From: Rich Felker <dalias@libc.org>
To: musl@lists.openwall.com
Subject: Re: atomic.h cleanup
Date: Thu, 14 Jan 2016 18:32:24 -0500 [thread overview]
Message-ID: <20160114233223.GA238@brightrain.aerifal.cx> (raw)
In-Reply-To: <1452811068.5797.9.camel@inria.fr>
On Thu, Jan 14, 2016 at 11:37:48PM +0100, Jens Gustedt wrote:
> Am Donnerstag, den 14.01.2016, 17:12 -0500 schrieb Rich Felker:
> > There are already multiple reasons we don't use the compiler's
> > atomics, either directly or indirectly via stdatomic.h. They're not
> > supported in some old/alternative compilers, they generate highly
> > suboptimal code even on modern compilers for some important archs
> > (e.g. ARM),
>
> I have seen some pretty good assembler when using the
> __atomic... builtins, so I can't completely follow, here.
It generates "dmb sy" all over the place instead of "dmb ish".
Synchronizing with external bus devices is NOT something you want to
happen in thread synchronization primitives.
Rich
next prev parent reply other threads:[~2016-01-14 23:32 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-10 12:21 Markus Wichmann
2016-01-10 16:57 ` Rich Felker
2016-01-10 17:35 ` Markus Wichmann
2016-01-10 17:50 ` Alexander Monakov
2016-01-11 16:35 ` Markus Wichmann
2016-01-11 17:12 ` Jens Gustedt
2016-01-11 19:03 ` Szabolcs Nagy
2016-01-11 20:56 ` Jens Gustedt
2016-01-14 22:12 ` Rich Felker
2016-01-14 22:37 ` Jens Gustedt
2016-01-14 23:32 ` Rich Felker [this message]
2016-01-15 0:46 ` Szabolcs Nagy
2016-01-10 17:37 ` Markus Wichmann
2016-01-22 0:09 ` Rich Felker
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