Re: [PATCH 4.14 023/159] mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y

[Dou Liyang]

Hi Kirill,Mike

At 02/07/2018 06:45 PM, Mike Galbraith wrote:
> On Wed, 2018-02-07 at 13:41 +0300, Kirill A. Shutemov wrote:
> > On Wed, Feb 07, 2018 at 05:25:05PM +0800, Dou Liyang wrote:
> > > Hi All,
> > >
> > > I met the makedumpfile failed in the upstream kernel which contained
> > > this patch. Did I missed something else?
> >
> > None I'm aware of.
> >
> > Is there a reason to suspect that the issue is related to the bug this patch
> > fixed?

I did a contrastive test by my colleagues Indoh's suggestion.

Revert your two commits:

commit 83e3c48729d9ebb7af5a31a504f3fd6aff0348c4
Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Date:   Fri Sep 29 17:08:16 2017 +0300

commit 629a359bdb0e0652a8227b4ff3125431995fec6e
Author: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Date:   Tue Nov 7 11:33:37 2017 +0300

...and keep others unchanged, the makedumpfile works well.

> Still works fine for me with .today.  Box is only 16GB desktop box though.
Btw, In the upstream kernel which contained this patch, I did two tests:

 1) use the makedumpfile as core_collector in /etc/kdump.conf, then
trigger the process of kdump by echo 1 >/proc/sysrq-trigger, the
makedumpfile works well and I can get the vmcore file.

     ......It is OK

 2) use cp as core_collector, do the same operation to get the vmcore 
file. then use makedumpfile to do like above:

    [douly@localhost code]$ ./makedumpfile -d 31 --message-level 31 -x
vmlinux_4.15+ vmcore_4.15+_from_cp_command vmcore_4.15+

    ......It causes makedumpfile failed.


Thanks,
	dou.

> 	-Mike