Messages in this thread Patch in this message | | | From | "Joel Fernandes (Google)" <> | Subject | [PATCH RFC 3/3] locktorture: Make the rt_boost factor a tunable | Date | Wed, 23 Nov 2022 01:21:04 +0000 |
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The rt boosting in locktorture has a factor variable large enough that boosting only happens once every minute or so. Add a tunable to educe the factor so that boosting happens more often, to test paths and arrive at failure modes earlier. With this change, I can set the factor to like 50 and have the boosting happens every 10 seconds or so.
Tested with boot parameters: locktorture.torture_type=mutex_lock locktorture.onoff_interval=1 locktorture.nwriters_stress=8 locktorture.stutter=0 locktorture.rt_boost=1 locktorture.rt_boost_factor=50 locktorture.nlocks=3
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> --- kernel/locking/locktorture.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 5a388ac96a9b..e4529c2166e9 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -47,6 +47,7 @@ torture_param(int, stat_interval, 60, "Number of seconds between stats printk()s"); torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); torture_param(int, rt_boost, 0, "Perform an rt-boost from the writer, always 1 for rtmutex_lock"); +torture_param(int, rt_boost_factor, 50000, "A factor determining how often rt-boost happens"); torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); torture_param(int, nlocks, 1, @@ -132,15 +133,15 @@ static void torture_lock_busted_write_unlock(int tid __maybe_unused) static void torture_rt_boost(struct torture_random_state *trsp) { - const unsigned int factor = 50000; /* yes, quite arbitrary */ + const unsigned int factor = rt_boost_factor; /* yes, quite arbitrary */ if (!rt_boost) return; if (!rt_task(current)) { /* - * Boost priority once every ~50k operations. When the - * task tries to take the lock, the rtmutex it will account + * Boost priority once every rt_boost_factor operations. When + * the task tries to take the lock, the rtmutex it will account * for the new priority, and do any corresponding pi-dance. */ if (trsp && !(torture_random(trsp) % @@ -150,8 +151,9 @@ static void torture_rt_boost(struct torture_random_state *trsp) return; } else { /* - * The task will remain boosted for another ~500k operations, - * then restored back to its original prio, and so forth. + * The task will remain boosted for another 10*rt_boost_factor + * operations, then restored back to its original prio, and so + * forth. * * When @trsp is nil, we want to force-reset the task for * stopping the kthread. -- 2.38.1.584.g0f3c55d4c2-goog
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