diff options
| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2011-10-31 23:01:54 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2011-12-11 19:31:42 +0100 |
| commit | 4145fa7fbee3ec1e61c52825b146192885d9759f (patch) | |
| tree | 58e0767a59bf110acb99da3fb5c1f0f0b5170be8 /kernel/rcutiny.c | |
| parent | rcu: Add documentation for raw SRCU read-side primitives (diff) | |
| download | linux-4145fa7fbee3ec1e61c52825b146192885d9759f.tar.xz linux-4145fa7fbee3ec1e61c52825b146192885d9759f.zip | |
rcu: Deconfuse dynticks entry-exit tracing
The trace_rcu_dyntick() trace event did not print both the old and
the new value of the nesting level, and furthermore printed only
the low-order 32 bits of it. This could result in some confusion
when interpreting trace-event dumps, so this commit prints both
the old and the new value, prints the full 64 bits, and also selects
the process-entry/exit increment to print nicely in hexadecimal.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcutiny.c')
| -rw-r--r-- | kernel/rcutiny.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c index b4e0b4981768..9b9bdf666fb5 100644 --- a/kernel/rcutiny.c +++ b/kernel/rcutiny.c @@ -53,20 +53,21 @@ static void __call_rcu(struct rcu_head *head, #include "rcutiny_plugin.h" -static long long rcu_dynticks_nesting = LLONG_MAX / 2; +static long long rcu_dynticks_nesting = DYNTICK_TASK_NESTING; /* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcutree.c. */ -static void rcu_idle_enter_common(void) +static void rcu_idle_enter_common(long long oldval) { if (rcu_dynticks_nesting) { - RCU_TRACE(trace_rcu_dyntick("--=", rcu_dynticks_nesting)); + RCU_TRACE(trace_rcu_dyntick("--=", + oldval, rcu_dynticks_nesting)); return; } - RCU_TRACE(trace_rcu_dyntick("Start", rcu_dynticks_nesting)); + RCU_TRACE(trace_rcu_dyntick("Start", oldval, rcu_dynticks_nesting)); if (!idle_cpu(smp_processor_id())) { WARN_ON_ONCE(1); /* must be idle task! */ RCU_TRACE(trace_rcu_dyntick("Error on entry: not idle task", - rcu_dynticks_nesting)); + oldval, rcu_dynticks_nesting)); ftrace_dump(DUMP_ALL); } rcu_sched_qs(0); /* implies rcu_bh_qsctr_inc(0) */ @@ -79,10 +80,12 @@ static void rcu_idle_enter_common(void) void rcu_idle_enter(void) { unsigned long flags; + long long oldval; local_irq_save(flags); + oldval = rcu_dynticks_nesting; rcu_dynticks_nesting = 0; - rcu_idle_enter_common(); + rcu_idle_enter_common(oldval); local_irq_restore(flags); } @@ -92,11 +95,13 @@ void rcu_idle_enter(void) void rcu_irq_exit(void) { unsigned long flags; + long long oldval; local_irq_save(flags); + oldval = rcu_dynticks_nesting; rcu_dynticks_nesting--; WARN_ON_ONCE(rcu_dynticks_nesting < 0); - rcu_idle_enter_common(); + rcu_idle_enter_common(oldval); local_irq_restore(flags); } @@ -104,14 +109,15 @@ void rcu_irq_exit(void) static void rcu_idle_exit_common(long long oldval) { if (oldval) { - RCU_TRACE(trace_rcu_dyntick("++=", rcu_dynticks_nesting)); + RCU_TRACE(trace_rcu_dyntick("++=", + oldval, rcu_dynticks_nesting)); return; } - RCU_TRACE(trace_rcu_dyntick("End", oldval)); + RCU_TRACE(trace_rcu_dyntick("End", oldval, rcu_dynticks_nesting)); if (!idle_cpu(smp_processor_id())) { WARN_ON_ONCE(1); /* must be idle task! */ RCU_TRACE(trace_rcu_dyntick("Error on exit: not idle task", - oldval)); + oldval, rcu_dynticks_nesting)); ftrace_dump(DUMP_ALL); } } @@ -127,7 +133,7 @@ void rcu_idle_exit(void) local_irq_save(flags); oldval = rcu_dynticks_nesting; WARN_ON_ONCE(oldval != 0); - rcu_dynticks_nesting = LLONG_MAX / 2; + rcu_dynticks_nesting = DYNTICK_TASK_NESTING; rcu_idle_exit_common(oldval); local_irq_restore(flags); } |