Re: [PATCH RFC 2/2] mm: Use pte markers for swap errors

[Miaohe Lin]

On 2022/10/25 4:48, Peter Xu wrote:
> PTE markers are ideal mechanism for things like SWP_SWAPIN_ERROR.  Using a
> whole swap entry type for this purpose can be an overkill, especially if we
> already have PTE markers.  Define a new bit for swapin error and replace it
> with pte markers.  Then we can safely drop SWP_SWAPIN_ERROR and give one
> device slot back to swap.
> 
> We used to have SWP_SWAPIN_ERROR taking the page pfn as part of the swap
> entry, but it's never used.  Neither do I see how it can be useful because
> normally the swapin failure should not be caused by a bad page but bad swap
> device.  Drop it alongside.
> 
> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>

Thanks for doing this. I have been waiting this for a "long" time. ;)
With changing the name of PTE_MARKER_SWAP_ERROR proposed by David, this
patch looks good to me.

Reviewed-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>

Thanks,
Miaohe Lin