Re: KCSAN: data-race in __alloc_file / __alloc_file

[Linus Torvalds]

On Sun, Nov 10, 2019 at 12:44 PM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:
>
> But will "one size fits all" be practical and useful?

Oh, I do agree that if KCSAN has some mode where it says "I'll ignore
repeated writes with the same value" (or whatever), it could/should
likely be behind some flag.

I don't think it should be a subsystem flag, though. More of a "I'm
willing to actually analyze and ignore false positives" flag. Because
I don't think it's so much about the code, as it is about the person
who looks at the results.

For example, we're already getting push-back from people on some of
the KCSAN-inspired patches. If we have people sending patches to add
READ_ONCE/WRITE_ONCE to random places to shut up KCSAN reports, I
don't think that's good.

But if we have people who _work_ on memory ordering issues etc, and
want to see a strict mode, knowing there are false positives and able
to handle them, that's a completely different thing..

No?

              Linus