[PATCH v3 3/3] printk: use the lockless ringbuffer

John Ogness john.ogness at linutronix.de
Thu Jul 2 05:02:02 EDT 2020


On 2020-07-02, lijiang <lijiang at redhat.com> wrote:
> About the VMCOREINFO part, I made some tests based on the kernel patch
> v3, the makedumpfile and crash-utility can work as expected with your
> patch(userspace patch), but, unfortunately, the vmcore-dmesg(kexec-tools)
> can't correctly read the printk ring buffer information, and get the
> following error:
>
> "Missing the log_buf symbol"
>
> The kexec-tools(vmcore-dmesg) should also have a similar patch, just like
> in the makedumpfile and crash-utility.

Yes, a patch for this is needed (as well as for any other related
software floating around the internet).

I have no RFC patches for vmcore-dmesg. Looking at the code, I think it
would be quite straight forward to port the makedumpfile patch. I will
try to make some time for this.

I do not want to patch any other software for this. I think with 3
examples (crash, makedumpfile, vmcore-dmesg), others should be able to
implement the changes to their software without needing my help.

John Ogness



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