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b=xB+VYKK0H/52HtA7kk4kkDuLORROCD0C2M/fV6CB4n4vuu8XaH4BeP8fZ2Pp4J5njvAHlG /lGw1IPf6OAVlqI4mLWHvQ5PU1pXQQqC3NuEeHweQ580x+r1qtRrQvOvpxfOKTwCDMtJUx z4Qezyoy0gmM58jSO679SwmTSPf3HTk= X-Rspam-User: X-Stat-Signature: uzt9ui73yc7dk944yx6d5hfi4cazt9i1 X-Rspamd-Queue-Id: 307914012D Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b="sBa/K0CS"; spf=pass (imf27.hostedemail.com: domain of jhubbard@nvidia.com designates 40.107.93.54 as permitted sender) smtp.mailfrom=jhubbard@nvidia.com; arc=pass ("microsoft.com:s=arcselector9901:i=1"); dmarc=pass (policy=reject) header.from=nvidia.com X-Rspamd-Server: rspam02 X-HE-Tag: 1659684913-483915 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 8/4/22 23:29, Alistair Popple wrote: > gup_flags is passed to check_and_migrate_movable_pages() so that it can > call either put_page() or unpin_user_page() to drop the page reference. > However check_and_migrate_movable_pages() is only called for > FOLL_LONGTERM, which implies FOLL_PIN so there is no need to pass heh, while verifying the above claim, I noticed that __gup_longterm_locked() has been misnamed for some time now. That function handles both FOLL_LONGTERM and !FOLL_LONGTERM. There's always something... Anyway, though, this patch is a good cleanup step, so: Reviewed-by: John Hubbard thanks, -- John Hubbard NVIDIA > gup_flags. > > Signed-off-by: Alistair Popple > --- > mm/gup.c | 21 ++++++++------------- > 1 file changed, 8 insertions(+), 13 deletions(-) > > diff --git a/mm/gup.c b/mm/gup.c > index c6d060d..e26ccc0 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -1907,8 +1907,7 @@ struct page *get_dump_page(unsigned long addr) > * Return negative error if migration fails. > */ > static long check_and_migrate_movable_pages(unsigned long nr_pages, > - struct page **pages, > - unsigned int gup_flags) > + struct page **pages) > { > unsigned long isolation_error_count = 0, i; > struct folio *prev_folio = NULL; > @@ -1941,10 +1940,8 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, > * Migration will fail if the page is pinned, so convert > * the pin on the source page to a normal reference. > */ > - if (gup_flags & FOLL_PIN) { > - get_page(&folio->page); > - unpin_user_page(&folio->page); > - } > + get_page(&folio->page); > + unpin_user_page(&folio->page); > > ret = migrate_device_coherent_page(&folio->page); > if (ret) > @@ -1998,10 +1995,7 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, > if (!pages[i]) > continue; > > - if (gup_flags & FOLL_PIN) > - unpin_user_page(pages[i]); > - else > - put_page(pages[i]); > + unpin_user_page(pages[i]); > } > > if (!list_empty(&movable_page_list)) { > @@ -2023,8 +2017,7 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, > } > #else > static long check_and_migrate_movable_pages(unsigned long nr_pages, > - struct page **pages, > - unsigned int gup_flags) > + struct page **pages) > { > return nr_pages; > } > @@ -2053,7 +2046,9 @@ static long __gup_longterm_locked(struct mm_struct *mm, > NULL, gup_flags); > if (rc <= 0) > break; > - rc = check_and_migrate_movable_pages(rc, pages, gup_flags); > + > + WARN_ON_ONCE(!(gup_flags & FOLL_PIN)); > + rc = check_and_migrate_movable_pages(rc, pages); > } while (!rc); > memalloc_pin_restore(flags); > > > base-commit: 360614c01f81f48a89d8b13f8fa69c3ae0a1f5c7