From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B34E34555 for ; Thu, 30 Nov 2023 12:22:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GGI2nGPI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21150C433C7; Thu, 30 Nov 2023 12:22:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1701346937; bh=gwb1GBCsOvRHdGI7B2sk516Lc3TuyoRMTLmOUTD6IZw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GGI2nGPIYKKd8tWoXxm0BcxkSPS09xrNN85hFWy3ZjE5uzF6oNcw1jBk2zHf7vj4w urKSfjKns5+gWnqGTzlE4bQtGjBFsLMvlD5rKxGmHeUIB9mNYRb7y8t8Vys9aYDe0r 9kYEWx20QyeGI+91wvfmox21LOjxorR0jLGvpw4Q= Date: Thu, 30 Nov 2023 12:22:14 +0000 From: Greg KH To: Ronald Monthero Cc: stable@vger.kernel.org Subject: Re: Backport submission - rcu: Avoid tracing a few functions executed in stop machine Message-ID: <2023113012-humorous-marshy-3060@gregkh> References: <2023112431-matching-imperfect-1b76@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, Nov 30, 2023 at 10:07:03PM +1000, Ronald Monthero wrote: > On Thu, Nov 30, 2023 at 12:08 AM Ronald Monthero > wrote: > > > > On Sat, Nov 25, 2023 at 2:10 AM Greg KH 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