Re: [PATCH v4] mm: Enable suspend-only swap spaces

[Karel Zak]

On Mon, Jul 26, 2021 at 05:12:46PM -0700, Evan Green wrote:
> Swap regions with SWAP_FLAG_HIBERNATE_ONLY set will not appear in
> /proc/meminfo under SwapTotal and SwapFree, since they are not usable as
> general swap. These regions do still appear in /proc/swaps.

Off-topic, /proc/swaps is in the same situation like /proc/mounts years ago ...

It does not provide all important information like SWAP_FLAG_DISCARD_PAGES
SWAP_FLAG_DISCARD_ONCE and SWAP_FLAG_HIBERNATE_ONLY flags. 

Users will not able to differentiate between regular and hibernate-only
devices in "swapon" or "cat /proc/swaps" output ;-(

It would be nice to have /proc/swapsinfo with extendible "flags" column.

 Karel


-- 
 Karel Zak  <kzak@xxxxxxxxxx>
 http://karelzak.blogspot.com