Re: [RFC PATCH 1/8] Convert the RCU tasklet into a softirq

On Mon, 16 Jul 2007, Linus Torvalds wrote:

>
> Btw, are there any numbers on this? Is this whole thing actually
> noticeable?

Besides the obvious removal of code?

The old way actually made an effort to create per_cpu tasklets!  So that
the tasklets *can* run simultaneously, making it in essense a softirq.
Since tasklets are implemented by the softirq, with a lot of code to make
a tasklet function run only on one CPU at a time, and it can run on any
CPU.  By converting the rcu tasklet (which had work to make it act like a
softirq) to just be a softirq, we removed all the extra overhead of a
tasklet.

But to answer your question.  No, I didn't take any actual measurements.
The changes just seemed obvious to me (and others).

-- Steve

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