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Date:   Wed, 6 Nov 2019 18:25:08 -0800
From:   Ira Weiny <ira.weiny@intel.com>
To:     John Hubbard <jhubbard@nvidia.com>
Cc:     Mike Rapoport <rppt@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
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Subject: Re: [PATCH v2 05/18] mm/gup: introduce pin_user_pages*() and FOLL_PIN
Message-ID: <20191107022508.GB32084@iweiny-DESK2.sc.intel.com>
References: <20191103211813.213227-1-jhubbard@nvidia.com>
 <20191103211813.213227-6-jhubbard@nvidia.com>
 <20191105131032.GG25005@rapoport-lnx>
 <9ac948a4-59bf-2427-2007-e460aad2848a@nvidia.com>
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> 
> 
> ...
> >> +This document describes the following functions: ::
> >> +
> >> + pin_user_pages
> >> + pin_user_pages_fast
> >> + pin_user_pages_remote
> >> +
> >> + pin_longterm_pages
> >> + pin_longterm_pages_fast
> >> + pin_longterm_pages_remote
> >> +
> >> +Basic description of FOLL_PIN
> >> +=============================
> >> +
> >> +A new flag for get_user_pages ("gup") has been added: FOLL_PIN. FOLL_PIN has
> > 
> > Consider reading this after, say, half a year ;-)
> > 
> 
> OK, OK. I knew when I wrote that that it was not going to stay new forever, but
> somehow failed to write the right thing anyway. :) 
> 
> Here's a revised set of paragraphs:
> 
> Basic description of FOLL_PIN
> =============================
> 
> FOLL_PIN and FOLL_LONGTERM are flags that can be passed to the get_user_pages*()
> ("gup") family of functions. FOLL_PIN has significant interactions and
> interdependencies with FOLL_LONGTERM, so both are covered here.
> 
> Both FOLL_PIN and FOLL_LONGTERM are internal to gup, meaning that neither
> FOLL_PIN nor FOLL_LONGTERM should not appear at the gup call sites. This allows
> the associated wrapper functions  (pin_user_pages() and others) to set the
> correct combination of these flags, and to check for problems as well.

I like this revision as well.

Ira