On Mon, Mar 21, 2022 at 08:57:46AM -0700, Paul E. McKenney wrote: > On Mon, Mar 21, 2022 at 11:46:28PM +0800, Zhouyi Zhou wrote: > > Hi Paul and Willy > > > > I can reproduce the bug. Following is what I do: > > 1.1 git clone https://kernel.source.codeaurora.cn/pub/scm/linux/kernel/git/torvalds/linux.git > > 1.2 cd linux > > 1.3 cp http://154.223.142.244/20220321/config-20220321 to .config > > 1.4 make vmlinux -j 16 > > 1.5 kvm -smp 4 -net none -serial file:/tmp/console.log -m 512 > > -kernel vmlinux -append "console=ttyS0" > > 1.6 the /tmp/console.log is uploaded to > > http://154.223.142.244/20220321/console.log > > > > 2.1 wget https://kernel.source.codeaurora.cn/pub/scm/linux/kernel/git/torvalds/linux.git/snapshot/linux-5.17-rc6.tar.gz > > 2.2 - 2.6 the result is similar. > > > > I am very interested in this topic. > > Could you please give me about a week to make a full understand of the > > meaning of the warning, and try the fixes one by one, and > > find out what happens? > > Works for me! The eventual fix likely involves some version of Valentin > Schneider's patchset that provides APIs that allow RCU to detect the > current preemption state. Which can change at runtime. A prototype of > this patch is on -rcu here: > > 2436ee0b4cea ("EXP preempt/dynamic: Introduce preempt mode accessors") > > It is entirely possible that the fix might need to go to mainline sooner > rather than later. I guess it's possible to do that but that patch alone shouldn't fix anything. Also, what is the issue exactly? :-) I can't rewind far enough the conversation. Thanks.
