Hello, Andrew. On Thu, Jul 31, 2014 at 6:03 PM, Andrew Morton <a...@linux-foundation.org> wrote: > I don't think we should add facilities such as this. Because if we do, > people will use them and thereby make the kernel less reliable, for > obvious reasons. > > It would be better to leave the nasty hack localized within > blk-throttle.c and hope that someone finds a way of fixing it.
The thing is we need similar facilities in the IO path in other places too. They share exactly the same characteristics - opportunistic percpu allocations during IO which are expected to fail from time to time and they will all implement fallback behavior on allocation failures. I'm not sure how this makes the kernel less reliable. This conceptually isn't different from atomic allocations which we also use in a similar way. If you're worried that people might use this assuming that it won't fail, an obvious solution is adding a failure injection for debugging, but really except for being a bit ghetto, this is just the atomic allocation for percpu areas. Thanks. -- tejun -- 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/