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Re: Fixing the distribution problems with TLS and DTV_SURPLUS slots.
- From: "Carlos O'Donell" <carlos at redhat dot com>
- To: Alexandre Oliva <aoliva at redhat dot com>
- Cc: GNU C Library <libc-alpha at sourceware dot org>
- Date: Fri, 10 Oct 2014 13:41:55 -0400
- Subject: Re: Fixing the distribution problems with TLS and DTV_SURPLUS slots.
- Authentication-results: sourceware.org; auth=none
- References: <5432EFF9 dot 5020602 at redhat dot com> <orzjd8xv5v dot fsf at free dot home> <5436A03F dot 2050008 at redhat dot com> <or7g089kss dot fsf at free dot home>
On 10/10/2014 08:22 AM, Alexandre Oliva wrote:
>> (a) Immediately increase DTV surplus size.
>> (b) Implement static TLS support without needing a DTV increase.
>> (c) Remove faulty heursitics around not wanting to increase DTV size.
>> (d) Add __attribute__((tls_model("go-fast"))) to gcc that defaults to
>> IE if TLS Desc is not present.
>> (e) Approach upstream projects with patches to convert to TLS descriptors
>> using go-fast model.
>
> Heh. I guess my suggestion is that we go backwards in your list. IE
> abuse is not our bug.
:-)
> (b) requires little more than dropping some incorrect asserts. And once
> we get to that (remember, going backwards), (a) is completely
> unnecessary: why waste per-thread memory for everyone if it's not
> needed?
I've outlined a slightly different path in the other email to Rich.
See if you like that set of steps better.
Cheers,
Carlos.