On Thu, Jul 14, 2016 at 04:58:44PM +0200, Oleg Nesterov wrote: > > But note that we do not need RCU_NONE. All we need is the trivial change > below.
Hurm, maybe. So having that unbalanced keeps us in GP_PASSED state and since we'll never drop gp_count back to 0 nothing will ever happen. Cute, yes. > Damn, I am trying to find my old rcu-sync patches which I didn't > send, but can't... OK, this almost off-topic right now, just this "enter" > is ugly and we can't switch the slow/fast modes dynamically. > > The rest of you patch is "optimize the slow path" and we already discussed > it before, I personally like it. Perhaps you can redo it without RCU_NONE > part? Indeed, I rebased that patch on top of the current tree and had to add support for down_trylock() but otherwise much the same thing. I can send it out again.
