Re: Expense of read_iter

[Matthew Wilcox]

On Wed, Jan 20, 2021 at 10:12:01AM -0500, Mikulas Patocka wrote:
> Do you have some idea how to optimize the generic code that calls 
> ->read_iter?

Yes.

> It might be better to maintain an f_iocb_flags in the
> struct file and just copy that unconditionally.  We'd need to remember
> to update it in fcntl(F_SETFL), but I think that's the only place.

Want to give that a try?