From 09c7b890622d72b5e004cc249bbe610e8b928ddf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 8 Feb 2013 15:55:02 -0800 Subject: rcu: Add event tracing for no-CBs CPUs' grace periods Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- include/trace/events/rcu.h | 55 ++++++++++++++++++++++++++++++++++++++++++++++ kernel/rcutree_plugin.h | 30 +++++++++++++++++++++++++ 2 files changed, 85 insertions(+) diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h index 1918e832da4f..cdfed6d386eb 100644 --- a/include/trace/events/rcu.h +++ b/include/trace/events/rcu.h @@ -71,6 +71,58 @@ TRACE_EVENT(rcu_grace_period, __entry->rcuname, __entry->gpnum, __entry->gpevent) ); +/* + * 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: + * + * "Startleaf": Request a nocb grace period based on leaf-node data. + * "Startedleaf": Leaf-node start proved sufficient. + * "Startedleafroot": Leaf-node start proved sufficient after checking root. + * "Startedroot": Requested a nocb grace period based on root-node data. + * "StartWait": Start waiting for the requested grace period. + * "ResumeWait": Resume waiting after signal. + * "EndWait": Complete wait. + * "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, + + TP_PROTO(char *rcuname, unsigned long gpnum, unsigned long completed, + unsigned long c, u8 level, int grplo, int grphi, + char *gpevent), + + TP_ARGS(rcuname, gpnum, completed, c, level, grplo, grphi, gpevent), + + TP_STRUCT__entry( + __field(char *, rcuname) + __field(unsigned long, gpnum) + __field(unsigned long, completed) + __field(unsigned long, c) + __field(u8, level) + __field(int, grplo) + __field(int, grphi) + __field(char *, gpevent) + ), + + TP_fast_assign( + __entry->rcuname = rcuname; + __entry->gpnum = gpnum; + __entry->completed = completed; + __entry->c = c; + __entry->level = level; + __entry->grplo = grplo; + __entry->grphi = grphi; + __entry->gpevent = gpevent; + ), + + TP_printk("%s %lu %lu %lu %u %d %d %s", + __entry->rcuname, __entry->gpnum, __entry->completed, + __entry->c, __entry->level, __entry->grplo, __entry->grphi, + __entry->gpevent) +); + /* * Tracepoint for grace-period-initialization events. These are * distinguished by the type of RCU, the new grace-period number, the @@ -601,6 +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_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 7225a5a14cef..e32236e83dda 100644 --- a/kernel/rcutree_plugin.h +++ b/kernel/rcutree_plugin.h @@ -2201,6 +2201,9 @@ 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"); return needmore; } @@ -2347,6 +2350,9 @@ 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"); if (rnp->gpnum != rnp->completed) { @@ -2355,6 +2361,10 @@ 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"); raw_spin_unlock_irqrestore(&rnp->lock, flags); } else { @@ -2366,6 +2376,11 @@ 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"); raw_spin_unlock(&rnp_root->lock); /* irqs disabled. */ } else { @@ -2381,6 +2396,11 @@ 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"); local_save_flags(flags1); rcu_start_gp(rdp->rsp, flags1); /* Rlses ->lock. */ } @@ -2396,6 +2416,9 @@ 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"); for (;;) { wait_event_interruptible( rnp->nocb_gp_wq[c & 0x1], @@ -2403,7 +2426,14 @@ 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_nocb_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. */ } -- cgit v1.2.3