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Subject: Re: [PATCH v4 09/23] mm/gup: introduce pin_user_pages*() and FOLL_PIN
To:     Ira Weiny <ira.weiny@intel.com>
CC:     Andrew Morton <akpm@linux-foundation.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
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References: <20191113042710.3997854-1-jhubbard@nvidia.com>
 <20191113042710.3997854-10-jhubbard@nvidia.com>
 <20191113185902.GB12915@iweiny-DESK2.sc.intel.com>
From:   John Hubbard <jhubbard@nvidia.com>
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On 11/13/19 10:59 AM, Ira Weiny wrote:
> On Tue, Nov 12, 2019 at 08:26:56PM -0800, John Hubbard wrote:
>> Introduce pin_user_pages*() variations of get_user_pages*() calls,
>> and also pin_longterm_pages*() variations.
>>
>> These variants all set FOLL_PIN, which is also introduced, and
>> thoroughly documented.
>>
>> The pin_longterm*() variants also set FOLL_LONGTERM, in addition
>> to FOLL_PIN:
>>
>>      pin_user_pages()
>>      pin_user_pages_remote()
>>      pin_user_pages_fast()
>>
>>      pin_longterm_pages()
>>      pin_longterm_pages_remote()
>>      pin_longterm_pages_fast()
> 
> At some point in this conversation I thought we were going to put in "unpin_*"
> versions of these.
> 
> Is that still in the plans?
> 

Why yes it is! :)  Daniel Vetter and Jan Kara both already weighed in [1],
in favor of "unpin_user_page*()", rather than "put_user_page*()".

I'll change those names.

[1] https://lore.kernel.org/r/20191113101210.GD6367@quack2.suse.cz


thanks,
-- 
John Hubbard
NVIDIA