This basically means to get rid of sysdeps/mach/hurd/bits/libc-tsd.h (and thus the _HURD_THREADVAR_*/_hurd_threadvar_location interface), and directly use __thread instead.

IRC, freenode, #hurd, 2011-10-23

<tschwinge> youpi: If we want to replace threadvars with TLS, there is one
  problem: the threadvars interface is publically exported:
  /usr/include/hurd/threadvar.h.
<tschwinge> youpi: But I am somewhat inclined to say that the only user of
  this is libthreads/libpthread.  Do you think differently?
<youpi> tschwinge: that's very probable
<youpi> so I think we can just drop it
<youpi> (people should use TLS anyway)

libpthread set stack size.

After this has been done, probably the whole __libc_tsd_* stuff can be dropped altogether, and __thread directly be used in glibc.

IRC, freenode, #hurd, 2012-08-07

<tschwinge> r5219: Update libpthread patch to replace threadvar with tls
  for pthread_self
<tschwinge> r5224: revert r5219 too, it's not ready either
<youpi> as the changelog says, the __thread revertal is because it posed
  problems
<youpi> and I just didn't have any time to check them while the freeze was
  so close
<tschwinge> OK.  What kind of problems?  Should it be reverted upstream,
  too?
<youpi> I don't remember exactly
<youpi> it should just be fixed
<youpi> we can revert it upstream, but it'd be good that we manage to
  progress, at some point...
<tschwinge> Of course -- however as long as we don't know what kind of
  problem, it is a bit difficult.  ;-)
<youpi> since I didn't left a note, it was most probably a mere glibc run,
  or boot with the patched libpthread
<youpi> *testsuite run
<tschwinge> OK.
<tschwinge> The libpthread testsuite doesn't show any issues with that
  patch applied, though.  But I didn'T test anything else.
<tschwinge> youpi: Also, you have probably seen my glibc __thread errno
  email -- rmcgrath wanted to find some time this week to comment/help, and
  I take it you don't have any immediate comments to that issue?
<youpi> I saw the mails, but didn't investigate at all

id:"878vdyqht3.fsf@kepler.schwinge.homeip.net".

getcontext/setcontext

Needed for gccgo.

Instead of adding support for getcontext/setcontext within the Hurd threadvar context, which might become a bit ugly, the idea is to get rid of Hurd threadvars and replace them with TLS (as we want to, anyway).

IRC, freenode, #hurd, 2012-04-19

<gnu_srs> How much work/knowledge is needed to implement
  getcontext/setcontext?
<gnu_srs> Any already implemented alternatives available?
<youpi> x86 registers knowledge, as well as unix signal masks
<youpi> there's the linux implementation that can be taken as an
  exxample, but the signal part has to be rewritten
<gnu_srs> Well, it's a pity they are not implemented. That's the
  remaining hurdle to get gccgo working :-( 
<youpi> uh :/
<gnu_srs> Everything builds, but the testsuite fails due to these
  missing functions.
<gnu_srs> Regarding getcontext/setcontext they seem to be written
  in assembly for linux but the code is not very long. 
<gnu_srs> How much effort would it be to write something similar
  for Hurd? Anybody fluent in asm?
<gnu_srs> And registers and signals.
<tschwinge> gnu_srs: Signals is the key thing -- everything else we
  can probably just copy.  I have never/not yet looked at it,
  though.
<gnu_srs> For kfreebsd it is written in C: kern_context.c, 3/4 in
  one file: getcontext, setcontext,  swapcontext, not makecontext.
<gnu_srs> Dunno how much assembly calls used though.
<gnu_srs> Hi, any preferences about implementing get/setcontext in
  C or Asm?
<tschwinge> gnu_srs: I think these will have to be implemented in
  assembly.  Based on the Linux x86 variants.

IRC, freenode, #hurd, 2012-04-20

<tschwinge> youpi: Your understanding of that is better than mine
  -- the *context stuff can't be very useful at the moment, because
  when the user changes uc_stack.ss_sp (which the glibc tests are
  doing), we're losing access to the _hurd_threadvars.  Correct?
<tschwinge> At least the getcontext test works, the other get a
  SIGILL.
<tschwinge> others
<tschwinge> _hurd_threadvars issue is just guessing.
<youpi> tschwinge: yes, threadvars are on the stack
<youpi> threadvars is not much code, it should just work, but care
  has to be taken on the libpthread/libthread side, which does some
  initialization
<tschwinge> OK, that at least matches my understanding.