On Fri, Jan 25, 2013 at 04:45:10PM +1030, Rusty Russell wrote: > Tejun Heo <tj@xxxxxxxxxx> writes: > >> It also implements two stage shutdown, as we need it to tear down the > >> percpu counts. Before dropping the initial refcount, you must call > >> percpu_ref_kill(); this puts the refcount in "shutting down mode" and > >> switches back to a single atomic refcount with the appropriate barriers > >> (synchronize_rcu()). > > > > Maybe if we have tryget() which only succeeds if the counter is alive, > > we can replace moulde refcnt with this? Rusty? > > Yes, it's similar (hence my previous interest), though module count is a > bit weird. I'll try and take a stab at converting it, if I can find time. > Like Tejun, I'd prefer to see it always alloc up-front, because it > avoids the _noalloc variant (which is backwards: please hand gfp_t, so > you don't hide the alloc) and heuristics. Problem with gfp_t is alloc_percpu() doesn't take it. I don't know why, but this all goes away with Tejun's idea for allocating from a pool refilled by workqueue. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
