Commit 64601000 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

mm: Add folio_raw_mapping() 



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.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
parent bf6bd276

mm/internal.h

+7 −0
Original line number Diff line number Diff line
@@ -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);

mm/util.c

+4 −16
Original line number Diff line number Diff line
@@ -654,21 +654,10 @@ void *kvrealloc(const void *p, size_t oldsize, size_t newsize, gfp_t flags) 
}

EXPORT_SYMBOL(kvrealloc);



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));

}



/**
@@ -699,13 +688,12 @@ 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);

}



/**