On Tue, 2007-07-31 at 11:33 -0400, Gregory Haskins wrote: > >>> On Tue, Jul 31, 2007 at 10:25 AM, in message <1185891957.12034.12.camel@twins>, > Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote: > >(with mistakes). > > If there was anything more than what you already mention here, please > point them out so I don't "port" them over to the workqueues > implemenation ;) The two that jumped out at me while skimming over the code were: - use of raw_spinlock_t (while not always a bug, it does need _very_ good justification) - not cpu hotplug safe > > Your idea that GFP_ATOMIC is broken in -rt is unfortunate, it isn't. The > > whole allocator is preemptable - that is a feature! > > Heh...that may be, and I can see how it is useful to have the > allocatorr be generally preemptible. However, I would have thought > that "GFP_ATOMIC" means I can call it from atomic code, which is not > the case apparently. It's probably just my own ignorance again of > what that flag should really mean ;) > > In any case I abstracted the heap_allocator away so that I could make > an in_atomic friendly allocation. If the GFP_ATOMIC allocator ever > supports in_atomic in the future, all we have to do is change > vfcipi/heap.h. I am open to other suggestions to this problem, of > course. The thing is, we should never need to allocate from a real atomic context, every time you end up in that situation, ask yourself if the problem can be solved differently. That is, it often points at a design flaw. Peter - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
