On Fri, Feb 19, 2021 at 03:02:31PM -0500, Steven Rostedt wrote: > 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 :-/ Glad I asked, then! ;-) Thanx, Paul
