Re: [PATCH 06/17] fs: icache lock lru/writeback lists

From: Dave Chinner
Date: Thu Sep 30 2010 - 02:16:49 EST


On Wed, Sep 29, 2010 at 09:52:40PM -0700, Andrew Morton wrote:
> On Wed, 29 Sep 2010 22:18:38 +1000 Dave Chinner <david@xxxxxxxxxxxxx> wrote:
>
> > The inode moves between different lists protected by the inode_lock. Introduce
> > a new lock that protects all of the lists (dirty, unused, in use, etc) that the
> > inode will move around as it changes state. As this is mostly a list for
> > protecting the writeback lists, name it wb_inode_list_lock and nest all the
> > list manipulations in this lock inside the current inode_lock scope.
>
> All those spin_trylock()s are real ugly. They're unexplained in the
> changelog and unexplained in code comments.

Yes, they are, but I don't know exactly why it is so trylock happy.
I'll try to dig out the reason for it and:

> I'd suggest that each such site have a comment explaining why we're
> resorting to this.

At least get this far.

Cheers,

Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
--
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/