Re: Q: schedule() and implied barriers on arm64

From: Ingo Molnar
Date: Mon Oct 19 2015 - 03:06:40 EST



* Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> In any case, its all moot now, since Paul no longer requires schedule() to imply
> a full barrier.
>
> [...]

Nevertheless from a least-surprise POV it might be worth guaranteeing it, because
I bet there's tons of code that assumes that schedule() is a heavy operation and
it's such an easy mistake to make. Since we are so close to having that guarantee,
we might as well codify it?

Just like system calls are assumed to be barriers in general - and system calls
are more lightweight than schedule() ...

Thanks,

Ingo
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