On Thu, Nov 30, 2023 at 10:07:03PM +1000, Ronald Monthero wrote:
On Thu, Nov 30, 2023 at 12:08 AM Ronald Monthero debug.penguin32@gmail.com wrote:
On Sat, Nov 25, 2023 at 2:10 AM Greg KH gregkh@linuxfoundation.org wrote:
On Tue, Nov 21, 2023 at 12:09:38AM +1000, Ronald Monthero wrote:
Dear stable maintainers, I like to indicate the oops encountered and request the below patch to be backported to v 5.15. The fix is important to avoid recurring oops in context of rcu detected stalls.
subject: rcu: Avoid tracing a few functions executed in stop machine commit 48f8070f5dd8 Target kernel version v 5.15 Reason for Application: To avoid oops due to rcu_prempt detect stalls on cpus/tasks
Environment and oops context: Issue was observed in my environment on 5.15.193 kernel (arm platform). The patch is helpful to avoid the below oops indicated in [1] and [2]
As the patch does not apply cleanly, we need a working and tested backport so we know to apply the correct version.
Can you please provide that as you've obviously already done this?
Hi Greg, Sorry I notice my typo error 193 instead of 93. I have tested on the 5.15.93-rt58 kernel.
Hi Greg, I used a 5.15.93 kernel
- on arm32 bit platform I tested with 5.15.93-rt58 (rt kernel) , on
real hardware - Freescale LS1021A, 32 bit Cortex A7 processor
- on x86_64 platform I tested non rt kernel 5.15.93 - virtual
machine - qemu platform
Below is the build log after patch to kernel/rcu/tree.h on x86_64
linux-5.15.93$ make CALL scripts/checksyscalls.sh CALL scripts/atomic/check-atomics.sh DESCEND objtool DESCEND bpf/resolve_btfids CHK include/generated/compile.h CC kernel/rcu/tree.o <<< AR kernel/rcu/built-in.a <<< AR kernel/built-in.a CHK kernel/kheaders_data.tar.xz GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o AR init/built-in.a LD vmlinux.o MODPOST vmlinux.symvers MODINFO modules.builtin.modinfo GEN modules.builtin LD .tmp_vmlinux.btf BTF .btf.vmlinux.bin.o LD .tmp_vmlinux.kallsyms1
< snipped >
BTF [M] sound/usb/usx2y/snd-usb-usx2y.ko BTF [M] sound/virtio/virtio_snd.ko BTF [M] sound/x86/snd-hdmi-lpe-audio.ko BTF [M] sound/xen/snd_xen_front.ko BTF [M] virt/lib/irqbypass.ko linux-5.15.93$
I don't understand what you are showing here, sorry.
I do not have a working backport anywhere that I can see, that is what we need. As you seem to have one, can you please submit it?
Also note, if you are using the -rt kernel, that changes lots of stuff that we know nothing about, please work with the -rt kernel developers about that.
thanks,
greg k-h