Re: A few patches to consider

Atsushi Kumagai
2013-09-18T03:07:13Z

(2013/08/30 10:33), HATAYAMA Daisuke wrote:
> (2013/08/29 7:08), Cliff Wickman wrote:
>> From: Cliff Wickman <cpw@sgi.com>
>>
>> I am submitting 6 patches that I have found helpful in speeding the dump
>> process or clarifying the progress report.
>> They are not a series, and should not be interdependent. But if you
>> find any dependencies I apply them in this order:
>> [PATCH] makedumpfile: reverse -c and -p if using snappy compression
>> [PATCH] makedumpfile: use non-cyclic when possible
>> [PATCH] makedumpfile: shorten cyclic exclude-unnecessary passes
>> [PATCH] makedumpfile: shorten cyclic unnecessary-page scans
>> [PATCH] makedumpfile: show needed memory
>> [PATCH] makedumpfile: search for a debug vmlinux
>>
>> The last one (search for a debug vmlinux) is useful in identifying huge
>> pages with the PG_head/PG-tail flags. There was a patch from Petr Tesarik
>> that enables that huge page filtering. I don't think you are taking that one
>> as-is, but are reworking it. Seems like Hatayama-san was doing that work.
>
> No. If I have good memory, Kumagai-san was investigating how to integrate
> huge page filtering into current memory types currently supported by
> makedumpfile.

Yes, I was investigating it but I'm not working for it now.

I think main features should work without vmlinux,
but it was impossible about his patch as said by himself:

> This patch depends on exporting the relevant PG_* flags from the
> kernel (in VMCOREINFO), and that's where I got stuck, because depending
> on the number of available bits for the page flags, the kernel either
> has PG_head and PG_tail, or only PG_compound, so I needed a #ifdef, and
> the kernel maintainers didn't like the conditional.
> I can restart the discussion with kernel maintainers and see what I can do

Therefore, I waited that his work is finished and I was going to continue
my work, but I didn't say my thinking definitely, sorry.

Anyway, I should cooperate with Petr to develop huge page filtering,
so could you let me know the status of your work ?

Thanks
Atsushi Kumagai