Messages in this thread Patch in this message | | | Date | Thu, 12 Oct 2017 15:26:45 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH] tracing, rcu: Remove no longer used trace event rcu_prep_idle |
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On Thu, Oct 12, 2017 at 06:12:57PM -0400, Steven Rostedt wrote: > From: Steven Rostedt (VMware) <rostedt@goodmis.org> > > Commit c0f4dfd4f90 ("rcu: Make RCU_FAST_NO_HZ take advantage of > numbered callbacks") removed the only instances of trace_rcu_prep_idle, > but did not remove the TRACE_EVENT() that creates it. As defined trace > events take up memory within the kernel even when they are not used, > this is a waste of space. Remove the obsolete event. > > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Good catch, queued for review and testing, thank you!
Slight change in the context of the final hunk of the patch for -rcu, updated version shown below.
Thanx, Paul
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commit f9e1984a4a646537bc1c7bb1b86c57eb4906c468 Author: Steven Rostedt (VMware) <rostedt@goodmis.org> Date: Thu Oct 12 18:12:57 2017 -0400
tracing, rcu: Remove no longer used trace event rcu_prep_idle Commit c0f4dfd4f90 ("rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacks") removed the only instances of trace_rcu_prep_idle, but did not remove the TRACE_EVENT() that creates it. As defined trace events take up memory within the kernel even when they are not used, this is a waste of space. Remove the obsolete event. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h index 38069bbcc859..fe06b639f973 100644 --- a/include/trace/events/rcu.h +++ b/include/trace/events/rcu.h @@ -457,45 +457,6 @@ TRACE_EVENT(rcu_dyntick, ); /* - * Tracepoint for RCU preparation for idle, the goal being to get RCU - * processing done so that the current CPU can shut off its scheduling - * clock and enter dyntick-idle mode. One way to accomplish this is - * to drain all RCU callbacks from this CPU, and the other is to have - * done everything RCU requires for the current grace period. In this - * latter case, the CPU will be awakened at the end of the current grace - * period in order to process the remainder of its callbacks. - * - * These tracepoints take a string as argument: - * - * "No callbacks": Nothing to do, no callbacks on this CPU. - * "In holdoff": Nothing to do, holding off after unsuccessful attempt. - * "Begin holdoff": Attempt failed, don't retry until next jiffy. - * "Dyntick with callbacks": Entering dyntick-idle despite callbacks. - * "Dyntick with lazy callbacks": Entering dyntick-idle w/lazy callbacks. - * "More callbacks": Still more callbacks, try again to clear them out. - * "Callbacks drained": All callbacks processed, off to dyntick idle! - * "Timer": Timer fired to cause CPU to continue processing callbacks. - * "Demigrate": Timer fired on wrong CPU, woke up correct CPU. - * "Cleanup after idle": Idle exited, timer canceled. - */ -TRACE_EVENT(rcu_prep_idle, - - TP_PROTO(const char *reason), - - TP_ARGS(reason), - - TP_STRUCT__entry( - __field(const char *, reason) - ), - - TP_fast_assign( - __entry->reason = reason; - ), - - TP_printk("%s", __entry->reason) -); - -/* * Tracepoint for the registration of a single RCU callback function. * The first argument is the type of RCU, the second argument is * a pointer to the RCU callback itself, the third element is the @@ -802,7 +763,6 @@ TRACE_EVENT(rcu_barrier, while (0) #define trace_rcu_fqs(rcuname, gpnum, cpu, qsevent) do { } while (0) #define trace_rcu_dyntick(polarity, oldnesting, newnesting, dyntick) do { } while (0) -#define trace_rcu_prep_idle(reason) do { } while (0) #define trace_rcu_callback(rcuname, rhp, qlen_lazy, qlen) do { } while (0) #define trace_rcu_kfree_callback(rcuname, rhp, offset, qlen_lazy, qlen) \ do { } while (0)
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