Messages in this thread | | | Date | Fri, 03 Jul 2009 17:37:31 +0200 | From | Eric Dumazet <> | Subject | Re: [PATCHv5 2/2] memory barrier: adding smp_mb__after_lock |
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Herbert Xu a écrit : > Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote: >> Why don't we create a read_lock without acquire semantic instead (e.g. >> read_lock_nomb(), or something with a better name like __read_lock()) ? >> On architectures where memory barriers are needed to provide the acquire >> semantic, it would be faster to do : >> >> __read_lock(); >> smp_mb(); >> >> than : >> >> read_lock(); <- e.g. lwsync + isync or something like that >> smp_mb(); <- full sync. > > Hmm, why do we even care when read_lock should just die? > > Cheers,
+1 :)
Do you mean using a spinlock instead or what ?
Also, how many arches are able to have a true __read_lock() (or __spin_lock() if that matters), without acquire semantic ? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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