Hi Dave,
On Wednesday 22 March 2017 10:00 AM, Dave Young wrote:
On 03/21/17 at 10:18pm, Eric W. Biederman wrote:
Dave Young <dyo...@redhat.com> writes:
On 03/20/17 at 10:33pm, Eric W. Biederman wrote:
Xunlei Pang <xlp...@redhat.com> writes:
As Eric said,
"what we need to do is move the variable vmcoreinfo_note out
of the kernel's .bss section. And modify the code to regenerate
and keep this information in something like the control page.
Definitely something like this needs a page all to itself, and ideally
far away from any other kernel data structures. I clearly was not
watching closely the data someone decided to keep this silly thing
in the kernel's .bss section."
This patch allocates extra pages for these vmcoreinfo_XXX variables,
one advantage is that it enhances some safety of vmcoreinfo, because
vmcoreinfo now is kept far away from other kernel data structures.
Can you preceed this patch with a patch that removes CRASHTIME from
vmcoreinfo? If someone actually cares we can add a separate note that holds
a 64bit crashtime in the per cpu notes.
I think makedumpfile is using it, but I also vote to remove the
CRASHTIME. It is better not to do this while crashing and a makedumpfile
userspace patch is needed to drop the use of it.
As we are looking at reliability concerns removing CRASHTIME should make
everything in vmcoreinfo a boot time constant. Which should simplify
everything considerably.
It is a nice improvement..
We also need to take a close look at what s390 is doing with vmcoreinfo.
As apparently it is reading it in a different kind of crashdump process.
Yes, need careful review from s390 and maybe ppc64 especially about
patch 2/3, better to have comments from IBM about s390 dump tool and ppc
fadump. Added more cc.
w.r.t powerpc/fadump, this patch-set works fine..
Thanks
Hari
