Re: [PATCHv6 03/37] page-flags: relax page flag policy for few flags

From: Matthew Wilcox
Date: Wed Feb 08 2017 - 23:02:41 EST


On Thu, Jan 26, 2017 at 02:57:45PM +0300, Kirill A. Shutemov wrote:
> These flags are in use for filesystems with backing storage: PG_error,
> PG_writeback and PG_readahead.

Oh ;-) Then I amend my comment on patch 1 to be "patch 3 needs to go
ahead of patch 1" ;-)

> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> ---
> include/linux/page-flags.h | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
> index 6b5818d6de32..b85b73cfb1b3 100644
> --- a/include/linux/page-flags.h
> +++ b/include/linux/page-flags.h
> @@ -263,7 +263,7 @@ static inline int TestClearPage##uname(struct page *page) { return 0; }
>
> __PAGEFLAG(Locked, locked, PF_NO_TAIL)
> PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD)
> -PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND)
> +PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL)
> PAGEFLAG(Referenced, referenced, PF_HEAD)
> TESTCLEARFLAG(Referenced, referenced, PF_HEAD)
> __SETPAGEFLAG(Referenced, referenced, PF_HEAD)
> @@ -303,15 +303,15 @@ PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY)
> * Only test-and-set exist for PG_writeback. The unconditional operators are
> * risky: they bypass page accounting.
> */
> -TESTPAGEFLAG(Writeback, writeback, PF_NO_COMPOUND)
> - TESTSCFLAG(Writeback, writeback, PF_NO_COMPOUND)
> +TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL)
> + TESTSCFLAG(Writeback, writeback, PF_NO_TAIL)
> PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL)
>
> /* PG_readahead is only used for reads; PG_reclaim is only for writes */
> PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL)
> TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL)
> -PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND)
> - TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND)
> +PAGEFLAG(Readahead, reclaim, PF_NO_TAIL)
> + TESTCLEARFLAG(Readahead, reclaim, PF_NO_TAIL)
>
> #ifdef CONFIG_HIGHMEM
> /*
> --
> 2.11.0
>
> --
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