Re: [RFC][PATCH 0/1] MAZE: Mazed processes monitor

Andi Kleen
2008-05-13T21:08:40Z

Hirofumi Nakagawa <hnakagawa@miraclelinux.com> writes:

> This patch provides the mazed process monitor,named MAZE.
> MAZE's purpose is to notify or terminate registered processes when they are mazed.
> The definition of mazed process is a process using excessive CPU cycles,
> that is long time keeping TASK_RUNNING state.

Isn't that very similar to RLIMIT_CPU? The main difference seems to be
that they're regularly reset and that they can be more fine grained
than seconds.

How about you implement a way to change the RLIMIT_CPU limit
of a running task (and possibly fix it to use a finer grained unit
if you need <1s resolution).

Then you could run a user space daemon running with lower priority that
just regularly resets the RLIMIT_CPUs of all running processes.

If some RT process uses so much time that the user daemon cannot
keep up its cpu time limit will be eventually exceeded and it will
be killed.

I think that would be a far cleaner and generic way to implement
this.

-Andi