Re: patches for test-and-set without ll/sc (Re: thread-ready ABIs)

Re: patches for test-and-set without ll/sc (Re: thread-ready ABIs)

[Ulrich Drepper]

Machida Hiroyuki <machida@sm.sony.co.jp> writes:

>   * glibc change:
> 
> 	We implement  test_and_set(addr, val) as follows,
> 
> 		Do mmap /dev/tst to _TST_START_MAGIC, if not yet mapped.
> 		call _TST_START_MAGIC(addr, val)
> 	
> 	If we can't open /dev/tst then, use sysmips() as final resort.

First, the patch as it is unacceptable.  A file with copyright Sony?
All the code must be copyrighted by the FSF.  Sony will have to assign
the copyright for the code to the FSF.

Also, no such change can be accepted until the necessary kernel
changes are in the official kernel sources.  I cannot make any
exceptions since otherwise all kinds of people want to see support for
their local hack added.

Furthermore, the symbols were not available in version 2.2.  Therefore
they cannot be exported with this version.  It'll either be 2.2.6 (if
their ever will be such a release) or 2.3.

And finally, the patch should be sent to the glibc MIPS maintainer for
review.  The question is who feels responsible...

-- 
---------------.                          ,-.   1325 Chesapeake Terrace
Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
Red Hat          `--' drepper at redhat.com   `------------------------

Re: patches for test-and-set without ll/sc (Re: thread-ready ABIs)

[Ulrich Drepper]

Machida Hiroyuki <machida@sm.sony.co.jp> writes:

> Please let us why. Acctually, glibc includes codes copyrighted by
> SUN and gcc includes codes copryrighed by HP and SGI.

It contains public domain code and the rest of the code is assigned.
If there is a header saying that somebody from a company wrote the
code this is mentioned but the person also has a document signed.

If you cannot live with this the code cannot be accepted.  Any further
discussion you have to have with the legal people at the FSF.  I've no
time for this.

-- 
---------------.                          ,-.   1325 Chesapeake Terrace
Ulrich Drepper  \    ,-------------------'   \  Sunnyvale, CA 94089 USA
Red Hat          `--' drepper at redhat.com   `------------------------

Re: patches for test-and-set without ll/sc (Re: thread-ready ABIs)

[Andreas Jaeger]

Ulrich Drepper <drepper@redhat.com> writes:

> Machida Hiroyuki <machida@sm.sony.co.jp> writes:
>
>>   * glibc change:
>> 
>> 	We implement  test_and_set(addr, val) as follows,
>> 
>> 		Do mmap /dev/tst to _TST_START_MAGIC, if not yet mapped.
>> 		call _TST_START_MAGIC(addr, val)
>> 	
>> 	If we can't open /dev/tst then, use sysmips() as final resort.
>
> First, the patch as it is unacceptable.  A file with copyright Sony?
> All the code must be copyrighted by the FSF.  Sony will have to assign
> the copyright for the code to the FSF.
>
> Also, no such change can be accepted until the necessary kernel
> changes are in the official kernel sources.  I cannot make any
> exceptions since otherwise all kinds of people want to see support for
> their local hack added.
>
> Furthermore, the symbols were not available in version 2.2.  Therefore
> they cannot be exported with this version.  It'll either be 2.2.6 (if
> their ever will be such a release) or 2.3.
>
> And finally, the patch should be sent to the glibc MIPS maintainer for
> review.  The question is who feels responsible...

I'll look into it later in more detail.

But for now, let me just tell that I agree with Ulrich's comments.
Additionally I'd like to wait with adding this patch until:
- a solution for the thread register is found for MIPS (and those
  solution should not conflict with this patch)
- the kernel side patches have been adopted.

Therefore please discuss this with the kernel and ABI folks, and then
let's look again at the issues.

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
    http://www.suse.de/~aj