From bd9f0686fc8c9a01c6850b1c611d1c9ad80b86d6 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 29 Dec 2012 21:51:20 -0800 Subject: [PATCH] rcu: Repurpose no-CBs event tracing to future-GP events Dyntick-idle CPUs need to be able to pre-announce their need for grace periods. This can be done using something similar to the mechanism used by no-CB CPUs to announce their need for grace periods. This commit moves in this direction by renaming the no-CBs grace-period event tracing to suit the new future-grace-period needs. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- include/trace/events/rcu.h | 16 +++++----- kernel/rcutree_plugin.h | 62 ++++++++++++++++++++------------------ 2 files changed, 40 insertions(+), 38 deletions(-) diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h index cdfed6d386eb..59ebcc89f148 100644 --- a/include/trace/events/rcu.h +++ b/include/trace/events/rcu.h @@ -72,10 +72,10 @@ TRACE_EVENT(rcu_grace_period, ); /* - * Tracepoint for no-callbacks grace-period events. The caller should - * pull the data from the rcu_node structure, other than rcuname, which - * comes from the rcu_state structure, and event, which is one of the - * following: + * Tracepoint for future grace-period events, including those for no-callbacks + * CPUs. The caller should pull the data from the rcu_node structure, + * other than rcuname, which comes from the rcu_state structure, and event, + * which is one of the following: * * "Startleaf": Request a nocb grace period based on leaf-node data. * "Startedleaf": Leaf-node start proved sufficient. @@ -87,7 +87,7 @@ TRACE_EVENT(rcu_grace_period, * "Cleanup": Clean up rcu_node structure after previous GP. * "CleanupMore": Clean up, and another no-CB GP is needed. */ -TRACE_EVENT(rcu_nocb_grace_period, +TRACE_EVENT(rcu_future_grace_period, TP_PROTO(char *rcuname, unsigned long gpnum, unsigned long completed, unsigned long c, u8 level, int grplo, int grphi, @@ -653,9 +653,9 @@ TRACE_EVENT(rcu_barrier, #define trace_rcu_grace_period(rcuname, gpnum, gpevent) do { } while (0) #define trace_rcu_grace_period_init(rcuname, gpnum, level, grplo, grphi, \ qsmask) do { } while (0) -#define trace_rcu_nocb_grace_period(rcuname, gpnum, completed, c, \ - level, grplo, grphi, event) \ - do { } while (0) +#define trace_rcu_future_grace_period(rcuname, gpnum, completed, c, \ + level, grplo, grphi, event) \ + do { } while (0) #define trace_rcu_preempt_task(rcuname, pid, gpnum) do { } while (0) #define trace_rcu_unlock_preempted_task(rcuname, gpnum, pid) do { } while (0) #define trace_rcu_quiescent_state_report(rcuname, gpnum, mask, qsmask, level, \ diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index d318f9f18be5..df50502eca2c 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -2034,9 +2034,9 @@ static int rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp) wake_up_all(&rnp->nocb_gp_wq[c & 0x1]); rnp->n_nocb_gp_requests[c & 0x1] = 0; needmore = rnp->n_nocb_gp_requests[(c + 1) & 0x1]; - trace_rcu_nocb_grace_period(rsp->name, rnp->gpnum, rnp->completed, - c, rnp->level, rnp->grplo, rnp->grphi, - needmore ? "CleanupMore" : "Cleanup"); + trace_rcu_future_grace_period(rsp->name, rnp->gpnum, rnp->completed, + c, rnp->level, rnp->grplo, rnp->grphi, + needmore ? "CleanupMore" : "Cleanup"); return needmore; } @@ -2183,9 +2183,9 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp) /* Count our request for a grace period. */ rnp->n_nocb_gp_requests[c & 0x1]++; - trace_rcu_nocb_grace_period(rdp->rsp->name, rnp->gpnum, rnp->completed, - c, rnp->level, rnp->grplo, rnp->grphi, - "Startleaf"); + trace_rcu_future_grace_period(rdp->rsp->name, rnp->gpnum, + rnp->completed, c, rnp->level, + rnp->grplo, rnp->grphi, "Startleaf"); if (rnp->gpnum != rnp->completed) { @@ -2194,10 +2194,10 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp) * is in progress, so we are done. When this grace * period ends, our request will be acted upon. */ - trace_rcu_nocb_grace_period(rdp->rsp->name, - rnp->gpnum, rnp->completed, c, - rnp->level, rnp->grplo, rnp->grphi, - "Startedleaf"); + trace_rcu_future_grace_period(rdp->rsp->name, rnp->gpnum, + rnp->completed, c, rnp->level, + rnp->grplo, rnp->grphi, + "Startedleaf"); raw_spin_unlock_irqrestore(&rnp->lock, flags); } else { @@ -2209,11 +2209,12 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp) if (rnp != rnp_root) raw_spin_lock(&rnp_root->lock); /* irqs disabled. */ if (rnp_root->gpnum != rnp_root->completed) { - trace_rcu_nocb_grace_period(rdp->rsp->name, - rnp->gpnum, rnp->completed, - c, rnp->level, - rnp->grplo, rnp->grphi, - "Startedleafroot"); + trace_rcu_future_grace_period(rdp->rsp->name, + rnp->gpnum, + rnp->completed, + c, rnp->level, + rnp->grplo, rnp->grphi, + "Startedleafroot"); raw_spin_unlock(&rnp_root->lock); /* irqs disabled. */ } else { @@ -2229,11 +2230,12 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp) c = rnp_root->completed + 1; rnp->n_nocb_gp_requests[c & 0x1]++; rnp_root->n_nocb_gp_requests[c & 0x1]++; - trace_rcu_nocb_grace_period(rdp->rsp->name, - rnp->gpnum, rnp->completed, - c, rnp->level, - rnp->grplo, rnp->grphi, - "Startedroot"); + trace_rcu_future_grace_period(rdp->rsp->name, + rnp->gpnum, + rnp->completed, + c, rnp->level, + rnp->grplo, rnp->grphi, + "Startedroot"); local_save_flags(flags1); rcu_start_gp(rdp->rsp, flags1); /* Rlses ->lock. */ } @@ -2249,9 +2251,9 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp) * Wait for the grace period. Do so interruptibly to avoid messing * up the load average. */ - trace_rcu_nocb_grace_period(rdp->rsp->name, rnp->gpnum, rnp->completed, - c, rnp->level, rnp->grplo, rnp->grphi, - "StartWait"); + trace_rcu_future_grace_period(rdp->rsp->name, rnp->gpnum, + rnp->completed, c, rnp->level, + rnp->grplo, rnp->grphi, "StartWait"); for (;;) { wait_event_interruptible( rnp->nocb_gp_wq[c & 0x1], @@ -2259,14 +2261,14 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp) if (likely(d)) break; flush_signals(current); - trace_rcu_nocb_grace_period(rdp->rsp->name, - rnp->gpnum, rnp->completed, c, - rnp->level, rnp->grplo, rnp->grphi, - "ResumeWait"); + trace_rcu_future_grace_period(rdp->rsp->name, + rnp->gpnum, rnp->completed, c, + rnp->level, rnp->grplo, + rnp->grphi, "ResumeWait"); } - trace_rcu_nocb_grace_period(rdp->rsp->name, rnp->gpnum, rnp->completed, - c, rnp->level, rnp->grplo, rnp->grphi, - "EndWait"); + trace_rcu_future_grace_period(rdp->rsp->name, rnp->gpnum, + rnp->completed, c, rnp->level, + rnp->grplo, rnp->grphi, "EndWait"); smp_mb(); /* Ensure that CB invocation happens after GP end. */ }