Messages in this thread | | | Date | Sat, 17 Aug 2013 19:54:20 -0700 | From | Josh Triplett <> | Subject | Re: [PATCH tip/core/rcu 1/5] rcu: Add duplicate-callback tests to rcutorture |
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On Sat, Aug 17, 2013 at 07:25:13PM -0700, Paul E. McKenney wrote: > From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> > > This commit adds a object_debug option to rcutorture to allow the > debug-object-based checks for duplicate call_rcu() invocations to > be deterministically tested. > > Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> > Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> > Cc: Sedat Dilek <sedat.dilek@gmail.com> > Cc: Davidlohr Bueso <davidlohr.bueso@hp.com> > Cc: Rik van Riel <riel@surriel.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Two comments below; with those fixed, Reviewed-by: Josh Triplett <josh@joshtriplett.org>
> --- > @@ -100,6 +101,8 @@ module_param(fqs_stutter, int, 0444); > MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)"); > module_param(n_barrier_cbs, int, 0444); > MODULE_PARM_DESC(n_barrier_cbs, "# of callbacks/kthreads for barrier testing"); > +module_param(object_debug, int, 0444); > +MODULE_PARM_DESC(object_debug, "Enable debug-object double call_rcu() testing");
modules-next has a change to ignore and warn about unknown module parameters. Thus, I'd suggest wrapping the ifdef around this module parameter, so it doesn't exist at all without CONFIG_DEBUG_OBJECTS_RCU_HEAD.
Alternatively, consider providing the test unconditionally, and just printing a big warning message saying that it's going to cause corruption in the !CONFIG_DEBUG_OBJECTS_RCU_HEAD case.
> @@ -2163,6 +2178,28 @@ rcu_torture_init(void) > firsterr = retval; > goto unwind; > } > + if (object_debug) { > +#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD > + struct rcu_head rh1; > + struct rcu_head rh2; > + > + init_rcu_head_on_stack(&rh1); > + init_rcu_head_on_stack(&rh2); > + pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n"); > + local_irq_disable(); /* Make it hard to finish grace period. */ > + call_rcu(&rh1, rcu_torture_leak_cb); /* start grace period. */ > + call_rcu(&rh2, rcu_torture_err_cb); > + call_rcu(&rh2, rcu_torture_err_cb); /* duplicate callback. */ > + local_irq_enable(); > + rcu_barrier(); > + pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n"); > + destroy_rcu_head_on_stack(&rh1); > + destroy_rcu_head_on_stack(&rh2); > +#else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ > + pr_alert("rcutorture: !%s, not testing duplicate call_rcu()\n", > + "CONFIG_DEBUG_OBJECTS_RCU_HEAD");
Why put this parameter in a separate string? That makes it harder to grep for the full error message. (That's assuming you keep the error message, given the comment above.)
- Josh Triplett
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