On 5/11/21 11:47 PM, Matthew Wilcox (Oracle) wrote:
> These new functions are the folio analogues of the various PageFlags
> functions. If CONFIG_DEBUG_VM_PGFLAGS is enabled, we check the folio
> is not a tail page at every invocation. This will also catch the
> PagePoisoned case as a poisoned page has every bit set, which would
> include PageTail.
>
> This saves 1727 bytes of text with the distro-derived config that
> I'm testing due to removing a double call to compound_head() in
> PageSwapCache().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Acked-by: Jeff Layton <jlayton@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Some nits:
...
> * Macros to create function definitions for page flags
> */
> #define TESTPAGEFLAG(uname, lname, policy) \
> +static __always_inline bool folio_##lname(struct folio *folio) \
> +{ return test_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
> static __always_inline int Page##uname(struct page *page) \
> { return test_bit(PG_##lname, &policy(page, 0)->flags); }
Maybe unify these idents while at it?
>
> #define SETPAGEFLAG(uname, lname, policy) \
> +static __always_inline \
> +void folio_set_##lname##_flag(struct folio *folio) \
> +{ set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
> static __always_inline void SetPage##uname(struct page *page) \
> { set_bit(PG_##lname, &policy(page, 1)->flags); }
>
> #define CLEARPAGEFLAG(uname, lname, policy) \
> +static __always_inline \
> +void folio_clear_##lname##_flag(struct folio *folio) \
> +{ clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
> static __always_inline void ClearPage##uname(struct page *page) \
> { clear_bit(PG_##lname, &policy(page, 1)->flags); }
>
> #define __SETPAGEFLAG(uname, lname, policy) \
> +static __always_inline \
> +void __folio_set_##lname##_flag(struct folio *folio) \
> +{ __set_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
> static __always_inline void __SetPage##uname(struct page *page) \
> { __set_bit(PG_##lname, &policy(page, 1)->flags); }
>
> #define __CLEARPAGEFLAG(uname, lname, policy) \
> +static __always_inline \
> +void __folio_clear_##lname##_flag(struct folio *folio) \
> +{ __clear_bit(PG_##lname, folio_flags(folio, FOLIO_##policy)); } \
> static __always_inline void __ClearPage##uname(struct page *page) \
> { __clear_bit(PG_##lname, &policy(page, 1)->flags); }
>
> #define TESTSETFLAG(uname, lname, policy) \
> +static __always_inline \
> +bool folio_test_set_##lname##_flag(struct folio *folio) \
The line above seems to need extra tab before '\'
(used vimdiff on your git tree)
