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Date:   Thu, 22 Dec 2022 12:44:12 +0000
From:   Mel Gorman <mgorman@techsingularity.net>
To:     Yang Shi <shy828301@gmail.com>
Cc:     Lorenzo Stoakes <lstoakes@gmail.com>,
        Matthew Wilcox <willy@infradead.org>, linux-mm@kvack.org,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Ingo Molnar <mingo@kernel.org>, Marco Elver <elver@google.com>,
        Michal Hocko <mhocko@suse.com>
Subject: Re: [PATCH] mm: remove unused alloc_pages_bulk_list()
Message-ID: <20221222124412.rpnl2vojnx7izoow@techsingularity.net>
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 <20221219100734.jag6zejp4tug77yq@techsingularity.net>
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On Tue, Dec 20, 2022 at 09:56:19AM -0800, Yang Shi wrote:
> On Mon, Dec 19, 2022 at 2:07 AM Mel Gorman <mgorman@techsingularity.net> wrote:
> >
> > On Sat, Dec 17, 2022 at 08:34:58AM +0000, Lorenzo Stoakes wrote:
> > > + Mel
> > >
> > > On Sat, Dec 17, 2022 at 04:56:03AM +0000, Matthew Wilcox wrote:
> > > > I think we're waiting to see if any users show up.  It's only been 18
> > > > months or so, so perhaps wait a little longer?
> > >
> > > Apologies, I should have researched the background of this further. I see it was
> > > added speculatively in 0f87d9d30f.
> > >
> > > > Also, if we do get rid of this, then __alloc_pages_bulk() can lose
> > > > the "list" argument.
> > >
> > > Ack. Will do a v2 if Mel feels it's appropriate to remove at this stage,
> > > otherwise we can drop the idea and wait for users to emerge.
> >
> > I reckon we should give it another few months until May. There has been
> > one user recently that tried to use list but it turned out arrays were
> > more appropriate.
> 
> Another recent try was the patches for dm-crypt. However Mel suggested
> adding a callback interface instead of using list since list is not
> necessary for that usecase. Or are we talking about the same one?
> 

That was the one I was thinking of but forgot the specifics so the array
comment was wrong. I only remembered that there was an attempted list user
but it wasn't the best solution.

> I didn't get time to implement Mel's suggestion yet due to my
> employment change. Hopefully I can find some time after the new year.
> 

No rush.

-- 
Mel Gorman
SUSE Labs