Re: Efficient IPC mechanism on Linux

[Luca Veraldi]

> I'm saying it can. I don't want to go too deep into an arguement about
> microarchitectural details, but my point was that a memory copy of a page
> is NOT super expensive relative to several other effects that have to do
> with pagetable manipulations.

Sorry, but I cannot believe it.
Reading a page tagle entry and storing in into a struct capability is not
comparable at all with the "for" needed to move bytes all around memory.

> but the pipe code cannot know this so it has to do a cross cpu invalidate.

Sorry for you. Don't knowning does not justify it.
It's inefficient.

> and... which is also releasing it before the copy

Oh, yes. After wasting thousands of cycles, sure.

Bye,
Luca.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/