Re: [PATCH 04/12] bdi: initialize ->ra_pages and ->io_pages in bdi_init

From: Jan Kara
Date: Thu Sep 17 2020 - 06:05:26 EST


On Thu 10-09-20 16:48:24, Christoph Hellwig wrote:
> Set up a readahead size by default, as very few users have a good
> reason to change it.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Acked-by: David Sterba <dsterba@xxxxxxxx> [btrfs]
> Acked-by: Richard Weinberger <richard@xxxxxx> [ubifs, mtd]

Looks good but what about coda, ecryptfs, and orangefs? Currenly they have
readahead disabled and this patch would seem to enable it?

> diff --git a/mm/backing-dev.c b/mm/backing-dev.c
> index 8e8b00627bb2d8..2dac3be6127127 100644
> --- a/mm/backing-dev.c
> +++ b/mm/backing-dev.c
> @@ -746,6 +746,8 @@ struct backing_dev_info *bdi_alloc(int node_id)
> kfree(bdi);
> return NULL;
> }
> + bdi->ra_pages = VM_READAHEAD_PAGES;
> + bdi->io_pages = VM_READAHEAD_PAGES;

Won't this be more logical in bdi_init() than in bdi_alloc()?

Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR