Re: [PATCH 2/2] vmevent: Implement greater-than attribute and one-shotmode

From: Pekka Enberg
Date: Wed Apr 18 2012 - 16:01:39 EST


On Wed, 18 Apr 2012, Anton Vorontsov wrote:
> This patch implements a new event type, it will trigger whenever a
> value becomes greater than user-specified threshold, it complements
> the 'less-then' trigger type.
>
> Also, let's implement the one-shot mode for the events, when set,
> userspace will only receive one notification per crossing the
> boundaries.
>
> Now when both LT and GT are set on the same level, the event type
> works as a cross event type: it triggers whenever a value crosses
> the threshold from a lesser values side to a greater values side,
> and vice versa.
>
> We use the event types in an userspace low-memory killer: we get a
> notification when memory becomes low, so we start freeing memory by
> killing unneeded processes, and we get notification when memory hits
> the threshold from another side, so we know that we freed enough of
> memory.
>
> Signed-off-by: Anton Vorontsov <anton.vorontsov@xxxxxxxxxx>

Did you try vmevent-test with this patch? I'm seeing this:

Physical pages: 109858
read failed: Invalid argument

Pekka
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