Re: [PATCH 2/4] send callback when swap slot is freed

Nitin Gupta
2009-09-20T15:03:53Z

Hi Pekka,

On 09/19/2009 12:57 PM, Pekka Enberg wrote:
>
> Nitin Gupta wrote:
>> It is understood that this swap notify callback is bit of a hack. I think
>> we will not gain much trying to beautify this hack. However, I agree with
>> Hugh's suggestion to rename this notify callback related
>> function/variables
>> to make it explicit that its completely ramzswap related. I will send
>> a path that affects these renames as reply to patch 0/4.
>
> I don't quite agree and do think that my approach is a better long-term
> solution. That said, it's Hugh's call, not mine. Hugh?
>

Ok, lets discard all this. I will soon start working on a generic notifier based
interface for various swap events: swapon, swapoff, swap slot free that I hope would
be more acceptable. I will now surely miss this merge window but I hope the end result
would be better.

The issue of swap_lock is still bugging me but I think atomic notifier list should
be acceptable for swap slot free event, at least for the initial revision. If this
particular event finds more users then we will have to work on reducing contention
on swap_lock (per-swap file lock?).

Thanks,
Nitin