Messages in this thread | | | Date | Thu, 03 Mar 2005 19:41:06 -0500 | From | Jeff Garzik <> | Subject | Re: [PATCH][16/26] IB/mthca: mem-free doorbell record writing |
| |
Roland Dreier wrote: > Jeff> Are you concerned about ordering, or write-combining? > > ordering... write combining would be fine. > > Jeff> I am unaware of a situation where writes are re-ordered into > Jeff> a reversed, descending order for no apparent reason. > > Hmm... I've seen ppc64 do some pretty freaky reordering but on the > other hand that's a 64-bit arch so we don't care in this case. I > guess I'd rather keep the barrier there so we don't have the > possibility of a rare hardware crash when the HCA just happens to read > the doorbell record in a corrupt state.
Well, we don't just add code to "hope and pray" for an event that nobody is sure can even occur...
Does someone have a concrete case where this could happen? ever?
Jeff
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |