From 01c495f72a3b5a210e5689deba1ef33c82e8aa30 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 10 Jan 2018 12:36:00 -0800 Subject: [PATCH] rcu: Remove obsolete __rcu_pending() statistics for debugfs The debugfs interface displayed statistics on RCU-pending checks but this interface has since been removed. This commit therefore removes the no-longer-used rcu_data structure's ->n_rcu_pending, ->n_rp_core_needs_qs, ->n_rp_report_qs, ->n_rp_cb_ready, ->n_rp_cpu_needs_gp, ->n_rp_gp_completed, ->n_rp_gp_started, ->n_rp_nocb_defer_wakeup, and ->n_rp_need_nothing fields along with their updates. If this information proves necessary in the future, the corresponding event traces will be added. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 31 ++++++------------------------- kernel/rcu/tree.h | 17 +++-------------- 2 files changed, 9 insertions(+), 39 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 8e0711954bbf..99d59be761d1 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3354,8 +3354,6 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp) { struct rcu_node *rnp = rdp->mynode; - rdp->n_rcu_pending++; - /* Check for CPU stalls, if enabled. */ check_cpu_stall(rsp, rdp); @@ -3364,48 +3362,31 @@ static int __rcu_pending(struct rcu_state *rsp, struct rcu_data *rdp) return 0; /* Is the RCU core waiting for a quiescent state from this CPU? */ - if (rcu_scheduler_fully_active && - rdp->core_needs_qs && rdp->cpu_no_qs.b.norm && - rdp->rcu_qs_ctr_snap == __this_cpu_read(rcu_dynticks.rcu_qs_ctr)) { - rdp->n_rp_core_needs_qs++; - } else if (rdp->core_needs_qs && !rdp->cpu_no_qs.b.norm) { - rdp->n_rp_report_qs++; + if (rdp->core_needs_qs && !rdp->cpu_no_qs.b.norm) return 1; - } /* Does this CPU have callbacks ready to invoke? */ - if (rcu_segcblist_ready_cbs(&rdp->cblist)) { - rdp->n_rp_cb_ready++; + if (rcu_segcblist_ready_cbs(&rdp->cblist)) return 1; - } /* Has RCU gone idle with this CPU needing another grace period? */ - if (cpu_needs_another_gp(rsp, rdp)) { - rdp->n_rp_cpu_needs_gp++; + if (cpu_needs_another_gp(rsp, rdp)) return 1; - } /* Has another RCU grace period completed? */ - if (READ_ONCE(rnp->completed) != rdp->completed) { /* outside lock */ - rdp->n_rp_gp_completed++; + if (READ_ONCE(rnp->completed) != rdp->completed) /* outside lock */ return 1; - } /* Has a new RCU grace period started? */ if (READ_ONCE(rnp->gpnum) != rdp->gpnum || - unlikely(READ_ONCE(rdp->gpwrap))) { /* outside lock */ - rdp->n_rp_gp_started++; + unlikely(READ_ONCE(rdp->gpwrap))) /* outside lock */ return 1; - } /* Does this CPU need a deferred NOCB wakeup? */ - if (rcu_nocb_need_deferred_wakeup(rdp)) { - rdp->n_rp_nocb_defer_wakeup++; + if (rcu_nocb_need_deferred_wakeup(rdp)) return 1; - } /* nothing to do */ - rdp->n_rp_need_nothing++; return 0; } diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index b258fac73524..d29bab8dea28 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -226,18 +226,7 @@ struct rcu_data { /* Grace period that needs help */ /* from cond_resched(). */ - /* 5) __rcu_pending() statistics. */ - unsigned long n_rcu_pending; /* rcu_pending() calls since boot. */ - unsigned long n_rp_core_needs_qs; - unsigned long n_rp_report_qs; - unsigned long n_rp_cb_ready; - unsigned long n_rp_cpu_needs_gp; - unsigned long n_rp_gp_completed; - unsigned long n_rp_gp_started; - unsigned long n_rp_nocb_defer_wakeup; - unsigned long n_rp_need_nothing; - - /* 6) _rcu_barrier(), OOM callbacks, and expediting. */ + /* 5) _rcu_barrier(), OOM callbacks, and expediting. */ struct rcu_head barrier_head; #ifdef CONFIG_RCU_FAST_NO_HZ struct rcu_head oom_head; @@ -248,7 +237,7 @@ struct rcu_data { atomic_long_t exp_workdone3; /* # done by others #3. */ int exp_dynticks_snap; /* Double-check need for IPI. */ - /* 7) Callback offloading. */ + /* 6) Callback offloading. */ #ifdef CONFIG_RCU_NOCB_CPU struct rcu_head *nocb_head; /* CBs waiting for kthread. */ struct rcu_head **nocb_tail; @@ -275,7 +264,7 @@ struct rcu_data { /* Leader CPU takes GP-end wakeups. */ #endif /* #ifdef CONFIG_RCU_NOCB_CPU */ - /* 8) RCU CPU stall data. */ + /* 7) RCU CPU stall data. */ unsigned int softirq_snap; /* Snapshot of softirq activity. */ /* ->rcu_iw* fields protected by leaf rcu_node ->lock. */ struct irq_work rcu_iw; /* Check for non-irq activity. */