Re: [patch 9/9] Scheduler profiling - Use conditional calls

Mathieu Desnoyers
2007-06-04T22:21:15Z

* William Lee Irwin III (wli@holomorphy.com) wrote:
> On Wed, May 30, 2007 at 10:00:34AM -0400, Mathieu Desnoyers wrote:
> >>> + if (prof_on)
> >>> + BUG_ON(cond_call_arm("profile_on"));
>
> * William Lee Irwin III (wli@holomorphy.com) wrote:
> >> What's the point of this BUG_ON()? The condition is a priori impossible.
>
> On Thu, May 31, 2007 at 05:12:58PM -0400, Mathieu Desnoyers wrote:
> > Not impossible: hash_add_cond_call() can return -ENOMEM if kmalloc lacks
> > memory.
>
> Shouldn't it just propagate the errors like anything else instead of
> going BUG(), then? One can easily live without profiling if the profile
> buffers should fail to be allocated e.g. due to memory fragmentation.
>
> These things all have to handle errors for hotplugging anyway AIUI.
>

Cond call arming will not reserve memory anymore in the next release.
(hash table is gone).