| Message ID | 20210715033704.692967-53-willy@infradead.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Memory folios | expand |
Matthew Wilcox (Oracle) <willy@infradead.org> wrote: > Convert __page_rmapping to folio_raw_mapping 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> I assume you're going to call it from another source file at some point, otherwise this is unnecessary. Apart from that, Reviewed-by: David Howells <dhowells@redhat.com>
On 7/15/21 5:35 AM, Matthew Wilcox (Oracle) wrote: > Convert __page_rmapping to folio_raw_mapping 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. Maybe mention the page_anon_vma() in changelog too? > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Vlastimil Babka <vbabka@suse.cz>
On Tue, Aug 10, 2021 at 09:42:13PM +0100, David Howells wrote: > Matthew Wilcox (Oracle) <willy@infradead.org> wrote: > > > Convert __page_rmapping to folio_raw_mapping 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> > > I assume you're going to call it from another source file at some point, > otherwise this is unnecessary. Yes, it gets called from mm/ksm.c in a later patch in this series. __page_rmapping() assumes it's being passed a head page and folio_raw_mapping() asserts that. Eventually, page_rmapping() can go away (and maybe it should have been moved to folio-compat.c), but I'm not inclined to do that now. > Apart from that, > > Reviewed-by: David Howells <dhowells@redhat.com> >
On Wed, Aug 11, 2021 at 03:59:06PM +0200, Vlastimil Babka wrote: > On 7/15/21 5:35 AM, Matthew Wilcox (Oracle) wrote: > > Convert __page_rmapping to folio_raw_mapping 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. > > Maybe mention the page_anon_vma() in changelog too? Convert __page_rmapping to folio_raw_mapping 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. Change page_anon_vma() to not call folio_raw_mapping() -- it's more efficient to do the subtraction than the mask.
diff --git a/mm/internal.h b/mm/internal.h index 1a8851b73031..fa31a7f0ed79 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -34,6 +34,13 @@ void page_writeback_init(void); +static inline void *folio_raw_mapping(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 e8c12350b3eb..d0aa1d9c811e 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_raw_mapping(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 (void *)(mapping - PAGE_MAPPING_ANON); } /**
Convert __page_rmapping to folio_raw_mapping 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(-)