Date: Wed, 12 Apr 2017 09:30:31 -0700
From: Andi Kleen <ak@linux.intel.com>
To: Michal Hocko <mhocko@kernel.org>, Matthew Wilcox <willy@infradead.org>,
        akpm@linux-foundation.org, mtk.manpages@gmail.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, Davidlohr Bueso <dbueso@suse.de>,
        khandual@linux.vnet.ibm.com
Subject: Re: [PATCH] mm,hugetlb: compute page_size_log properly
Message-ID: <20170412163031.GE4021@tassilo.jf.intel.com>
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 <20170328175408.GD7838@bombadil.infradead.org>
 <20170329080625.GC27994@dhcp22.suse.cz>
 <20170329174514.GB4543@tassilo.jf.intel.com>
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On Wed, Apr 12, 2017 at 09:18:29AM -0700, Davidlohr Bueso wrote:
> On Thu, 30 Mar 2017, Michal Hocko wrote:
> 
> > On Wed 29-03-17 10:45:14, Andi Kleen wrote:
> > > On Wed, Mar 29, 2017 at 10:06:25AM +0200, Michal Hocko wrote:
> > > >
> > > > Do we actually have any users?
> > > 
> > > Yes this feature is widely used.
> > 
> > Considering that none of SHM_HUGE* has been exported to the userspace
> > headers all the users would have to use the this flag by the value and I
> > am quite skeptical that application actually do that. Could you point me
> > to some projects that use this?
> 
> Hmm Andrew, if there's not one example, could you please pick up this patch?

?!? We just don't break user ABIs this way in Linux!

Just because you don't like something you cannot simply remove it.

I don't know if there are open source users, but there are known closed
source users for which this was originally implemented.

-Andi