Using SSDs as swap

[Willem Jan Withagen]

On 8-8-2015 12:29, Konstantin Belousov wrote:
> On Sat, Aug 08, 2015 at 12:06:06PM +0200, Willem Jan Withagen wrote:

>> 2) Does the SSD "suffer" unneeded from swapping on it?
> Depends on your swapping activity, but yes, I believe that intense swapping
> would wear SSD in the short time.

Would it be more intense than being beaten to death as a ARC cache??

If I look at most of my systems I try to prevent them even using really
swap since that usually kills performance big time...
So things get swapped out under pressure, but rarely get swapped back
in, because the LRU properties of that part of the application minimise
that chance of things getting paged back in.

So the number of times that swap actually gets used is rather seldom.

In writting swap, how are the allocations made where things are swapped.
Do things always end up in a lineair order on swap writting things as
close to the start as slots in swap allow it. SSD would profit from it
being sort of a circular buffer...
(Guess I have to try and understand the swap code.... )

--WjW