On Mon, Nov 19, 2007 at 02:08:03PM +0100, Ingo Molnar wrote: > > #define for_each_leaf_cfs_rq(rq, cfs_rq) \ > > - list_for_each_entry(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list) > > + list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list) > > > > /* Do the two (enqueued) entities belong to the same group ? */ > > static inline int > > @@ -1126,7 +1126,10 @@ static void print_cfs_stats(struct seq_f > > #ifdef CONFIG_FAIR_GROUP_SCHED > > print_cfs_rq(m, cpu, &cpu_rq(cpu)->cfs); > > #endif > > + > > + rcu_read_lock(); > > for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq) > > print_cfs_rq(m, cpu, cfs_rq); > > + rcu_read_unlock(); > > hm, why is this a cleanup?
Sorry for the wrong subject. It was supposed to include the above bug fix, related to how we walk the task group list. Thinking abt it now, I realize that print_cfs_rq() can potentially sleep and hence it cannot be surrounded by rcu_read_lock()/unlock(). And as Dipankar just pointed me, sched_create/destroy_group aren't serialized at all currently, so we need a mutex to protect them. The same mutex can be then used when walking the list in print_cfs_stats() .. Will send update patches soon .. -- Regards, vatsa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
