The riddle of atomic data transfer from process A to process B

[Baruch Siach]

Hi Omer,

On Wed, Apr 13, 2011 at 04:07:42PM +0300, Omer Zak wrote:
> The system has several such processes, so it is desirable to have an
> inter-process mechanism having the absolute minimum overhead for
> unidirectional data transfers from measuring processes (like process M)
> to action taking processes (such as process A).

[snip]

> The riddle:
> 1. If the operating system being used is Linux, what other mechanisms
> (besides turning off interrupts) are available to single-processor
> systems to accomplish this?
> 2. If the system has a multi-core processor or several processors, which
> low overhead synchronization method can be used to accomplish this?

You may try the Userspace RCU library, http://lttng.org/urcu. See also 
http://lwn.net/Articles/369567/ for a discussion about optimizing the 
expensive memory barriers.

baruch

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