On Mon, May 21, 2018 at 5:33 PM, Paul E. McKenney <paul...@linux.vnet.ibm.com> wrote: > On Mon, May 21, 2018 at 08:16:59AM -0700, Linus Torvalds wrote: >> On Mon, May 21, 2018 at 6:51 AM Roman Penyaev < >> roman.peny...@profitbricks.com> wrote: >> >> > No, I continue from the pointer, which I assigned on the previous IO >> > in order to send IO fairly and keep load balanced. >> >> Right. And that's exactly what has both me and Paul nervous. You're no >> longer in the RCU domain. You're using a pointer where the lifetime has >> nothing to do with RCU any more. >> >> Can it be done? Sure. But you need *other* locking for it (that you haven't >> explained), and it's fragile as hell. > > He looks to actually have it right, but I would want to see a big comment > on the read side noting the leak of the pointer and documenting why it > is OK.
Hi Paul and Linus, Should I resend current patch with more clear comments about how careful caller should be with a leaking pointer? Also I will update read side with a fat comment about "rcu_assign_pointer()" which leaks the pointer out of RCU domain and what is done to prevent nasty consequences. Does that sound acceptable? -- Roman
