Re: [announce] "kill the Big Kernel Lock (BKL)" tree

From: Jonathan Corbet
Date: Wed May 14 2008 - 18:07:57 EST


Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:

> I don't think there are *that* many. I found only 83 instances of
> "register_chrdev()" in the kernel, so the open methods should be pretty
> limited.

There's the drivers calling cdev_add() directly as well - another
40ish. Still not a huge list, I guess.

> So it literally should be:
> - remove one lock_kernel/unlock_kernel pair in fs/char_dev.c
> - add max 83 pairs in the places that register those things
> - external modules will need to add it themselves some day.

This is all certainly doable, but it leaves me with one concern: there
will be no signal to external module maintainers that the change needs
to be made. So, beyond doubt, quite a few of them will just continue to
be shipped unfixed - and they will still run. If any of them actually
*need* the BKL, something awful may happen to somebody someday.

jon
--
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/