diff options
| -rw-r--r-- | include/trace/events/rcu.h | 38 | ||||
| -rw-r--r-- | kernel/rcutiny.c | 10 | ||||
| -rw-r--r-- | kernel/rcutiny_plugin.h | 25 | ||||
| -rw-r--r-- | kernel/rcutree.c | 8 |
4 files changed, 68 insertions, 13 deletions
diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h index c75418c3ccb8..d2d88bed891b 100644 --- a/include/trace/events/rcu.h +++ b/include/trace/events/rcu.h @@ -461,27 +461,46 @@ TRACE_EVENT(rcu_invoke_kfree_callback, /* * Tracepoint for exiting rcu_do_batch after RCU callbacks have been - * invoked. The first argument is the name of the RCU flavor and - * the second argument is number of callbacks actually invoked. + * invoked. The first argument is the name of the RCU flavor, + * the second argument is number of callbacks actually invoked, + * the third argument (cb) is whether or not any of the callbacks that + * were ready to invoke at the beginning of this batch are still + * queued, the fourth argument (nr) is the return value of need_resched(), + * the fifth argument (iit) is 1 if the current task is the idle task, + * and the sixth argument (risk) is the return value from + * rcu_is_callbacks_kthread(). */ TRACE_EVENT(rcu_batch_end, - TP_PROTO(char *rcuname, int callbacks_invoked), + TP_PROTO(char *rcuname, int callbacks_invoked, + bool cb, bool nr, bool iit, bool risk), - TP_ARGS(rcuname, callbacks_invoked), + TP_ARGS(rcuname, callbacks_invoked, cb, nr, iit, risk), TP_STRUCT__entry( __field(char *, rcuname) __field(int, callbacks_invoked) + __field(bool, cb) + __field(bool, nr) + __field(bool, iit) + __field(bool, risk) ), TP_fast_assign( __entry->rcuname = rcuname; __entry->callbacks_invoked = callbacks_invoked; - ), - - TP_printk("%s CBs-invoked=%d", - __entry->rcuname, __entry->callbacks_invoked) + __entry->cb = cb; + __entry->nr = nr; + __entry->iit = iit; + __entry->risk = risk; + ), + + TP_printk("%s CBs-invoked=%d idle=%c%c%c%c", + __entry->rcuname, __entry->callbacks_invoked, + __entry->cb ? 'C' : '.', + __entry->nr ? 'S' : '.', + __entry->iit ? 'I' : '.', + __entry->risk ? 'R' : '.') ); /* @@ -524,7 +543,8 @@ TRACE_EVENT(rcu_torture_read, #define trace_rcu_batch_start(rcuname, qlen, blimit) do { } while (0) #define trace_rcu_invoke_callback(rcuname, rhp) do { } while (0) #define trace_rcu_invoke_kfree_callback(rcuname, rhp, offset) do { } while (0) -#define trace_rcu_batch_end(rcuname, callbacks_invoked) do { } while (0) +#define trace_rcu_batch_end(rcuname, callbacks_invoked, cb, nr, iit, risk) \ + do { } while (0) #define trace_rcu_torture_read(rcutorturename, rhp) do { } while (0) #endif /* #else #ifdef CONFIG_RCU_TRACE */ diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index e5bd94954fa3..977296dca0a4 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -259,7 +259,11 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp) /* If no RCU callbacks ready to invoke, just return. */ if (&rcp->rcucblist == rcp->donetail) { RCU_TRACE(trace_rcu_batch_start(rcp->name, 0, -1)); - RCU_TRACE(trace_rcu_batch_end(rcp->name, 0)); + RCU_TRACE(trace_rcu_batch_end(rcp->name, 0, + ACCESS_ONCE(rcp->rcucblist), + need_resched(), + is_idle_task(current), + rcu_is_callbacks_kthread())); return; } @@ -288,7 +292,9 @@ static void __rcu_process_callbacks(struct rcu_ctrlblk *rcp) RCU_TRACE(cb_count++); } RCU_TRACE(rcu_trace_sub_qlen(rcp, cb_count)); - RCU_TRACE(trace_rcu_batch_end(rcp->name, cb_count)); + RCU_TRACE(trace_rcu_batch_end(rcp->name, cb_count, 0, need_resched(), + is_idle_task(current), + rcu_is_callbacks_kthread())); } static void rcu_process_callbacks(struct softirq_action *unused) diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h index 2b0484a5dc28..dfa97cbb3910 100644 --- a/kernel/rcutiny_plugin.h +++ b/kernel/rcutiny_plugin.h @@ -885,6 +885,19 @@ static void invoke_rcu_callbacks(void) wake_up(&rcu_kthread_wq); } +#ifdef CONFIG_RCU_TRACE + +/* + * Is the current CPU running the RCU-callbacks kthread? + * Caller must have preemption disabled. + */ +static bool rcu_is_callbacks_kthread(void) +{ + return rcu_kthread_task == current; +} + +#endif /* #ifdef CONFIG_RCU_TRACE */ + /* * This kthread invokes RCU callbacks whose grace periods have * elapsed. It is awakened as needed, and takes the place of the @@ -938,6 +951,18 @@ void invoke_rcu_callbacks(void) raise_softirq(RCU_SOFTIRQ); } +#ifdef CONFIG_RCU_TRACE + +/* + * There is no callback kthread, so this thread is never it. + */ +static bool rcu_is_callbacks_kthread(void) +{ + return false; +} + +#endif /* #ifdef CONFIG_RCU_TRACE */ + void rcu_init(void) { open_softirq(RCU_SOFTIRQ, rcu_process_callbacks); diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 2b2e1a996a65..6c4a6722abfd 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -1373,7 +1373,9 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp) /* If no callbacks are ready, just return.*/ if (!cpu_has_callbacks_ready_to_invoke(rdp)) { trace_rcu_batch_start(rsp->name, 0, 0); - trace_rcu_batch_end(rsp->name, 0); + trace_rcu_batch_end(rsp->name, 0, !!ACCESS_ONCE(rdp->nxtlist), + need_resched(), is_idle_task(current), + rcu_is_callbacks_kthread()); return; } @@ -1409,7 +1411,9 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp) } local_irq_save(flags); - trace_rcu_batch_end(rsp->name, count); + trace_rcu_batch_end(rsp->name, count, !!list, need_resched(), + is_idle_task(current), + rcu_is_callbacks_kthread()); /* Update count, and requeue any remaining callbacks. */ rdp->qlen -= count; |