Re: [PATCH 0/3] makedumpfile: hugepage filtering for vmcore dump
From: Jingbai Ma
Date: Thu Nov 07 2013 - 03:57:38 EST
On 11/06/2013 10:23 PM, Vivek Goyal wrote:
On Wed, Nov 06, 2013 at 02:21:39AM +0000, Atsushi Kumagai wrote:
(2013/11/06 5:27), Vivek Goyal wrote:
On Tue, Nov 05, 2013 at 09:45:32PM +0800, Jingbai Ma wrote:
This patch set intend to exclude unnecessary hugepages from vmcore dump file.
This patch requires the kernel patch to export necessary data structures into
vmcore: "kexec: export hugepage data structure into vmcoreinfo"
http://lists.infradead.org/pipermail/kexec/2013-November/009997.html
This patch introduce two new dump levels 32 and 64 to exclude all unused and
active hugepages. The level to exclude all unnecessary pages will be 127 now.
Interesting. Why hugepages should be treated any differentely than normal
pages?
If user asked to filter out free page, then it should be filtered and
it should not matter whether it is a huge page or not?
I'm making a RFC patch of hugepages filtering based on such policy.
I attach the prototype version.
It's able to filter out also THPs, and suitable for cyclic processing
because it depends on mem_map and looking up it can be divided into
cycles. This is the same idea as page_is_buddy().
So I think it's better.
Agreed. Being able to treat hugepages in same manner as other pages
sounds good.
Jingbai, looks good to you?
It looks good to me.
My only concern is by this way, we only can exclude all hugepage
together, but can't exclude the free hugepages only. I'm not sure if
user need to dump out the activated hugepage only.
Kumagai-san, please correct me, if I'm wrong.
Thanks
Vivek
--
Thanks
Atsushi Kumagai
--
Thanks,
Jingbai Ma
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