diff options
author | Paul E. McKenney <paul.mckenney@linaro.org> | 2011-11-22 17:58:03 -0500 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2011-12-11 13:32:00 -0500 |
commit | 433cdddcd9ac5558068edd7f8d4707a70f7710f5 (patch) | |
tree | 7f3686eb64c9ee3a239e5920df588c70837c5637 /include | |
parent | 045fb9315a2129023d70a0eecf0942e18fca4fcd (diff) |
rcu: Add tracing for RCU_FAST_NO_HZ
This commit adds trace_rcu_prep_idle(), which is invoked from
rcu_prepare_for_idle() and rcu_wake_cpu() to trace attempts on
the part of RCU to force CPUs into dyntick-idle mode.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/trace/events/rcu.h | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h index 7f6877a35051..debe453c9623 100644 --- a/include/trace/events/rcu.h +++ b/include/trace/events/rcu.h | |||
@@ -275,6 +275,42 @@ TRACE_EVENT(rcu_dyntick, | |||
275 | ); | 275 | ); |
276 | 276 | ||
277 | /* | 277 | /* |
278 | * Tracepoint for RCU preparation for idle, the goal being to get RCU | ||
279 | * processing done so that the current CPU can shut off its scheduling | ||
280 | * clock and enter dyntick-idle mode. One way to accomplish this is | ||
281 | * to drain all RCU callbacks from this CPU, and the other is to have | ||
282 | * done everything RCU requires for the current grace period. In this | ||
283 | * latter case, the CPU will be awakened at the end of the current grace | ||
284 | * period in order to process the remainder of its callbacks. | ||
285 | * | ||
286 | * These tracepoints take a string as argument: | ||
287 | * | ||
288 | * "No callbacks": Nothing to do, no callbacks on this CPU. | ||
289 | * "In holdoff": Nothing to do, holding off after unsuccessful attempt. | ||
290 | * "Dyntick with callbacks": Callbacks remain, but RCU doesn't need CPU. | ||
291 | * "Begin holdoff": Attempt failed, don't retry until next jiffy. | ||
292 | * "More callbacks": Still more callbacks, try again to clear them out. | ||
293 | * "Callbacks drained": All callbacks processed, off to dyntick idle! | ||
294 | * "CPU awakened at GP end": | ||
295 | */ | ||
296 | TRACE_EVENT(rcu_prep_idle, | ||
297 | |||
298 | TP_PROTO(char *reason), | ||
299 | |||
300 | TP_ARGS(reason), | ||
301 | |||
302 | TP_STRUCT__entry( | ||
303 | __field(char *, reason) | ||
304 | ), | ||
305 | |||
306 | TP_fast_assign( | ||
307 | __entry->reason = reason; | ||
308 | ), | ||
309 | |||
310 | TP_printk("%s", __entry->reason) | ||
311 | ); | ||
312 | |||
313 | /* | ||
278 | * Tracepoint for the registration of a single RCU callback function. | 314 | * Tracepoint for the registration of a single RCU callback function. |
279 | * The first argument is the type of RCU, the second argument is | 315 | * The first argument is the type of RCU, the second argument is |
280 | * a pointer to the RCU callback itself, and the third element is the | 316 | * a pointer to the RCU callback itself, and the third element is the |
@@ -482,6 +518,7 @@ TRACE_EVENT(rcu_torture_read, | |||
482 | #define trace_rcu_quiescent_state_report(rcuname, gpnum, mask, qsmask, level, grplo, grphi, gp_tasks) do { } while (0) | 518 | #define trace_rcu_quiescent_state_report(rcuname, gpnum, mask, qsmask, level, grplo, grphi, gp_tasks) do { } while (0) |
483 | #define trace_rcu_fqs(rcuname, gpnum, cpu, qsevent) do { } while (0) | 519 | #define trace_rcu_fqs(rcuname, gpnum, cpu, qsevent) do { } while (0) |
484 | #define trace_rcu_dyntick(polarity, oldnesting, newnesting) do { } while (0) | 520 | #define trace_rcu_dyntick(polarity, oldnesting, newnesting) do { } while (0) |
521 | #define trace_rcu_prep_idle(reason) do { } while (0) | ||
485 | #define trace_rcu_callback(rcuname, rhp, qlen) do { } while (0) | 522 | #define trace_rcu_callback(rcuname, rhp, qlen) do { } while (0) |
486 | #define trace_rcu_kfree_callback(rcuname, rhp, offset, qlen) do { } while (0) | 523 | #define trace_rcu_kfree_callback(rcuname, rhp, offset, qlen) do { } while (0) |
487 | #define trace_rcu_batch_start(rcuname, qlen, blimit) do { } while (0) | 524 | #define trace_rcu_batch_start(rcuname, qlen, blimit) do { } while (0) |