Re: [PATCH] Use IE model for static variables in glibc

[Roland McGrath <roland at hack dot frob dot com>]

> I'll need to ensure that test cases are not built with
> -ftls-model=initial-exec and also specific cases like memusage.

Right.

> Basically, it is more work and is probably not something I can finish
> in time for 2.22, given that I have other stuff to finish in the near
> term.  I'll add the readelf test case now to ensure that all libc.so
> and libpthread.so code is IE.  I've not reviewed the other modules and
> I suspect that some of them should not have it either.  Do you think
> it would be OK if I do this in 2.23?

If we have the readelf test in then I think that's fine for the time being.
Cleaning up further is just an ease-of-maintenance issue.  The test will
break when such maintenance is required, so worst case we won't actually
revisit the issue until that happens.

> I also have to look at the impact on ARM since it uses -ftls-model=gnu2
> to get tls descriptors.  I reckon it would actually be an improvement,
> but I'd like to make sure that it is.

Fair enough.

> There's also a good case IMO to somehow compute static TLS usage within
> libc.so and libpthread.so and add that to the surplus.  That way the
> surplus would be reserved specifically for user DSOs that absolutely want
> to use IE and libc will never encroach that.  Again a good project for
> 2.23.

That sounds reasonable.


Thanks,
Roland