On Thu, 2007-07-12 at 12:46 +0200, Jarek Poplawski wrote: > On Thu, Jul 12, 2007 at 12:18:23PM +0300, Ranko Zivojnovic wrote: > > On Thu, 2007-07-12 at 09:37 +0200, Jarek Poplawski wrote: > > > - setup_timer(&elist[idx].timer, est_timer, est->interval); > > > + setup_timer(&elist[idx].timer, est_timer, idx); > > > > I left this because setup_timer expects unsigned long. > > Are there any warnings? It'll look strange without such comment. > I didn't check this, but maybe idx should be unsigned too? >
I'll make idx unsigned. > > > > > - gen_kill_estimator is called during qdisc_destroy under > > > dev->queue_lock, > > > - est_timer is running and waiting on this lock just on the > > > list entry of the destroyed class, > > > - gen_kill_estimator kills the entry and returns, > > > - in xxx_destroy_class kfree(cl) is done etc., > > > - est_timer gets the lock and does nbytes = e->bstats->bytes or > > > e->rate_est-bps = ... with freed memory. > ... > > I don't mind fixing all the classful qdiscs to call_rcu() to release > > their class structures for consistency purposes ... in fact ... that is > > exactly what I will do in order to avoid any potential future mishaps. > > One may actually decide in the future to add a callback to a user > > defined function to update some qdisc/class specific rates and given > > this inconsistency in handling qdiscs vs classes - it could have a nasty > > backfire. > > I don't know if such broad changes are acceptable, or if it's even > required that these structs have to belong to a class struct. > > IMHO, unless I miss something, they could be included into > gen_estimator struct after some api change. BTW, maybe it would be > resonable to return a pointer to such gen_estimator from > gen_new_estimator, then lookups could be avoided in > gen_kill_estimator. > > Alas, there is probably more (of course very unprobable): there > is no dev_hold for gen_estimator now, so I hope it'll always manage > to unlock in time - before dev is freed. > I agree - it does look like the most sensible thing to do - have gnet_stats_basic and gnet_stats_rate_est allocated within the gen_estimator struct rather than pointers looking here and there - and provide api to maintain those stats - it simplifies the picture. Also - the stats_lock in this case could be local to gen_estimator struct, thus making the implementation completely "dev agnostic" - and will not break on dev removal. All this however will require a rather intrusive "surgical procedure" to fix all the references. I don't mind implementing and testing it - given there's consensus from maintainers on the "correctness". Waiting for feedback. R. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
