On Monday, October 17, 2016 1:28:01 PM CEST Bart Van Assche wrote: > On 10/17/2016 01:06 PM, Arnd Bergmann wrote: > > Using an open-coded semaphore as a replacement is probably just > > the last resort that we can consider once we are down to the > > last handful of users. I haven't looked at drivers/infiniband/ > > yet for this, but I believe that drivers/acpi/ is a case for > > which I see no better alternative (the AML bytecode requires > > counting semaphore semantics). > > Hello Arnd, > > Thanks for the detailed reply. However, I doubt that removing and > open-coding counting semaphores is the best alternative. Counting > semaphores are a useful abstraction. I think open-coding counting > semaphores everywhere counting semaphores are used would be a step back > instead of a step forward. Absolutely agreed, that's why I said 'last resort' above. I don't think that we need to go there for infiniband. See my reply for patch 6 for one idea on how to handle hns and mthca. There might be better ways. These fall into the general category of using the counting semaphore to count something that we already know in the code that uses the semaphore, so we can remove the count and just need some other waiting primitive. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html