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Re: TLS redux
- From: Alexander Monakov <amonakov at ispras dot ru>
- To: Carlos O'Donell <carlos at redhat dot com>
- Cc: Rich Felker <dalias at aerifal dot cx>, Jason Evans <jasone at canonware dot com>, Paul Pluzhnikov <ppluzhnikov at google dot com>, Andreas Schwab <schwab at linux-m68k dot org>, "Joseph S. Myers" <joseph at codesourcery dot com>, Roland McGrath <roland at hack dot frob dot com>, "GNU C. Library" <libc-alpha at sourceware dot org>, Will Newton <will dot newton at linaro dot org>
- Date: Thu, 30 Jan 2014 14:21:07 +0400 (MSK)
- Subject: Re: TLS redux
- Authentication-results: sourceware.org; auth=none
- References: <20140115022335 dot EB13174430 at topped-with-meat dot com> <Pine dot LNX dot 4 dot 64 dot 1401150520530 dot 14350 at digraph dot polyomino dot org dot uk> <CALoOobOyQxDaszErqoOkSdHsc7NestF7Pt9rS01aPzWZcnFZCQ at mail dot gmail dot com> <87r47tz5xd dot fsf at igel dot home> <CALoOobNZVFQ7z0uOgp6zAKMk7fmx03ua6S5E24UNgtVM3o=etQ at mail dot gmail dot com> <61CF7641-148C-4D7B-BE80-A1E3CC0AA498 at canonware dot com> <20140129012316 dot GM24286 at brightrain dot aerifal dot cx> <52E9E6FB dot 5010706 at redhat dot com>
On Thu, 30 Jan 2014, Carlos O'Donell wrote:
> On 01/28/2014 08:23 PM, Rich Felker wrote:
> >
> > Yet another reason that failing to save/restore the FULL register set
> > on lazy symbol resolution is a bug that should be fixed on all archs,
> > rather than being swept under the rug with excuses.
>
> Do we have a bugzilla entry for this?
For one aspect of the problem, https://sourceware.org/bugzilla/show_bug.cgi?id=15786
> I can tag it for 2.20 and see if we can fix this.
>
> The consequences seem somewhat dire though for performance?
I don't understand why you say so. I'd say the amount of work to save a few
additional registers is a drop in the ocean compared to the amount of work in
symbol resolution.
> Could we just do the save/restore around malloc at least?
>
> I thought we ran into a similar bug for ARM and NEON?
https://sourceware.org/bugzilla/show_bug.cgi?id=15128
Alexander