Re: [GIT, RFC] Killing the Big Kernel Lock

From: Frederic Weisbecker
Date: Sun Mar 28 2010 - 16:15:24 EST


On Sun, Mar 28, 2010 at 09:05:50PM +0100, Arnd Bergmann wrote:
> > General thoughts:
> >
> > ".llseek = NULL," so far meant "do the Right Thing on lseek() and
> > friends, as far as the fs core can tell". Shouldn't we keep it that
> > way? It's as close to other ".method = NULL," as it can get, which
> > either mean "silently skip this method if it doesn't matter" (e.g.
> > .flush) or "fail attempts to use this method with a fitting errno" (e.g.
> > .write).
>
> My series changes the default from 'default_llseek' to 'generic_file_llseek',
> which is almost identical, except for taking the inode mutex instead of the
> BKL.


What if another file operation changes the file pointer while holding the bkl?
You're not protected anymore in this case.

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