On Tue, Jul 23, 2013 at 11:48 AM, Peter Zijlstra <pet...@infradead.org> wrote: > > On Tue, Jul 23, 2013 at 10:13:33AM +0200, Stephane Eranian wrote: > > Hi, > > > > I am looking at ctx_pinned_sched_in() and > > ctx_flexible_sched_in() and I am trying to > > understand the difference of treatment in > > case of errors for the two classes of events > > (pinned vs. flexible). > > > > For pinned events, when a group fails to > > schedule in, the code goes on to the next > > group and therefore walks the entire list > > for each scheduler invocation. > > > > For flexible events, when a group fails, > > the loop aborts and no subsequent group > > is tried. > > > > I am trying to understand the motivation for > > this difference here. > > > > If I recall, the abort is here to limit malicious > > DoS where a malicious user would provide > > an arbitrary long list of events, hogging the kernel. > > But in the case of pinned events, this is ignored > > because to create such events one needs to be > > root in the first place. > > > > Am I getting this right? > > Whee, long time ago. I think the biggest reason is that pinned events > should always be scheduled. Not being able to schedule a pinned event is > an error. But yes, that and the fact that they're root only. > > Ok, that's what I thought then. Thanks, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
