Re: [PATCH v2 3/4] mm/truncate: bail out early from invalidate_inode_pages2_range() if mapping is empty
From: Jan Kara
Date: Tue Apr 25 2017 - 04:39:26 EST
On Mon 24-04-17 19:41:34, Andrey Ryabinin wrote:
> If mapping is empty (both ->nrpages and ->nrexceptional is zero) we can
> avoid pointless lookups in empty radix tree and bail out immediately after
> cleancache invalidation.
>
> Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Looks good. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> mm/truncate.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/mm/truncate.c b/mm/truncate.c
> index 6263aff..8f12b0e 100644
> --- a/mm/truncate.c
> +++ b/mm/truncate.c
> @@ -624,6 +624,9 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
> int did_range_unmap = 0;
>
> cleancache_invalidate_inode(mapping);
> + if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
> + return 0;
> +
> pagevec_init(&pvec, 0);
> index = start;
> while (index <= end && pagevec_lookup_entries(&pvec, mapping, index,
> --
> 2.10.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR