Re: [PATCH -tip] remove the BKL: Replace BKL in mount/umount syscalls with a mutex

[Linus Torvalds <torvalds@linux-foundation.org>]

On Fri, 17 Apr 2009, Jonathan Corbet wrote:

> On Fri, 17 Apr 2009 10:21:06 -0700 (PDT)
> Linus Torvalds <torvalds@linux-foundation.org> wrote:
> 
> > And I know we had patches for file locking BKL-removal at some point. What 
> > happened to them? Were they just broken, or forgotten, or waiting in Jon's 
> > tree, or what?
> 
> Not in my tree, I've not seen them.  I could maybe take a look at that,
> I've just about recovered from my fasync experience...:)

Hmm. It might also just be my fevered imagination. I'd like to say it was 
Matthew Wilcox, but really, my mind is going.

Ahh. Bug google backs me up. As long as I have google, I can keep 
Alzheimer's at bay: "Negative scalability by removal of lock_kernel()" 
thread on lkml back in October 2000. After we had actually done the BKL 
removal.

So we actually did apply it (in 2.4.0-test9, and then reverted it again 
(in -test11, I think). Google for "file_lock_sem fs/locks.c" and see some 
of the discussion. The end result was to go back to the BKL due to Apache 
slowdowns.

But I seem to remember a later patch (in the last year or two) from Willy 
too. Google doesn't help me, so that's probably just my fevered mind. But 
I'm cc'ing Willy anyway.

		Linus