Re: [PATCH v3 RESEND] mm: shmem: implement POSIX_FADV_[WILL|DONT]NEED for shmem

[Matthew Wilcox]

On Tue, Jan 18, 2022 at 05:05:40PM +0530, Charan Teja Kalla wrote:
> Hello Matthew,
> 
> > Yes.  This should obviously be an xa_for_each() loop.
> 
> In one of your patch[1], where we used xarray iterator, though most of
> the entries found requires to call xas_pause() but still endup in using
> xas_for_each() rather than xa_for_each(). Then, Should this code be
> changed to use xa_for_each()? The documentation also says that "The
> xas_for_each() iterator will expand into more inline code than
> xa_for_each()."
> 
> [1]https://patchwork.kernel.org/project/linux-mm/patch/20200819184850.24779-4-willy@xxxxxxxxxxxxx/

How do you know the distribution of swap and non-swap entries in that
region of that xarray?