Re: [PATCH 0/2] mm: Use pte marker for swapin errors

[Huang, Ying]

Peter Xu <peterx@xxxxxxxxxx> writes:

> On Mon, Oct 31, 2022 at 09:40:15AM +0800, Huang, Ying wrote:
>> Peter Xu <peterx@xxxxxxxxxx> writes:
>> 
>> > rfc->v1:
>> > - Rename SWAP_ERROR -> SWAPIN_ERROR [David, Miaohe]
>> > - Added r-bs for Ying and Miaohe
>> >
>> > Hi,
>> >
>> > This series uses the pte marker to replace the swapin error swap entry,
>> > then we save one more swap entry slot for swap devices.  A new pte marker
>> > bit is defined.
>> 
>> Per my understanding, "swap entry" describes one swap page (4KB on x86)
>> in one swap device.  So, the original swapin error implementation uses
>> one swap file (or swap device) instead of one swap entry.  So your patch
>> saves one swap file (or swap device).
>
> Yeah I was definitely not accurate enough, I wanted to use "slot" to mean
> "type" here but obviously I didn't make it, sorry.  Hopefully the whole
> patchset is still clear enough anyway so no reader will get confused by it.

The terminology used in swap code is a little complex.  The swap slot is
used to describe swap entry (swap page) too in swap slots cache
(swap_slots.c/h).

Best Regards,
Huang, Ying