Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Sat, 25 Jul 2015 14:12:46 +0200
From: Jens Gustedt <jens.gustedt@...ia.fr>
To: musl@...ts.openwall.com
Subject: Re: implement stdatomic.h library interface

Hello,

Am Samstag, den 25.07.2015, 11:17 +0200 schrieb Joakim Sindholt:
> On Sat, 2015-07-25 at 08:33 +0200, Jens Gustedt wrote:
> > clang relies on the C library (it seems on bsd) or a gcc installation
> > as a fallback.
> 
> I'm not sure what you mean by this. Can you clarify? Compiler-rt has all
> of clang's own fallback symbols and it looks like they're incompatible
> with libatomic.
> 
> As far as I can tell they just use regular spinlocks on linux without
> any libc dependency what-so-ever and on FreeBSD it goes straight to
> _umtx_op which looks like their version of futex.

so I must have read some obsolete documentation somewhere

In any case a lock with kernel support seems to be preferable. I have
a test application that wildly allocates and deallocates list elements
and inserts them atomically. When there is a 16 byte atomic all is
done with that, if not the lockfull replacement is used. For the
lockfull version I seem to get 3 times more work done when using
LOCK/UNLOCK over just using a spinlock.

Jens


-- 
:: INRIA Nancy Grand Est ::: Camus ::::::: ICube/ICPS :::
:: ::::::::::::::: office Strasbourg : +33 368854536   ::
:: :::::::::::::::::::::: gsm France : +33 651400183   ::
:: ::::::::::::::: gsm international : +49 15737185122 ::
:: http://icube-icps.unistra.fr/index.php/Jens_Gustedt ::




Download attachment "signature.asc" of type "application/pgp-signature" (182 bytes)

Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.