rcu: Add tracing to rcu_gp_kthread() (63c4db78) · Commits · e / devices / android_kernel_xiaomi_markw

include/trace/events/rcu.h

+19 −9

Original line number	Original line	Diff line number	Diff line
	@@ -39,15 +39,25 @@ TRACE_EVENT(rcu_utilization,
	#if defined(CONFIG_TREE_RCU) \|\| defined(CONFIG_TREE_PREEMPT_RCU)		#if defined(CONFIG_TREE_RCU) \|\| defined(CONFIG_TREE_PREEMPT_RCU)

	/*		/*
	* Tracepoint for grace-period events: starting and ending a grace		* Tracepoint for grace-period events. Takes a string identifying the
	* period ("start" and "end", respectively), a CPU noting the start		* RCU flavor, the grace-period number, and a string identifying the
	* of a new grace period or the end of an old grace period ("cpustart"		* grace-period-related event as follows:
	* and "cpuend", respectively), a CPU passing through a quiescent		*
	* state ("cpuqs"), a CPU coming online or going offline ("cpuonl"		* "AccReadyCB": CPU acclerates new callbacks to RCU_NEXT_READY_TAIL.
	* and "cpuofl", respectively), a CPU being kicked for being too		* "AccWaitCB": CPU accelerates new callbacks to RCU_WAIT_TAIL.
	* long in dyntick-idle mode ("kick"), a CPU accelerating its new		* "start": Start a grace period.
	* callbacks to RCU_NEXT_READY_TAIL ("AccReadyCB"), and a CPU		* "cpustart": CPU first notices a grace-period start.
	* accelerating its new callbacks to RCU_WAIT_TAIL ("AccWaitCB").		* "cpuqs": CPU passes through a quiescent state.
			* "cpuonl": CPU comes online.
			* "cpuofl": CPU goes offline.
			* "reqwait": GP kthread sleeps waiting for grace-period request.
			* "reqwaitsig": GP kthread awakened by signal from reqwait state.
			* "fqswait": GP kthread waiting until time to force quiescent states.
			* "fqsstart": GP kthread starts forcing quiescent states.
			* "fqsend": GP kthread done forcing quiescent states.
			* "fqswaitsig": GP kthread awakened by signal from fqswait state.
			* "end": End a grace period.
			* "cpuend": CPU first notices a grace-period end.
	*/		*/
	TRACE_EVENT(rcu_grace_period,		TRACE_EVENT(rcu_grace_period,

kernel/rcutree.c

+18 −0

Original line number	Original line	Diff line number	Diff line
	@@ -1480,6 +1480,9 @@ static int __noreturn rcu_gp_kthread(void *arg)

	/* Handle grace-period start. */		/* Handle grace-period start. */
	for (;;) {		for (;;) {
			trace_rcu_grace_period(rsp->name,
			ACCESS_ONCE(rsp->gpnum),
			TPS("reqwait"));
	wait_event_interruptible(rsp->gp_wq,		wait_event_interruptible(rsp->gp_wq,
	ACCESS_ONCE(rsp->gp_flags) &		ACCESS_ONCE(rsp->gp_flags) &
	RCU_GP_FLAG_INIT);		RCU_GP_FLAG_INIT);
	@@ -1487,6 +1490,9 @@ static int __noreturn rcu_gp_kthread(void *arg)
	break;		break;
	cond_resched();		cond_resched();
	flush_signals(current);		flush_signals(current);
			trace_rcu_grace_period(rsp->name,
			ACCESS_ONCE(rsp->gpnum),
			TPS("reqwaitsig"));
	}		}

	/* Handle quiescent-state forcing. */		/* Handle quiescent-state forcing. */
	@@ -1500,6 +1506,9 @@ static int __noreturn rcu_gp_kthread(void *arg)
	for (;;) {		for (;;) {
	if (!ret)		if (!ret)
	rsp->jiffies_force_qs = jiffies + j;		rsp->jiffies_force_qs = jiffies + j;
			trace_rcu_grace_period(rsp->name,
			ACCESS_ONCE(rsp->gpnum),
			TPS("fqswait"));
	ret = wait_event_interruptible_timeout(rsp->gp_wq,		ret = wait_event_interruptible_timeout(rsp->gp_wq,
	((gf = ACCESS_ONCE(rsp->gp_flags)) &		((gf = ACCESS_ONCE(rsp->gp_flags)) &
	RCU_GP_FLAG_FQS) \|\|		RCU_GP_FLAG_FQS) \|\|
	@@ -1513,12 +1522,21 @@ static int __noreturn rcu_gp_kthread(void *arg)
	/* If time for quiescent-state forcing, do it. */		/* If time for quiescent-state forcing, do it. */
	if (ULONG_CMP_GE(jiffies, rsp->jiffies_force_qs) \|\|		if (ULONG_CMP_GE(jiffies, rsp->jiffies_force_qs) \|\|
	(gf & RCU_GP_FLAG_FQS)) {		(gf & RCU_GP_FLAG_FQS)) {
			trace_rcu_grace_period(rsp->name,
			ACCESS_ONCE(rsp->gpnum),
			TPS("fqsstart"));
	fqs_state = rcu_gp_fqs(rsp, fqs_state);		fqs_state = rcu_gp_fqs(rsp, fqs_state);
			trace_rcu_grace_period(rsp->name,
			ACCESS_ONCE(rsp->gpnum),
			TPS("fqsend"));
	cond_resched();		cond_resched();
	} else {		} else {
	/* Deal with stray signal. */		/* Deal with stray signal. */
	cond_resched();		cond_resched();
	flush_signals(current);		flush_signals(current);
			trace_rcu_grace_period(rsp->name,
			ACCESS_ONCE(rsp->gpnum),
			TPS("fqswaitsig"));
	}		}
	j = jiffies_till_next_fqs;		j = jiffies_till_next_fqs;
	if (j > HZ) {		if (j > HZ) {