Re: [PATCH] mm : update ra->ra_pages if it's NOT equal to bdi->ra_pages

[Matthew Wilcox]

On Fri, Aug 14, 2020 at 09:30:11AM +0800, Zhaoyang Huang wrote:
> file->f_ra->ra_pages will remain the initialized value since it opend, which may
> be NOT equal to bdi->ra_pages as the latter one is updated somehow(etc,
> echo xxx > /sys/block/dm/queue/read_ahead_kb).So sync ra->ra_pages to the
> updated value when sync read.

It still ignores the work done by shrink_readahead_size_eio()
and fadvise(POSIX_FADV_SEQUENTIAL).