From: Rich Felker <dalias@aerifal.cx>
To: musl@lists.openwall.com
Subject: Re: TLS (thread-local storage) support
Date: Tue, 16 Oct 2012 21:58:42 -0400 [thread overview]
Message-ID: <20121017015842.GX254@brightrain.aerifal.cx> (raw)
In-Reply-To: <CAKAk8dYzbdNf-B3JHyM+yrFPB_kM1MkyP+5sEAJ6kDO17GcFdw@mail.gmail.com>
On Wed, Oct 17, 2012 at 03:49:33AM +0200, boris brezillon wrote:
> 2012/10/17 Rich Felker <dalias@aerifal.cx>:
> > On Wed, Oct 17, 2012 at 02:08:11AM +0200, boris brezillon wrote:
> >> >> I agree. This should be made optional. But if we don't compile libc
> >> >> with fsplit-stack (-fnosplit-stack).
> >> >> Each call to a libc func from an external func compiled with split
> >> >> stack may lead to a 64K stack chunk alloc.
> >> >
> >> > Where does this allocation take place from? There should simply be a
> >> > way to inhibit it.
> >> In the linker (gold linker).
> >
> > Well gold isn't running at runtime. I assume you mean it _arranges_
> > for this allocation to take place somehow, and that's what I'm
> > wondering about whether there's a way to avoid.
>
> The easiest way to avoid big stack chunk allocation is to compile musl
> with -fno-split-stack option.
> This will not add any overhead to functions (no split stack prolog)
> And this will add a note to the shared object which tells the linker
> to avoid __morestack to __morestack_non_split replacement.
Where is this documented? The GCC manual doesn't mention anything
about -fno-split-stack having special behavior like that, so for lack
of any documentation otherwise, it "should" just be the option to turn
off -fsplit-stack..
I'm not claiming you're wrong, just that this all seems poorly
documented.
Rich
next prev parent reply other threads:[~2012-10-17 1:58 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-04 21:13 Rich Felker
2012-10-04 21:29 ` Daniel Cegiełka
2012-10-04 22:36 ` Rich Felker
2012-10-06 8:17 ` Daniel Cegiełka
2012-10-16 21:27 ` boris brezillon
2012-10-16 21:47 ` boris brezillon
2012-10-16 22:09 ` Szabolcs Nagy
2012-10-16 23:16 ` boris brezillon
2012-10-17 10:37 ` Szabolcs Nagy
2012-10-16 23:29 ` Rich Felker
2012-10-16 22:54 ` Rich Felker
2012-10-16 23:39 ` boris brezillon
2012-10-16 23:48 ` Rich Felker
2012-10-17 0:08 ` boris brezillon
2012-10-17 0:42 ` Rich Felker
2012-10-17 1:03 ` boris brezillon
2012-10-17 1:49 ` boris brezillon
2012-10-17 1:58 ` Rich Felker [this message]
2012-10-17 7:48 ` musl
2012-10-19 18:39 ` orc
2012-10-19 18:41 ` Rich Felker
2012-10-05 3:04 ` Rich Felker
2012-10-05 17:27 ` Rich Felker
2012-10-06 14:33 ` Szabolcs Nagy
2012-10-06 20:39 ` Szabolcs Nagy
2012-10-06 20:58 ` Rich Felker
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