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
