Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH RFC tip/core/rcu 6/7] rcu: Move early-boot callbacks to no-CBs lists for no-CBs CPUs | Date | Wed, 21 Jan 2015 02:08:19 -0800 |
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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
When a CPU is first determined to be a no-CBs CPUs, this commit causes any early boot callbacks to be moved to the no-CBs callback list, allowing them t obe invoked.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> --- kernel/rcu/tree.c | 1 + kernel/rcu/tree_plugin.h | 24 ++++++++++++------------ 2 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 02fa29a4d104..c5241cdd4daf 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2852,6 +2852,7 @@ __call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu), * and then drop through to queue the callback. */ BUG_ON(cpu != -1); + WARN_ON_ONCE(!rcu_is_watching()); if (!likely(rdp->nxtlist)) init_default_callback_list(rdp); } diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 9b7f8c8ca355..bb947ef1a2a4 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2386,18 +2386,8 @@ void __init rcu_init_nohz(void) pr_info("\tPoll for callbacks from no-CBs CPUs.\n"); for_each_rcu_flavor(rsp) { - for_each_cpu(cpu, rcu_nocb_mask) { - struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu); - - /* - * If there are early callbacks, they will need - * to be moved to the nocb lists. - */ - WARN_ON_ONCE(rdp->nxttail[RCU_NEXT_TAIL] != - &rdp->nxtlist && - rdp->nxttail[RCU_NEXT_TAIL] != NULL); - init_nocb_callback_list(rdp); - } + for_each_cpu(cpu, rcu_nocb_mask) + init_nocb_callback_list(per_cpu_ptr(rsp->rda, cpu)); rcu_organize_nocb_kthreads(rsp); } } @@ -2534,6 +2524,16 @@ static bool init_nocb_callback_list(struct rcu_data *rdp) if (!rcu_is_nocb_cpu(rdp->cpu)) return false; + /* If there are early-boot callbacks, move them to nocb lists. */ + if (rdp->nxtlist) { + rdp->nocb_head = rdp->nxtlist; + rdp->nocb_tail = rdp->nxttail[RCU_NEXT_TAIL]; + atomic_long_set(&rdp->nocb_q_count, rdp->qlen); + atomic_long_set(&rdp->nocb_q_count_lazy, rdp->qlen_lazy); + rdp->nxtlist = NULL; + rdp->qlen = 0; + rdp->qlen_lazy = 0; + } rdp->nxttail[RCU_NEXT_TAIL] = NULL; return true; } -- 1.8.1.5
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