| Message ID | 20210622121551.3398730-3-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Folio-enabling the page cache | expand |
> +static inline void *folio_rmapping(struct folio *folio) This name, just like the old one is not exaclty descriptive. I guess the r stands for raw somehow? As a casual contributor to the fringes of the MM I would have no idea when to use it. All this of course also applies to the existing (__)page_rmapping, but maybe this is a good time to sort it out. > > struct anon_vma *page_anon_vma(struct page *page) > { > + struct folio *folio = page_folio(page); > + unsigned long mapping = (unsigned long)folio->mapping; > > if ((mapping & PAGE_MAPPING_FLAGS) != PAGE_MAPPING_ANON) > return NULL; > + return folio_rmapping(folio); It feelds kinda silly to not just open code folio_rmapping here given that we alredy went half the way.
On Wed, Jun 23, 2021 at 09:56:58AM +0200, Christoph Hellwig wrote: > > +static inline void *folio_rmapping(struct folio *folio) > > This name, just like the old one is not exaclty descriptive. I guess the > r stands for raw somehow? As a casual contributor to the fringes of the > MM I would have no idea when to use it. > > All this of course also applies to the existing (__)page_rmapping, but > maybe this is a good time to sort it out. Yes, good point. I don't like the name rmapping either, since we already have rmap which has nothing to do with this. I'll leave page_rmapping() alone for now; no need to add that churn. I think they all become calls to folio_raw_mapping() later. > > > > struct anon_vma *page_anon_vma(struct page *page) > > { > > + struct folio *folio = page_folio(page); > > + unsigned long mapping = (unsigned long)folio->mapping; > > > > if ((mapping & PAGE_MAPPING_FLAGS) != PAGE_MAPPING_ANON) > > return NULL; > > + return folio_rmapping(folio); > > It feelds kinda silly to not just open code folio_rmapping here > given that we alredy went half the way. Yeah, I thought about that too. Done: - return folio_rmapping(folio); + return (void *)(mapping - PAGE_MAPPING_ANON);
diff --git a/mm/internal.h b/mm/internal.h index 76ddcf55012c..3e70121c71c7 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -34,6 +34,13 @@ void page_writeback_init(void); +static inline void *folio_rmapping(struct folio *folio) +{ + unsigned long mapping = (unsigned long)folio->mapping; + + return (void *)(mapping & ~PAGE_MAPPING_FLAGS); +} + vm_fault_t do_swap_page(struct vm_fault *vmf); void folio_rotate_reclaimable(struct folio *folio); diff --git a/mm/util.c b/mm/util.c index a8766e7f1b7f..0ba3a56c2c90 100644 --- a/mm/util.c +++ b/mm/util.c @@ -635,21 +635,10 @@ void kvfree_sensitive(const void *addr, size_t len) } EXPORT_SYMBOL(kvfree_sensitive); -static inline void *__page_rmapping(struct page *page) -{ - unsigned long mapping; - - mapping = (unsigned long)page->mapping; - mapping &= ~PAGE_MAPPING_FLAGS; - - return (void *)mapping; -} - /* Neutral page->mapping pointer to address_space or anon_vma or other */ void *page_rmapping(struct page *page) { - page = compound_head(page); - return __page_rmapping(page); + return folio_rmapping(page_folio(page)); } /** @@ -680,13 +669,12 @@ EXPORT_SYMBOL(folio_mapped); struct anon_vma *page_anon_vma(struct page *page) { - unsigned long mapping; + struct folio *folio = page_folio(page); + unsigned long mapping = (unsigned long)folio->mapping; - page = compound_head(page); - mapping = (unsigned long)page->mapping; if ((mapping & PAGE_MAPPING_FLAGS) != PAGE_MAPPING_ANON) return NULL; - return __page_rmapping(page); + return folio_rmapping(folio); } /**
Convert __page_rmapping to folio_rmapping and move it to mm/internal.h. It's only a couple of instructions (load and mask), so it's definitely going to be cheaper to inline it than call it. Leave page_rmapping out of line. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- mm/internal.h | 7 +++++++ mm/util.c | 20 ++++---------------- 2 files changed, 11 insertions(+), 16 deletions(-)