linux-kernel - Re: [PATCH 0/6] mm: make movable onlining suck less

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 4 Apr 2017 13:30:13 -0500
From:   Reza Arbab <arbab@...ux.vnet.ibm.com>
To:     Michal Hocko <mhocko@...nel.org>
Cc:     Mel Gorman <mgorman@...e.de>, linux-mm@...ck.org,
        Andrew Morton <akpm@...ux-foundation.org>,
        Vlastimil Babka <vbabka@...e.cz>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Yasuaki Ishimatsu <yasu.isimatu@...il.com>,
        Tang Chen <tangchen@...fujitsu.com>, qiuxishi@...wei.com,
        Kani Toshimitsu <toshi.kani@....com>, slaoub@...il.com,
        Joonsoo Kim <js1304@...il.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Zhang Zhen <zhenzhang.zhang@...wei.com>,
        David Rientjes <rientjes@...gle.com>,
        Daniel Kiper <daniel.kiper@...cle.com>,
        Igor Mammedov <imammedo@...hat.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        LKML <linux-kernel@...r.kernel.org>,
        Chris Metcalf <cmetcalf@...lanox.com>,
        Dan Williams <dan.j.williams@...il.com>,
        Heiko Carstens <heiko.carstens@...ibm.com>,
        Lai Jiangshan <laijs@...fujitsu.com>,
        Martin Schwidefsky <schwidefsky@...ibm.com>
Subject: Re: [PATCH 0/6] mm: make movable onlining suck less

On Tue, Apr 04, 2017 at 06:44:53PM +0200, Michal Hocko wrote:
>Thanks for your testing! This is highly appreciated.
>Can I assume your Tested-by?

Of course! Not quite done, though. I think I found another edge case.  
You get an oops when removing all of a node's memory:

__nr_to_section
__pfn_to_section
find_biggest_section_pfn
shrink_pgdat_span
__remove_zone
__remove_section
__remove_pages
arch_remove_memory
remove_memory

I stuck some debugging prints in, for context:

shrink_pgdat_span: start_pfn=0x10000, end_pfn=0x10100, pgdat_start_pfn=0x0, pgdat_end_pfn=0x20000
shrink_pgdat_span: start_pfn=0x10100, end_pfn=0x10200, pgdat_start_pfn=0x0, pgdat_end_pfn=0x20000
...%<...
shrink_pgdat_span: start_pfn=0x1fe00, end_pfn=0x1ff00, pgdat_start_pfn=0x0, pgdat_end_pfn=0x20000
shrink_pgdat_span: start_pfn=0x1ff00, end_pfn=0x20000, pgdat_start_pfn=0x0, pgdat_end_pfn=0x20000
find_biggest_section_pfn: start_pfn=0x0, end_pfn=0x1ff00
find_biggest_section_pfn loop: pfn=0x1feff, sec_nr = 0x1fe
find_biggest_section_pfn loop: pfn=0x1fdff, sec_nr = 0x1fd
...%<...
find_biggest_section_pfn loop: pfn=0x1ff, sec_nr = 0x1
find_biggest_section_pfn loop: pfn=0xff, sec_nr = 0x0
find_biggest_section_pfn loop: pfn=0xffffffffffffffff, sec_nr = 0xffffffffffffff
Unable to handle kernel paging request for data at address 0xc000800000f19e78

-- 
Reza Arbab