From mboxrd@z Thu Jan 1 00:00:00 1970 From: mhocko at kernel.org (Michal Hocko) Date: Tue, 20 Aug 2019 10:18:20 +0200 Subject: [Linux-kernel-mentees] [PATCH v6 1/2] sgi-gru: Convert put_page() to put_user_page*() In-Reply-To: <0c2ad29b-934c-ec30-66c3-b153baf1fba5@nvidia.com> References: <1566157135-9423-1-git-send-email-linux.bhar@gmail.com> <1566157135-9423-2-git-send-email-linux.bhar@gmail.com> <20190819125611.GA5808@hpe.com> <20190819190647.GA6261@bharath12345-Inspiron-5559> <0c2ad29b-934c-ec30-66c3-b153baf1fba5@nvidia.com> Message-ID: <20190820081820.GI3111@dhcp22.suse.cz> List-Id: On Mon 19-08-19 12:30:18, John Hubbard wrote: > 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 > > 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...) I was hoping that FOLL_PIN would be handled by vaddr_pin_user_pages. > ... > 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.) If that makes the later conversion easier then no real objections from me. Assuming that the current put_user_page conversions are correct of course (I have the mlock one and potentials that falls into the same category in mind). -- Michal Hocko SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 From: mhocko@kernel.org (Michal Hocko) Date: Tue, 20 Aug 2019 10:18:20 +0200 Subject: [Linux-kernel-mentees] [PATCH v6 1/2] sgi-gru: Convert put_page() to put_user_page*() In-Reply-To: <0c2ad29b-934c-ec30-66c3-b153baf1fba5@nvidia.com> References: <1566157135-9423-1-git-send-email-linux.bhar@gmail.com> <1566157135-9423-2-git-send-email-linux.bhar@gmail.com> <20190819125611.GA5808@hpe.com> <20190819190647.GA6261@bharath12345-Inspiron-5559> <0c2ad29b-934c-ec30-66c3-b153baf1fba5@nvidia.com> Message-ID: <20190820081820.GI3111@dhcp22.suse.cz> List-Id: Content-Type: text/plain; charset="UTF-8" Message-ID: <20190820081820.nFFHXMM59gPvTzUU4S_-bnvkrmGku0mNAJfMkUg8gr0@z> On Mon 19-08-19 12:30:18, John Hubbard wrote: > 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 > > 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...) I was hoping that FOLL_PIN would be handled by vaddr_pin_user_pages. > ... > 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.) If that makes the later conversion easier then no real objections from me. Assuming that the current put_user_page conversions are correct of course (I have the mlock one and potentials that falls into the same category in mind). -- Michal Hocko SUSE Labs