| Message ID | 20220102215729.2943705-8-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Convert GUP to folios | expand |
On Sun, Jan 02, 2022 at 09:57:19PM +0000, Matthew Wilcox (Oracle) wrote: > put_compound_head() is turned into a call to gup_put_folio(). > This removes the last call to put_page_refs(), so delete it. Except for one more of those nasty page to folio casts (which I assume will go away soon), this looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
On 1/2/22 13:57, Matthew Wilcox (Oracle) wrote: > put_compound_head() is turned into a call to gup_put_folio(). > This removes the last call to put_page_refs(), so delete it. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > mm/gup.c | 44 +++++++++++++++----------------------------- > 1 file changed, 15 insertions(+), 29 deletions(-) > Reviewed-by: John Hubbard <jhubbard@nvidia.com> thanks,
Comment inline. > On Jan 2, 2022, at 2:57 PM, Matthew Wilcox (Oracle) <willy@infradead.org> wrote: > > put_compound_head() is turned into a call to gup_put_folio(). > This removes the last call to put_page_refs(), so delete it. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > mm/gup.c | 44 +++++++++++++++----------------------------- > 1 file changed, 15 insertions(+), 29 deletions(-) > > diff --git a/mm/gup.c b/mm/gup.c > index 58e5cfaaa676..6d827f7d66d8 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -36,29 +36,11 @@ static void folio_pincount_add(struct folio *folio, int refs) > atomic_add(refs, folio_pincount_ptr(folio)); > } > > -static void hpage_pincount_sub(struct page *page, int refs) > +static void folio_pincount_sub(struct folio *folio, int refs) > { > - VM_BUG_ON_PAGE(!hpage_pincount_available(page), page); > - VM_BUG_ON_PAGE(page != compound_head(page), page); > - > - atomic_sub(refs, compound_pincount_ptr(page)); > -} > - > -/* Equivalent to calling put_page() @refs times. */ > -static void put_page_refs(struct page *page, int refs) > -{ > -#ifdef CONFIG_DEBUG_VM > - if (VM_WARN_ON_ONCE_PAGE(page_ref_count(page) < refs, page)) > - return; > -#endif Should this retain a form of the CONFIG_DEBUG_VM warning here to trigger if folio_pincount_ptr(folio) is < refs? > + VM_BUG_ON_FOLIO(!folio_pincount_available(folio), folio); > - /* > - * Calling put_page() for each ref is unnecessarily slow. Only the last > - * ref needs a put_page(). > - */ > - if (refs > 1) > - page_ref_sub(page, refs - 1); > - put_page(page); > + atomic_sub(refs, folio_pincount_ptr(folio)); > } > > /* > @@ -175,19 +157,23 @@ struct page *try_grab_compound_head(struct page *page, > return NULL; > } > > -static void put_compound_head(struct page *page, int refs, unsigned int flags) > +static void gup_put_folio(struct folio *folio, int refs, unsigned int flags) > { > if (flags & FOLL_PIN) { > - mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED, > - refs); > - > - if (hpage_pincount_available(page)) > - hpage_pincount_sub(page, refs); > + node_stat_mod_folio(folio, NR_FOLL_PIN_RELEASED, refs); > + if (folio_pincount_available(folio)) > + folio_pincount_sub(folio, refs); > else > refs *= GUP_PIN_COUNTING_BIAS; > } > > - put_page_refs(page, refs); > + folio_put_refs(folio, refs); > +} > + > +static void put_compound_head(struct page *page, int refs, unsigned int flags) > +{ > + VM_BUG_ON_PAGE(PageTail(page), page); > + gup_put_folio((struct folio *)page, refs, flags); > } > > /** > @@ -228,7 +214,7 @@ bool __must_check try_grab_page(struct page *page, unsigned int flags) > */ > void unpin_user_page(struct page *page) > { > - put_compound_head(compound_head(page), 1, FOLL_PIN); > + gup_put_folio(page_folio(page), 1, FOLL_PIN); > } > EXPORT_SYMBOL(unpin_user_page); > > -- > 2.33.0 > >
diff --git a/mm/gup.c b/mm/gup.c index 58e5cfaaa676..6d827f7d66d8 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -36,29 +36,11 @@ static void folio_pincount_add(struct folio *folio, int refs) atomic_add(refs, folio_pincount_ptr(folio)); } -static void hpage_pincount_sub(struct page *page, int refs) +static void folio_pincount_sub(struct folio *folio, int refs) { - VM_BUG_ON_PAGE(!hpage_pincount_available(page), page); - VM_BUG_ON_PAGE(page != compound_head(page), page); - - atomic_sub(refs, compound_pincount_ptr(page)); -} - -/* Equivalent to calling put_page() @refs times. */ -static void put_page_refs(struct page *page, int refs) -{ -#ifdef CONFIG_DEBUG_VM - if (VM_WARN_ON_ONCE_PAGE(page_ref_count(page) < refs, page)) - return; -#endif + VM_BUG_ON_FOLIO(!folio_pincount_available(folio), folio); - /* - * Calling put_page() for each ref is unnecessarily slow. Only the last - * ref needs a put_page(). - */ - if (refs > 1) - page_ref_sub(page, refs - 1); - put_page(page); + atomic_sub(refs, folio_pincount_ptr(folio)); } /* @@ -175,19 +157,23 @@ struct page *try_grab_compound_head(struct page *page, return NULL; } -static void put_compound_head(struct page *page, int refs, unsigned int flags) +static void gup_put_folio(struct folio *folio, int refs, unsigned int flags) { if (flags & FOLL_PIN) { - mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_RELEASED, - refs); - - if (hpage_pincount_available(page)) - hpage_pincount_sub(page, refs); + node_stat_mod_folio(folio, NR_FOLL_PIN_RELEASED, refs); + if (folio_pincount_available(folio)) + folio_pincount_sub(folio, refs); else refs *= GUP_PIN_COUNTING_BIAS; } - put_page_refs(page, refs); + folio_put_refs(folio, refs); +} + +static void put_compound_head(struct page *page, int refs, unsigned int flags) +{ + VM_BUG_ON_PAGE(PageTail(page), page); + gup_put_folio((struct folio *)page, refs, flags); } /** @@ -228,7 +214,7 @@ bool __must_check try_grab_page(struct page *page, unsigned int flags) */ void unpin_user_page(struct page *page) { - put_compound_head(compound_head(page), 1, FOLL_PIN); + gup_put_folio(page_folio(page), 1, FOLL_PIN); } EXPORT_SYMBOL(unpin_user_page);
put_compound_head() is turned into a call to gup_put_folio(). This removes the last call to put_page_refs(), so delete it. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- mm/gup.c | 44 +++++++++++++++----------------------------- 1 file changed, 15 insertions(+), 29 deletions(-)