Posix threads in RHAT9

[Paul Iadonisi]

On Wed, 2004-05-19 at 14:41, Michael ODonnell wrote:

[snip]

> I don't yet feel like I know know where things stand, but FYI
> I've heard (since my OP) that there was (is?)  apparently enough
> trouble caused by the NPTL (eg, to the threading infrastructure

  I guess it depends on your point of view.  Many view the old Linux
thread model as broken.  Apps that don't work under the new model
(including the Sun JVM *itself*, IIRC) are what need(ed) to be fixed,
IMNSHO.

> of various Java packages) that it was arranged that you can
> force NPTL disabled either by booting your RHAT kernel with the
> "nosysinfo" commandline option, or else run your apps after
> saying "export LD_ASSUME_KERNEL=<kernel-version>" where 2.4.1
> means "Linuxthreads with floating stacks" and 2.2.5 means
> "Linuxthreads without floating stacks".

  Well, yeah, but that's pretty standard, isn't it?  Providing a
temporary workaround to use an old feature until everyone's on board
with the new, less calories, less fat, more caffeine :-) feature?  I
have to boot my newly installed FC2 system with vdso=0 because it's
broken on my system (don't ask, I have no idea what vdso is either). 
But I won't dis vdso just because it doesn't work for me (yet?).
  Anyhow, the LD_ASSUME_KERNEL thing has been there for a while and I
*thought* it was not really a Red Hat-only feature.  I really don't
think it was added by Red Hat after the fact in response to the trouble
it caused after the nptl kernel was released, evidenced by the fact that
it's been in existence since before nptl was introduced.
  For the record, I can't speak authoritatively about which thread model
is better or worse.  I only know what I know from reading various places
(lwn.net kernel section, kerneltrap.org, and sometimes lkml itself) what
was, is, and is going to be in various kernel versions.
--
-Paul Iadonisi
 Senior System Administrator
 Red Hat Certified Engineer / Local Linux Lobbyist
 Ever see a penguin fly?  --  Try Linux.
 GPL all the way: Sell services, don't lease secrets