Re: KSE, libpthread & libthr: almost newbie question

Ruslan Ermilov wrote:
On Fri, Oct 27, 2006 at 10:56:21AM +0200, Ivan Voras wrote:
Lev Serebryakov wrote:
Hello ,

I've was sure, that both libpthread and libthr use KSE to make multithreading. They use KSE in different ways: libpthread uses N:M model and libthr uses 1:1 model, but bot use KSE to work.
How will be possible to use these libraries (read: multithreaded programs) when KSE will be optional, on kernel without KSE?!
Yes, isn't KSE by definition "that thing that is scheduled in the kernel"?

KSE == N:M threading

A 1:1 threading (libthr) is much simpler than N:M threading (libpthread),
and thus doesn't require KSE support in the kernel; see kse(2) manpage
for details. Without the KSE option in the kernel, all kse(2) syscalls
will return EOPNOTSUPP, and a lot of code becomes redundant.


KSE is a misnomer that I abandoned long ago..
mostly it is the thread fairness code that is independent of what threading library is running (see the other email I just sent)
(or should be)


: /*
: * Initialize global thread allocation resources.
: */
: void
: threadinit(void)
: {
: : mtx_init(&tid_lock, "TID lock", NULL, MTX_DEF);
: tid_unrhdr = new_unrhdr(PID_MAX + 1, INT_MAX, &tid_lock);
: : thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(),
: thread_ctor, thread_dtor, thread_init, thread_fini,
: UMA_ALIGN_CACHE, 0);
: #ifdef KSE
: ksegrp_zone = uma_zcreate("KSEGRP", sched_sizeof_ksegrp(),
: ksegrp_ctor, NULL, NULL, NULL,
: UMA_ALIGN_CACHE, 0);
: kseinit(); /* set up kse specific stuff e.g. upcall zone*/
: #endif


The KSEGRP is a part of the fairness code in general and independent
of M:N and 1:1

: }


Cheers,
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