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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-01-30 21:32:09 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-03-23 11:23:53 -0700 |
| commit | 718e2ff07466254a95c65525bd74b34d5a9c69fe (patch) | |
| tree | 4ce30f84a2a54d1e847b59077e469dbaf03b7c42 /kernel | |
| parent | 3f8ed616a42213f2eddb78530f033b8973aeb73b (diff) | |
| download | linux-next-718e2ff07466254a95c65525bd74b34d5a9c69fe.tar.gz | |
rcutorture: Avoid RCU CPU stall warning and RT throttling
Running rcuperf can result in RCU CPU stall warnings and RT throttling.
These occur because on of the real-time writer processes does
ftrace_dump() while still running at real-time priority. This commit
therefore prevents these problems by setting the writer thread back to
SCHED_NORMAL (AKA SCHED_OTHER) before doing ftrace_dump().
In addition, this commit adds a small fixed delay before dumping ftrace
buffer in order to decrease the probability that this dumping will
interfere with other writers' grace periods.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/rcuperf.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c index 4c08b4f440cc..1d88f1347301 100644 --- a/kernel/rcu/rcuperf.c +++ b/kernel/rcu/rcuperf.c @@ -404,11 +404,15 @@ rcu_perf_writer(void *arg) started = true; if (!done && i >= MIN_MEAS) { done = true; + sp.sched_priority = 0; + sched_setscheduler_nocheck(current, + SCHED_NORMAL, &sp); pr_alert("%s" PERF_FLAG "rcu_perf_writer %ld has %d measurements\n", perf_type, me, MIN_MEAS); if (atomic_inc_return(&n_rcu_perf_writer_finished) >= nrealwriters) { + schedule_timeout_interruptible(10); ftrace_dump(DUMP_ALL); PERFOUT_STRING("Test complete"); t_rcu_perf_writer_finished = t; |