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Date: Fri, 13 Sep 2013 21:23:26 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        linux-next <linux-next@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Dave Chinner <dchinner@redhat.com>, Glauber Costa <glommer@openvz.org>
Subject: Re: linux-next: manual merge of the akpm tree with Linus' tree
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On Fri, Sep 13, 2013 at 09:18:03PM +0100, Al Viro wrote:
> On Fri, Sep 13, 2013 at 09:00:00PM +0100, Al Viro wrote:
> > >  - d_lru_shrink_move: move from the "global" lru list to a private shrinker list
> > >  - d_shrink_add/del: fairly obvious.
> > > 
> > > And then "denty_lru_add/del" that actually take the current state into
> > > account and do the right thing. Those we had before, I'm just
> > > explaining the difference from the low-level operations that have
> > > fixed "from this state to that" semantics
> > 
> > Looks sane; FWIW, the variant I'm playing with uses two independent
> > flags for "shrinker" and "per-sb", but AFAICS that doesn't yield better
> > code.
> 
> Actually, it does yield slightly better code...  Look - if you take your
> patch and replace LRU_LIST | SHRINK_LIST combination with bare SHRINK_LIST
> (which can't occur right now).  Then all transitions turn into flipping
				       ^^^
> a single bit,

Obviously not *and* lru->shrink is common ;-/  Anyway, any benefit from
microoptimizing that will drown in noise, so... nevermind that idea.