From: Florian Weimer <fweimer@redhat.com>
To: Carlos O'Donell <codonell@redhat.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>,
nd@arm.com, GNU C Library <libc-alpha@sourceware.org>
Subject: Re: [PATCH] Reserve static TLS for dynamically loaded initial-exec TLS only [BZ #25051]
Date: Mon, 17 Feb 2020 17:01:54 +0100 [thread overview]
Message-ID: <87k14lmcct.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <5474f68c-b093-8791-ca0b-b4b715174e2c@redhat.com> (Carlos O'Donell's message of "Thu, 13 Feb 2020 13:07:56 -0500")
* Carlos O'Donell:
> Let me take a stab at this:
>
> (1) File a bug to indicate all libraries must stop using
> TLS IE to fix dlmopen issues with TLS IE.
Do you mean glibc components, or do you view this as a distribution-wide
change?
> (2) Set DL_NNS to 4, and add a tunable that lets you change
> the limit to reduce surplus memory allocated.
>
> (2.a) send linux man-pages a patch to make dlmopen(3)
> ambiguous about how many namespaces are supported and
> to point at the tunable to increase the memory used.
>
> (3) I think that the surplus should be split into two
> blocks:
> (3.a) Some reserved for TLS IE libs.
> (3.b) Some reserved for tlsdesc optimization.
>
> My opinion is that any library that is loaded and
> needs TLS IE should be able to use (3.a). We should
> reserve enough for (3.a) to be able to load glibc
> libraries, libgomp, and libgl (as you note).
There's also a potential for not letting audit libraries consume
namespace slots (once they are dynamic). This will enable lower DL_NNS
defaults.
Thanks,
Florian
next prev parent reply other threads:[~2020-02-17 16:02 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-07 11:54 [PATCH] Reserve static TLS for dynamically loaded initial-exec TLS only [BZ #25051] Szabolcs Nagy
2020-01-07 12:09 ` Florian Weimer
2020-01-07 12:50 ` Szabolcs Nagy
2020-02-13 16:38 ` Szabolcs Nagy
2020-02-13 18:07 ` Carlos O'Donell
2020-02-17 16:01 ` Florian Weimer [this message]
2020-02-20 15:05 ` Carlos O'Donell
2020-02-21 12:58 ` Florian Weimer
2020-02-27 16:21 ` Szabolcs Nagy
2020-02-27 16:31 ` Florian Weimer
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