Messages in this thread | | | From | "Zhuo, Qiuxu" <> | Subject | RE: [PATCH v2] rcutorture: Convert schedule_timeout_uninterruptible() to mdelay() in rcu_torture_stall() | Date | Mon, 20 Mar 2023 08:48:35 +0000 |
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Hi Qiang,
> From: Zqiang <qiang1.zhang@intel.com> > Sent: Monday, March 20, 2023 11:24 AM > To: paulmck@kernel.org; frederic@kernel.org; joel@joelfernandes.org > Cc: rcu@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: [PATCH v2] rcutorture: Convert schedule_timeout_uninterruptible() > to mdelay() in rcu_torture_stall() > > For kernels built with enable PREEMPT_NONE and
s/enable/enabling/
> CONFIG_DEBUG_ATOMIC_SLEEP, running the RCU stall tests.
s/running/run
> > runqemu kvm slirp nographic qemuparams="-m 1024 -smp 4" > bootparams="nokaslr console=ttyS0 rcutorture.stall_cpu=30 > rcutorture.stall_no_softlockup=1 rcutorture.stall_cpu_irqsoff=1 > rcutorture.stall_cpu_block=1" -d > > [ 10.841071] rcu-torture: rcu_torture_stall begin CPU stall > [ 10.841073] rcu_torture_stall start on CPU 3. > [ 10.841077] BUG: scheduling while atomic: rcu_torture_sta/66/0x0000000 > .... > [ 10.841108] Call Trace: > [ 10.841110] <TASK> > [ 10.841112] dump_stack_lvl+0x64/0xb0 > [ 10.841118] dump_stack+0x10/0x20 > [ 10.841121] __schedule_bug+0x8b/0xb0 > [ 10.841126] __schedule+0x2172/0x2940 > [ 10.841157] schedule+0x9b/0x150 > [ 10.841160] schedule_timeout+0x2e8/0x4f0 > [ 10.841192] schedule_timeout_uninterruptible+0x47/0x50 > [ 10.841195] rcu_torture_stall+0x2e8/0x300 > [ 10.841199] kthread+0x175/0x1a0 > [ 10.841206] ret_from_fork+0x2c/0x50 > > The above calltrace occurs in the local_irq_disable/enable() critical section > call schedule_timeout(), and invoke schedule_timeout() also implies a > quiescent state, of course it also fails to trigger RCU stall, this commit > therefore use mdelay() instead of schedule_timeout() to trigger RCU stall.
Tweak the commit description above to fix some grammar errors:
The above call trace occurred in the local_irq_disable/enable() critical section when calling schedule_timeout() from rcu_torture_stall(). Invoking schedule_timeout() also implies a quiescent state, of course, it also fails to trigger RCU stall. This commit, therefore, uses mdelay() instead of schedule_timeout() to trigger the RCU stall.
> Suggested-by: Joel Fernandes <joel@joelfernandes.org> > Signed-off-by: Zqiang <qiang1.zhang@intel.com>
I didn't reproduce the call trace after applying your patch. So, with the above minor fixes, then
Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Thanks -Qiuxu
> --- > kernel/rcu/rcutorture.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index > d06c2da04c34..a08a72bef5f1 100644 > --- a/kernel/rcu/rcutorture.c > +++ b/kernel/rcu/rcutorture.c > @@ -2472,7 +2472,7 @@ static int rcu_torture_stall(void *args) #ifdef > CONFIG_PREEMPTION > preempt_schedule(); > #else > - schedule_timeout_uninterruptible(HZ); > + mdelay(jiffies_to_msecs(HZ)); > #endif > } else if (stall_no_softlockup) { > touch_softlockup_watchdog(); > -- > 2.25.1
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