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Message-ID: <CALm+0cWeZx5sZ7JJ-xdYPfxP4fs905iMmvyNPLJRj+262FpiGg@mail.gmail.com>
Date: Wed, 10 Apr 2024 10:57:46 +0800
From: Z qiang <qiang.zhang1211@...il.com>
To: paulmck@...nel.org
Cc: frederic@...nel.org, neeraj.upadhyay@...nel.org, joel@...lfernandes.org,
rcu@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] rcutorture: Make rcutorture support srcu double call test
On Wed, Apr 10, 2024 at 4:05 AM Paul E. McKenney <paulmck@...nel.org> wrote:
>
> On Sun, Apr 07, 2024 at 07:27:14PM +0800, Zqiang wrote:
> > This commit also allows rcutorture to support srcu double call test
> > with CONFIG_DEBUG_OBJECTS_RCU_HEAD option enabled. the non-raw sdp
> > structure's->spinlock will be acquired in call_srcu(), in Preempt-RT
> > kernels, this spinlock is sleepable, therefore remove disable-irq and
> > disable-preempt protection.
> >
> > Signed-off-by: Zqiang <qiang.zhang1211@...il.com>
> > ---
> > kernel/rcu/rcutorture.c | 46 +++++++++++++++++++++++------------------
> > 1 file changed, 26 insertions(+), 20 deletions(-)
> >
> > diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
> > index 807fbf6123a7..44cc455e1b61 100644
> > --- a/kernel/rcu/rcutorture.c
> > +++ b/kernel/rcu/rcutorture.c
> > @@ -390,6 +390,7 @@ struct rcu_torture_ops {
> > int extendables;
> > int slow_gps;
> > int no_pi_lock;
> > + int debug_objects;
> > const char *name;
> > };
> >
> > @@ -577,6 +578,7 @@ static struct rcu_torture_ops rcu_ops = {
> > .irq_capable = 1,
> > .can_boost = IS_ENABLED(CONFIG_RCU_BOOST),
> > .extendables = RCUTORTURE_MAX_EXTEND,
> > + .debug_objects = 1,
> > .name = "rcu"
> > };
> >
> > @@ -747,6 +749,7 @@ static struct rcu_torture_ops srcu_ops = {
> > .cbflood_max = 50000,
> > .irq_capable = 1,
> > .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU),
> > + .debug_objects = 1,
> > .name = "srcu"
> > };
> >
> > @@ -786,6 +789,7 @@ static struct rcu_torture_ops srcud_ops = {
> > .cbflood_max = 50000,
> > .irq_capable = 1,
> > .no_pi_lock = IS_ENABLED(CONFIG_TINY_SRCU),
> > + .debug_objects = 1,
> > .name = "srcud"
> > };
> >
> > @@ -3455,7 +3459,6 @@ rcu_torture_cleanup(void)
> > cur_ops->gp_slow_unregister(NULL);
> > }
> >
> > -#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
> > static void rcu_torture_leak_cb(struct rcu_head *rhp)
> > {
> > }
> > @@ -3473,7 +3476,6 @@ static void rcu_torture_err_cb(struct rcu_head *rhp)
> > */
> > pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME);
> > }
> > -#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
> >
> > /*
> > * Verify that double-free causes debug-objects to complain, but only
> > @@ -3482,39 +3484,43 @@ static void rcu_torture_err_cb(struct rcu_head *rhp)
> > */
> > static void rcu_test_debug_objects(void)
> > {
> > -#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
> > struct rcu_head rh1;
> > struct rcu_head rh2;
> > + int idx;
> > +
> > + if (!IS_ENABLED(CONFIG_DEBUG_OBJECTS_RCU_HEAD)) {
> > + pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_%s()\n",
> > + KBUILD_MODNAME, cur_ops->name);
> > + return;
> > + }
> > +
> > + if (WARN_ON_ONCE(cur_ops->debug_objects &&
> > + (!cur_ops->call || !cur_ops->cb_barrier)))
> > + return;
> > +
> > struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
> >
> > init_rcu_head_on_stack(&rh1);
> > init_rcu_head_on_stack(&rh2);
> > - pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME);
> > + pr_alert("%s: WARN: Duplicate call_%s() test starting.\n", KBUILD_MODNAME, cur_ops->name);
> >
> > /* Try to queue the rh2 pair of callbacks for the same grace period. */
> > - preempt_disable(); /* Prevent preemption from interrupting test. */
> > - rcu_read_lock(); /* Make it impossible to finish a grace period. */
> > - call_rcu_hurry(&rh1, rcu_torture_leak_cb); /* Start grace period. */
> > - local_irq_disable(); /* Make it harder to start a new grace period. */
> > - call_rcu_hurry(&rh2, rcu_torture_leak_cb);
> > - call_rcu_hurry(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
> > + idx = cur_ops->readlock(); /* Make it impossible to finish a grace period. */
> > + cur_ops->call(&rh1, rcu_torture_leak_cb); /* Start grace period. */
> > + cur_ops->call(&rh2, rcu_torture_leak_cb);
> > + cur_ops->call(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
> > if (rhp) {
> > - call_rcu_hurry(rhp, rcu_torture_leak_cb);
> > - call_rcu_hurry(rhp, rcu_torture_err_cb); /* Another duplicate callback. */
> > + cur_ops->call(rhp, rcu_torture_leak_cb);
> > + cur_ops->call(rhp, rcu_torture_err_cb); /* Another duplicate callback. */
> > }
> > - local_irq_enable();
> > - rcu_read_unlock();
> > - preempt_enable();
> > + cur_ops->readunlock(idx);
> >
> > /* Wait for them all to get done so we can safely return. */
> > - rcu_barrier();
> > - pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME);
> > + cur_ops->cb_barrier();
> > + pr_alert("%s: WARN: Duplicate call_%s() test complete.\n", KBUILD_MODNAME, cur_ops->name);
>
> This will get us "call_srcud() test", but if there are complaints yet
> another string can be added to the nrcu_torture_ops structure.
>
> So I have queued this for testing and further review.
Thanks, Paul, I think I should add my test results, the attachment
is the test results :) .
Thanks
Zqiang
>
> Thanx, Paul
>
> > destroy_rcu_head_on_stack(&rh1);
> > destroy_rcu_head_on_stack(&rh2);
> > kfree(rhp);
> > -#else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
> > - pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME);
> > -#endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
> > }
> >
> > static void rcutorture_sync(void)
> > --
> > 2.17.1
> >
View attachment "srcud.txt" of type "text/plain" (29208 bytes)
View attachment "srcu.txt" of type "text/plain" (34766 bytes)
View attachment "rcu.txt" of type "text/plain" (30903 bytes)
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