[PATCH v2 0/2] vmevent: Greater-than attribute + one-shot mode + abugfix

From: Anton Vorontsov
Date: Wed Apr 18 2012 - 04:33:23 EST

Hi all,

That's a respin of the previous patchset that tried to add a new
'cross' event type, which would trigger whenever value crosses a
user-specified threshold both ways, i.e. from a lesser values side
to a greater values side, and vice versa.

We use the event type 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

There's also a fix for a bug that makes kernel upset about sleeping
in the atomic context.

Per Pekka's comments here comes v2. Changes:

- Added a one-shot mode plus a greater-than attribute, the two
additions makes the equivalent of the cross-event type.
- In the bugfix patch I added some comments about implementation
details of the lock-free logic. Also, in the previous version of
the fix I forgot to remove 'struct mutex' form the
'struct vmevent_watch', this is now cleaned up.

As usual, the patches are against

git://github.com/penberg/linux.git vmevent/core


Anton Vorontsov
Email: cbouatmailru@xxxxxxxxx
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