Re: [PATCH] Document Linux's memory barriers [try #4]

From: Eric W. Biederman
Date: Sun Mar 12 2006 - 12:14:30 EST



A small nit. You are not documenting the most subtle memory barrier:
smp_read_barrier_depends(); Which is a deep requirement of the RCU
code.

As I understand it. On some architectures (alpha) without at least
this a load from a pointer can load from the an old pointer value.

At one point it was suggested this be called:
read_memory_barrier_data_dependent().

Simply calling: rcu_dereference is what all users should call but
the semantics should be documented at least so that people porting
Linux can have a chance of getting it right.

Eric
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