Zitat von Dariusz Mazur <[email protected]>:
[...]
Most of programs are huge count of simple computing. There are many
places, that things may run parallel without pain. But very often
this places are computing short, thus very often overhead of
starting thread is bigger than using second core. But CILK
potentially (I can prof that, only imagine) reduce this overhead.
Second : its very readability solution, and compiler potentially can
warning about some danger . If we try to concurrency smaller things,
without loss efficiency, danger will be minimize
Start a wiki page with a proposal for the syntax.
Create a unit like mtprocs that demonstrates CILK and how the syntax
should be converted by the compiler.
Find someone to implement and, more important, maintain this.
Then there is a good chance to get this into the fpc main branch.
[...]
Even the mtprocs does that.
http://wiki.lazarus.freepascal.org/Parallel_procedures#Features
realy?
cite:" a procedure or method is executed with an Index running from
an arbitrary StartIndex to an arbitrary EndIndex"
assigning iteration to threads are done on start loop, eq. we must
know count of iteration.
what when iteration 1 is ten times longer than rest?
Then the other threads will sleep OR if this is a nested sub procedure
the other threads will continue on the other work.
For example:
for i:=1 to 10 paralleldo
for j:=1 to 10 paralleldo begin
if j=1 then DoAlotOfWork else DoLittleWork;
end;
With mtprocs all threads will work until the end when the everything
was done except the last DoAlotOfWork, which is then executed by only
one thread.
mtprocs is just a unit, it can not auto parallelize DoAlotOfWork as a
compiler could.
[...]
I thinking about Fifo queue, I use one Lock free,
its need 16 byte per spawn (func addres, param and result)
time of swich less than 1us
Are you sure about the 1us switch? The algorithm looks more dramatic.
problem is with assigning local stack per task, my asm is too weak.
Mattias
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