Re: [RFC 2/3] mm: Add a new page flag PageLayzyFree() for MADV_FREE

Wei Yang
2020-03-15T08:19:07Z

On Fri, Feb 28, 2020 at 11:38:18AM +0800, Huang, Ying wrote:
>From: Huang Ying <ying.huang@intel.com>
>
>Now !PageSwapBacked() is used as the flag for the pages freed lazily
>via MADV_FREE. This isn't obvious enough. So Dave suggested to add a
>new page flag for that to improve the code readability.

I am confused with the usage of PageSwapBacked().

Previously I thought this flag means the page is swapin, set in
swapin_readahead(). While I found page_add_new_anon_rmap() would set it too.
This means every anon page would carry this flag. Then what is this flag
means?

--
Wei Yang
Help you, Help me