Re: LinuxThreads or other alternatives for the Hurd/{Mach,L4}?

[Michael Hohmuth]

Farid Hajji <address@hidden> writes:

> The reason why we need an N:M library is, that we are planning to port
> the Hurd from Mach to the L4 microkernel. Unfortunately, the Hurd uses
> threads very heavily, and L4 provides only a limited number of native
> threads per task (128 or so), so there is a need for a multiplexing
> library.

When you seriously start looking at an L4 port, I suggest you start
out by using a 1:1 user--kernel thread mapping.  I suggest this for
two reasons.  First, in practice the limit of kernel threads per task
has rarely been a problem in L4 development.  Second, as IPC messages
in L4 are addressed to kernel threads, using an N:M mapping
complicates matters.

That said, I think I know of three free N:M thread libraries:

- Already mentioned on this mailing list: Next Generation POSIX
  Threading Project --
  <URL:http://oss.software.ibm.com/developerworks/opensource/pthreads/>

- Last USENIX had a paper about a Solaris-compatible thread library --
  <URL:http://www.usenix.org/events/usenix01/freenix01/wood.html>.
  Solaris has N:M threading, and the library is said to be
  API-compatible, but I don't know if it also implements N:M.

- Isn't Mach's cthreads library also an N:M implementation?

[ Cc list trimmed to include just l4-hurd mailing list ]

Michael
-- 
address@hidden, address@hidden
http://home.pages.de/~hohmuth/