Re: Implementation of lock-free atomics on m68k
On 12/18/2016 02:02 PM, Andreas Schwab wrote:
>> I knew m68k has CAS/CAS2, but my suspicion was that lock-free atomics
>> require LDREX/STREX-alike instructions since older ARM implementations
>> have SWP/SWPB as well. So it shouldn't be too different from the CAS
>> instructions on m68k, should it?
>
> SWP is UP-only, and armv8 doesn't implement it.
I think the main problem with SWP/SWPB is that they don't allow to implement
real lock-free atomics, isn't it? [1]
I'm just trying to figure out whether there is a way I can help the Debian
armel porters to get lock-free atomics in the toolchain so they can have
full C++11 support including std::future, possibly with the help of
existing kernel helper functions.
Adrian
> [1] http://infocenter.arm.com/help/topic/com.arm.doc.dht0008a/DHT0008A_arm_synchronization_primitives.pdf
--
.''`. John Paul Adrian Glaubitz
: :' : Debian Developer - glaubitz@debian.org
`. `' Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
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