Re: [RFC] sched: implement the exclusive wait queue as a LIFO queue
From: David Howells
Date: Wed Apr 28 2010 - 05:31:48 EST
Changli Gao <xiaosuo@xxxxxxxxx> wrote:
> If there isn't enough work to be done, we'd better not disrupt them
> and leave them sleeping forever to keep the scheduler happier. Do we
> have reason to keep fair to all the workers? Does it have benefit?
You've made one important assumption: the processes on the wait queue are
sleeping waiting to service things... but what if the wait queue governs
access to a resource, and all the processes on that wait queue need access to
that resource to do things? Some of the processes waiting for it may never
get a go, and so necessary work may be left undone.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/