| Message ID | 20221209022305.321149-2-joel@joelfernandes.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2,1/2] locktorture: Allow non-rtmutex lock types to be boosted | expand |
On Fri, 09 Dec 2022, 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 > >Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> >--- > 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 8968fd65a90d..b64a528e511c 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"); > torture_param(int, nlocks, 1, >@@ -133,12 +134,12 @@ 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 Nit: maybe refer to it as 'rt_boost_factor'? > * for the new priority, and do any corresponding pi-dance. > */ > if (trsp && !(torture_random(trsp) % >@@ -148,8 +149,9 @@ 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.rc1.256.g54fd8350bd-goog >
On Fri, Dec 9, 2022 at 5:02 PM Davidlohr Bueso <dave@stgolabs.net> wrote: > > On Fri, 09 Dec 2022, 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 > > > >Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> > > Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Thank you! > >--- > > 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 8968fd65a90d..b64a528e511c 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"); > > torture_param(int, nlocks, 1, > >@@ -133,12 +134,12 @@ 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 > > Nit: maybe refer to it as 'rt_boost_factor'? Sorry, I did not follow. Refer to what? thanks, - Joel > > > * for the new priority, and do any corresponding pi-dance. > > */ > > if (trsp && !(torture_random(trsp) % > >@@ -148,8 +149,9 @@ 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.rc1.256.g54fd8350bd-goog > >
On Fri, 09 Dec 2022, Joel Fernandes wrote: >> >- * 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 >> >> Nit: maybe refer to it as 'rt_boost_factor'? > >Sorry, I did not follow. Refer to what? Just use single quotes to refer to the parameter. Thanks, Davidlohr
On Fri, Dec 9, 2022 at 10:56 PM Davidlohr Bueso <dave@stgolabs.net> wrote: > > On Fri, 09 Dec 2022, Joel Fernandes wrote: > > >> >- * 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 > >> > >> Nit: maybe refer to it as 'rt_boost_factor'? > > > >Sorry, I did not follow. Refer to what? > > Just use single quotes to refer to the parameter. Ah, got it. Will do (either next respin or Paul can do it) and thank you. - Joel
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c index 8968fd65a90d..b64a528e511c 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"); torture_param(int, nlocks, 1, @@ -133,12 +134,12 @@ 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) % @@ -148,8 +149,9 @@ 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 Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> --- kernel/locking/locktorture.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)