On Mon, May 27, 2024 at 10:01:23PM +0100, Matthew Wilcox (Oracle) wrote:
> We need filesystems to be able to communicate acceptable folio sizes
> to the pagecache for a variety of uses (e.g. large block sizes).
> Support a range of folio sizes between order-0 and order-31.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Co-developed-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
> Signed-off-by: Pankaj Raghav <p.raghav@xxxxxxxxxxx>
> Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
> ---
> For this version, I fixed the TODO that the maximum folio size was not
> being honoured. I made some other changes too like adding const, moving
> the location of the constants, checking CONFIG_TRANSPARENT_HUGEPAGE, and
> dropping some of the functions which aren't needed until later patches.
> (They can be added in the commits that need them). Also rebased against
> current Linus tree, so MAX_PAGECACHE_ORDER no longer needs to be moved).
Thanks for this! So I am currently running my xfstests on the new series
I am planning to send in a day or two based on next-20240523.
I assume this patch is intended to be folded in to the next LBS series?
>
> diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
> index 1ed9274a0deb..c6aaceed0de6 100644
> --- a/include/linux/pagemap.h
> +++ b/include/linux/pagemap.h
> @@ -204,13 +204,18 @@ enum mapping_flags {
> AS_EXITING = 4, /* final truncate in progress */
> /* writeback related tags are not used */
> AS_NO_WRITEBACK_TAGS = 5,
> - AS_LARGE_FOLIO_SUPPORT = 6,
> - AS_RELEASE_ALWAYS, /* Call ->release_folio(), even if no private data */
> - AS_STABLE_WRITES, /* must wait for writeback before modifying
> + AS_RELEASE_ALWAYS = 6, /* Call ->release_folio(), even if no private data */
> + AS_STABLE_WRITES = 7, /* must wait for writeback before modifying
> folio contents */
> - AS_UNMOVABLE, /* The mapping cannot be moved, ever */
> + AS_UNMOVABLE = 8, /* The mapping cannot be moved, ever */
> + AS_FOLIO_ORDER_MIN = 16,
> + AS_FOLIO_ORDER_MAX = 21, /* Bits 16-25 are used for FOLIO_ORDER */
> };
>
> +#define AS_FOLIO_ORDER_MIN_MASK 0x001f0000
> +#define AS_FOLIO_ORDER_MAX_MASK 0x03e00000
As you changed the mapping flag offset, these masks also needs to be
changed accordingly.
I moved(pun intended) the AS_UNMOVABLE and kept the
AS_FOLIO_ORDER_(MIN|MAX) value the same.
AS_FOLIO_ORDER_MIN = 8,
AS_FOLIO_ORDER_MAX = 13, /* Bit 8-17 are used for FOLIO_ORDER */
AS_UNMOVABLE = 18, /* The mapping cannot be moved, ever */
AS_INACCESSIBLE, /* Do not attempt direct R/W access to the mapping */
> +#define AS_FOLIO_ORDER_MASK (AS_FOLIO_ORDER_MIN_MASK | AS_FOLIO_ORDER_MAX_MASK)
> +
>
--
Pankaj
