Re: [PATCH] kprobes: Fix to delay the kprobes jump optimization
From: Steven Rostedt
Date: Fri Feb 19 2021 - 15:03:22 EST
On Fri, 19 Feb 2021 10:33:36 -0800
"Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:
> commit 4f659bf04fc4610523544493d6db92fc8670b086
> Author: Paul E. McKenney <paulmck@xxxxxxxxxx>
> Date: Fri Feb 12 16:20:40 2021 -0800
>
> softirq: Don't try waking ksoftirqd before it has been spawned
>
> If there is heavy softirq activity, the softirq system will attempt
> to awaken ksoftirqd and will stop the traditional back-of-interrupt
> softirq processing. This is all well and good, but only if the
> ksoftirqd kthreads already exist, which is not the case during early
> boot, in which case the system hangs.
>
> One reproducer is as follows:
>
> tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 2 --configs "TREE03" --kconfig "CONFIG_DEBUG_LOCK_ALLOC=y CONFIG_PROVE_LOCKING=y" --bootargs "threadirqs=1" --trust-make
>
> This commit therefore adds a couple of existence checks for ksoftirqd
> and forces back-of-interrupt softirq processing when ksoftirqd does not
> yet exist. With this change, the above test passes.
>
> Reported-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> Reported-by: Uladzislau Rezki <urezki@xxxxxxxxx>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Hmm, I wonder if this is what patchwork picked up regarding the
reported-by.
And I checked, it did not add the "Signed-off-by" from you to Masami's
patch ;-)
The dangers of posting patches in threads of other patches :-/
-- Steve