Re: A Plumberâs Wish List for Linux

From: Lennart Poettering
Date: Sun Oct 30 2011 - 13:18:50 EST

On Tue, 25.10.11 13:40, Li Zefan (lizf@xxxxxxxxxxxxxx) wrote:

> > cgroups provides us with all of that, though the last two items only in
> > a suboptimal way: notification of cgroups running empty is ugly, since
> > it is done by spawning a usermode helper (we'd prefer a netlink msg or
> > so), and the process killing is a bit racy.
> How about using eventfd? You can create an eventfd for the specific "tasks"
> file, and when the cgroup gets empty (no task in it), you'll get a notification.
> It should be easy to implement, since cgroup already supports eventfd-based
> API.

I am quite convinced that using eventfd() like this is quite ugly. The
current evetnfd() logic is not recursive anyway, hence wouldn't help us


Lennart Poettering - Red Hat, Inc.
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