Re: Expense of read_iter

[Mikulas Patocka]

On Thu, 21 Jan 2021, Matthew Wilcox wrote:

> 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?

Yes - send me the patch and I'll benchmark it.

Mikulas