/proc/vmcore mmap() failure issue
vgoyal at redhat.com
Fri Nov 15 09:26:17 EST 2013
On Fri, Nov 15, 2013 at 06:41:52PM +0900, HATAYAMA Daisuke wrote:
> >Given the fact that hpa does not like fixing it in kernel. We are left
> >with option of fixing it in following places.
> >- Drop partial pages in kexec-tools
> >- Drop partial pages in makeudmpfile.
> >- Read partial pages using read() interface in makedumpfile
> >- Modify /proc/vmcore to copy partial pages in second kernel's memory.
> >It is not clear to me that partial pages are really useful. So I want
> >to avoid modifying /proc/vmcore to deal with partial pages and increase
> >So fixing makedumpfile (either option2 or option 3) seems least risky
> >to me. In fact I would say let us keep it simple and truncate partial
> >pages in makedumpfile to keep it simple. And look at option 3 once we
> >have a strong use case for partial pages.
> >What do you think?
> As you say, it's not clear that partial pages are really useful, but on
> the other hand, it seems to me not clear that they are really useless.
> I think we should get them as long as we have access to them.
> It seems best to me the option 3). Switching between read and mmap would
> be not so complex and also it's by far flexible in makedumpfile than in
Ok, I am fine with option 3. It is more complicated option but safe
Is there any chance that you could look into fixing this. I have no
experience writing code for makedumpfile.
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