RE: [PATCH v4] vmevent: Implement greater-than attribute state andone-shot mode

[leonid.moiseichuk]

> -----Original Message-----
> From: ext Minchan Kim [mailto:minchan@xxxxxxxxxx]
> Sent: 02 May, 2012 08:04
> To: Anton Vorontsov
> Cc: KOSAKI Motohiro; Rik van Riel; Pekka Enberg; Moiseichuk Leonid (Nokia-
...
> I think hardest problem in low mem notification is how to define _lowmem
> situation_.
> We all guys (server, desktop and embedded) should reach a conclusion on
> define lowmem situation before progressing further implementation
> because each part can require different limits.
> Hopefully, I want it.
> 
> What is the best situation we can call it as "low memory"?

That depends on what user-space can do. In n9 case [1] we can handle some OOM/slowness-prevention and actions e.g. close background applications, stop prestarted apps, 
flush browser/graphics caches in applications and do all the things kernel even don't know about. This set of activities usually comes as memory management design.

From another side, polling by re-scan vmstat data using procfs might be performance heavy and for sure - use-time disaster.

Leonid
[1] http://maemo.gitorious.org/maemo-tools/libmemnotify - yes, not ideal but it works and quite well isolated code.
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