| Message ID | 20221213204839.321027-2-joel@joelfernandes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3,rcu/dev,1/2] locktorture: Allow non-rtmutex lock types to be boosted | expand |
On Tue, Dec 13, 2022 at 08:48:39PM +0000, Joel Fernandes (Google) wrote: > The rt boosting in locktorture has a factor variable s currently large enough > that boosting only happens once every minute or so. Add a tunable to reduce 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 > > [ Apply Davidlohr Bueso feedback on quoting rt_boost_factor. ] > > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Queued and pushed both, thank you both! I am not seeing any evidence of boot parameters being quoted in the kernel/locking directory, and I don't feel like I should be the one to be the first to push that convention into kernel/locking, so I left that change off. I don't have an opinion either way on it myself, aside from being more than a bit wary of the churn that would be required to impose this convention uniformly. Thanx, Paul > --- > 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 e2271e8fc302..87e861da0ad5 100644 > --- a/kernel/locking/locktorture.c > +++ b/kernel/locking/locktorture.c > @@ -48,6 +48,7 @@ torture_param(int, stat_interval, 60, > torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); > torture_param(int, rt_boost, 2, > "Do periodic rt-boost. 0=Disable, 1=Only for rt_mutex, 2=For all lock types."); > +torture_param(int, rt_boost_factor, 50, "A factor determining how often rt-boost happens."); > torture_param(int, verbose, 1, > "Enable verbose debugging printk()s"); > > @@ -131,12 +132,12 @@ 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; > > 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) % > @@ -146,8 +147,9 @@ 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. > -- > 2.39.0.314.g84b9a713c41-goog >
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index e2271e8fc302..87e861da0ad5 100644 --- a/kernel/locking/locktorture.c +++ b/kernel/locking/locktorture.c @@ -48,6 +48,7 @@ torture_param(int, stat_interval, 60, torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); torture_param(int, rt_boost, 2, "Do periodic rt-boost. 0=Disable, 1=Only for rt_mutex, 2=For all lock types."); +torture_param(int, rt_boost_factor, 50, "A factor determining how often rt-boost happens."); torture_param(int, verbose, 1, "Enable verbose debugging printk()s"); @@ -131,12 +132,12 @@ 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; 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) % @@ -146,8 +147,9 @@ 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.
The rt boosting in locktorture has a factor variable s currently large enough that boosting only happens once every minute or so. Add a tunable to reduce 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 [ Apply Davidlohr Bueso feedback on quoting rt_boost_factor. ] Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> --- kernel/locking/locktorture.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)