Messages in this thread | | | Subject | Re: [Linux-kernel-mentees][PATCH v6 1/2] sgi-gru: Convert put_page() to put_user_page*() | From | John Hubbard <> | Date | Mon, 19 Aug 2019 12:30:18 -0700 |
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On 8/19/19 12:06 PM, Bharath Vedartham wrote: > On Mon, Aug 19, 2019 at 07:56:11AM -0500, Dimitri Sivanich wrote: >> Reviewed-by: Dimitri Sivanich <sivanich@hpe.com> > Thanks! > > John, would you like to take this patch into your miscellaneous > conversions patch set? >
(+Andrew and Michal, so they know where all this is going.)
Sure, although that conversion series [1] is on a brief hold, because there are additional conversions desired, and the API is still under discussion. Also, reading between the lines of Michal's response [2] about it, I think people would prefer that the next revision include the following, for each conversion site:
Conversion of gup/put_page sites:
Before:
get_user_pages(...); ... for each page: put_page();
After:
gup_flags |= FOLL_PIN; (maybe FOLL_LONGTERM in some cases) vaddr_pin_user_pages(...gup_flags...) ... vaddr_unpin_user_pages(); /* which invokes put_user_page() */
Fortunately, it's not harmful for the simpler conversion from put_page() to put_user_page() to happen first, and in fact those have usually led to simplifications, paving the way to make it easier to call vaddr_unpin_user_pages(), once it's ready. (And showing exactly what to convert, too.)
So for now, I'm going to just build on top of Ira's tree, and once the vaddr*() API settles down, I'll send out an updated series that attempts to include the reviews and ACKs so far (I'll have to review them, but make a note that review or ACK was done for part of the conversion), and adds the additional gup(FOLL_PIN), and uses vaddr*() wrappers instead of gup/pup.
[1] https://lore.kernel.org/r/20190807013340.9706-1-jhubbard@nvidia.com
[2] https://lore.kernel.org/r/20190809175210.GR18351@dhcp22.suse.cz
thanks, -- John Hubbard NVIDIA
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