signalling remote threads

[Julian Elischer]

Jeremie Le Hen wrote:
> Hi Martin,
> 
> On Sat, Mar 10, 2007 at 01:32:26AM +0100, Martin Blapp wrote:
>> Hi,
>>
>>> There is no portable way to identify threads in another process. There is 
>>> also no guarantee that the tread is even externally visible. Take
>> But is it true for FreeBSD that 'ps -Hauxwww' should show all threads
>> for a process with libc_r, libpthreads.so, or libthr.so ?
> 
> May I advice you to read these two posts for a thorough explanation.
> 
> http://lists.freebsd.org/pipermail/freebsd-threads/2006-August/003674.html
> http://lists.freebsd.org/pipermail/freebsd-threads/2006-August/003682.html
> 


This is true, however it is a bit out of date because the thread group
facility that gives scheduler fairness (talked about in the second reference)
has been ripped out of -current due to no-body thinking it was needed.
and a general thought that the added complexity was not worth the result.
Generally it made the scheduler much more complicated. What is said about
SA is however still true if that threading facility is chosen.
it still leads to some scheduler fairness as only NCPU threads from the process
are put onto the kernel run queue at a time.