
>>CM3 this week, user threads,              967   965   986    973
>>PM3                            -unsafe    678   657   682    672
>>PM3                                       709   714   700    708
>>
>>(*) not entirely sure this got linked correctly.
>>
>>    Mika
>>             
>>
>>Jay writes:
>>>
>>>User threads seem to work on on FreeBSD/x86 7.0.
>>>Mika can you report back the perf cm3 vs. pm3?
>>>Still, kernel threads have been around a long time and imho should be strongly favored..
>>> 
>>> 
>>>Kernel threads should be a /little/ faster than they were -- PushEFrame removed from successful heap allocations. And should be further improvable via __thread where it is supported -- probably not FreeBSD 
>4
>>.
>>>x, sometimes older is not better. :)
>>> 
>>> 
>>>I've temporarily switched FreeBSD/x86 to userthreads by default but I think that's just an experiment and should be undone shortly, maybe work out some other story for easily switching between them, or just
> 
>>k
>>>eep the existing story of "you get to rebuild everything".
>>> 
>>> 
>>>Tony, can you look into GetGCRatio? I removed the call to it. The "fatal" pragma invokes PushEFrame apparently.
>>> 
>>> 
>>>We should now "fix" Win32 and pthreads to not have GetActivation initialize on-demand, just leave Init to initialize always. This should shave a few more cycles from PushEFrame.
>>> 
>>> 
>>> - Jay