Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-30 Thread David Hildenbrand
On 26.07.2018 21:50, Andrew Morton wrote: > On Thu, 26 Jul 2018 10:45:54 +0200 David Hildenbrand wrote: > >>> Does each user of PG_balloon check for PG_reserved? If this is the case >>> then yes this would be OK. >>> >> >> I can only spot one user of PageBalloon() at all (fs/proc/page.c) , >> whi

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-26 Thread Andrew Morton
On Thu, 26 Jul 2018 10:45:54 +0200 David Hildenbrand wrote: > > Does each user of PG_balloon check for PG_reserved? If this is the case > > then yes this would be OK. > > > > I can only spot one user of PageBalloon() at all (fs/proc/page.c) , > which makes me wonder if this bit is actually stil

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-26 Thread David Hildenbrand
On 26.07.2018 10:30, Michal Hocko wrote: > On Thu 26-07-18 10:22:41, David Hildenbrand wrote: >> On 24.07.2018 09:22, Michal Hocko wrote: >>> On Mon 23-07-18 19:12:58, David Hildenbrand wrote: On 23.07.2018 13:45, Vlastimil Babka wrote: > On 07/20/2018 02:34 PM, David Hildenbrand wrote: >>

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-26 Thread David Hildenbrand
On 26.07.2018 10:27, Michal Hocko wrote: > On Wed 25-07-18 16:20:41, David Hildenbrand wrote: >> On 25.07.2018 15:51, Michal Hocko wrote: >>> On Tue 24-07-18 16:13:09, David Hildenbrand wrote: >>> [...] So I see right now: - Pg_reserved + e.g. new page type (or some other unique iden

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-26 Thread Michal Hocko
On Thu 26-07-18 10:22:41, David Hildenbrand wrote: > On 24.07.2018 09:22, Michal Hocko wrote: > > On Mon 23-07-18 19:12:58, David Hildenbrand wrote: > >> On 23.07.2018 13:45, Vlastimil Babka wrote: > >>> On 07/20/2018 02:34 PM, David Hildenbrand wrote: > Dumping tools (like makedumpfile) right

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-26 Thread Michal Hocko
On Wed 25-07-18 16:20:41, David Hildenbrand wrote: > On 25.07.2018 15:51, Michal Hocko wrote: > > On Tue 24-07-18 16:13:09, David Hildenbrand wrote: > > [...] > >> So I see right now: > >> > >> - Pg_reserved + e.g. new page type (or some other unique identifier in > >> combination with Pg_reserve

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-26 Thread David Hildenbrand
On 24.07.2018 09:22, Michal Hocko wrote: > On Mon 23-07-18 19:12:58, David Hildenbrand wrote: >> On 23.07.2018 13:45, Vlastimil Babka wrote: >>> On 07/20/2018 02:34 PM, David Hildenbrand wrote: Dumping tools (like makedumpfile) right now don't exclude reserved pages. So reserved pages mig

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-25 Thread David Hildenbrand
On 25.07.2018 15:51, Michal Hocko wrote: > On Tue 24-07-18 16:13:09, David Hildenbrand wrote: > [...] >> So I see right now: >> >> - Pg_reserved + e.g. new page type (or some other unique identifier in >> combination with Pg_reserved) >> -> Avoid reads of pages we know are offline >> - extend is

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-25 Thread Michal Hocko
On Tue 24-07-18 16:13:09, David Hildenbrand wrote: [...] > So I see right now: > > - Pg_reserved + e.g. new page type (or some other unique identifier in > combination with Pg_reserved) > -> Avoid reads of pages we know are offline > - extend is_ram_page() > -> Fake zero memory for pages we kn

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread David Hildenbrand
On 24.07.2018 15:35, Michal Hocko wrote: > On Tue 24-07-18 15:27:51, David Hildenbrand wrote: >> On 24.07.2018 15:13, Michal Hocko wrote: >>> On Tue 24-07-18 14:17:12, David Hildenbrand wrote: On 24.07.2018 09:25, Michal Hocko wrote: > On Mon 23-07-18 19:20:43, David Hildenbrand wrote: >>>

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Michal Hocko
On Tue 24-07-18 15:27:51, David Hildenbrand wrote: > On 24.07.2018 15:13, Michal Hocko wrote: > > On Tue 24-07-18 14:17:12, David Hildenbrand wrote: > >> On 24.07.2018 09:25, Michal Hocko wrote: > >>> On Mon 23-07-18 19:20:43, David Hildenbrand wrote: > On 23.07.2018 14:30, Michal Hocko wrote:

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread David Hildenbrand
On 24.07.2018 15:13, Michal Hocko wrote: > On Tue 24-07-18 14:17:12, David Hildenbrand wrote: >> On 24.07.2018 09:25, Michal Hocko wrote: >>> On Mon 23-07-18 19:20:43, David Hildenbrand wrote: On 23.07.2018 14:30, Michal Hocko wrote: > On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: >

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Michal Hocko
On Tue 24-07-18 14:17:12, David Hildenbrand wrote: > On 24.07.2018 09:25, Michal Hocko wrote: > > On Mon 23-07-18 19:20:43, David Hildenbrand wrote: > >> On 23.07.2018 14:30, Michal Hocko wrote: > >>> On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: > On 07/20/2018 02:34 PM, David Hildenbrand

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Michal Hocko
On Tue 24-07-18 14:22:06, Vlastimil Babka wrote: > On 07/24/2018 01:19 PM, Michal Hocko wrote: > >> When creating a crashdump, I definitely need the pages containing memmap > >> included in the dump, so I can inspect the struct pages. But this is a > >> bit recursive issue, so I'll try making it cl

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread David Hildenbrand
On 24.07.2018 14:22, Vlastimil Babka wrote: > On 07/24/2018 01:19 PM, Michal Hocko wrote: >>> When creating a crashdump, I definitely need the pages containing memmap >>> included in the dump, so I can inspect the struct pages. But this is a >>> bit recursive issue, so I'll try making it clearer: >

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Vlastimil Babka
On 07/24/2018 01:19 PM, Michal Hocko wrote: >> When creating a crashdump, I definitely need the pages containing memmap >> included in the dump, so I can inspect the struct pages. But this is a >> bit recursive issue, so I'll try making it clearer: >> >> 1) there are kernel pages with data (e.g. sl

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread David Hildenbrand
On 24.07.2018 09:25, Michal Hocko wrote: > On Mon 23-07-18 19:20:43, David Hildenbrand wrote: >> On 23.07.2018 14:30, Michal Hocko wrote: >>> On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: On 07/20/2018 02:34 PM, David Hildenbrand wrote: > Dumping tools (like makedumpfile) right now don'

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Michal Hocko
On Tue 24-07-18 11:47:02, Vlastimil Babka wrote: > On 07/23/2018 02:30 PM, Michal Hocko wrote: > > On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: > >> On 07/20/2018 02:34 PM, David Hildenbrand wrote: > >>> Dumping tools (like makedumpfile) right now don't exclude reserved pages. > >>> So reserved

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Vlastimil Babka
On 07/24/2018 09:22 AM, Michal Hocko wrote: > On Mon 23-07-18 19:12:58, David Hildenbrand wrote: >> On 23.07.2018 13:45, Vlastimil Babka wrote: >>> On 07/20/2018 02:34 PM, David Hildenbrand wrote: Dumping tools (like makedumpfile) right now don't exclude reserved pages. So reserved pages

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Vlastimil Babka
On 07/23/2018 02:30 PM, Michal Hocko wrote: > On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: >> On 07/20/2018 02:34 PM, David Hildenbrand wrote: >>> Dumping tools (like makedumpfile) right now don't exclude reserved pages. >>> So reserved pages might be access by dump tools although nobody except

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread David Hildenbrand
On 24.07.2018 10:53, Michal Hocko wrote: > On Tue 24-07-18 10:46:20, David Hildenbrand wrote: >> On 24.07.2018 09:25, Michal Hocko wrote: >>> On Mon 23-07-18 19:20:43, David Hildenbrand wrote: On 23.07.2018 14:30, Michal Hocko wrote: > On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: >

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Michal Hocko
On Tue 24-07-18 10:46:20, David Hildenbrand wrote: > On 24.07.2018 09:25, Michal Hocko wrote: > > On Mon 23-07-18 19:20:43, David Hildenbrand wrote: > >> On 23.07.2018 14:30, Michal Hocko wrote: > >>> On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: > On 07/20/2018 02:34 PM, David Hildenbrand

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread David Hildenbrand
On 24.07.2018 09:25, Michal Hocko wrote: > On Mon 23-07-18 19:20:43, David Hildenbrand wrote: >> On 23.07.2018 14:30, Michal Hocko wrote: >>> On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: On 07/20/2018 02:34 PM, David Hildenbrand wrote: > Dumping tools (like makedumpfile) right now don'

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Michal Hocko
On Mon 23-07-18 19:20:43, David Hildenbrand wrote: > On 23.07.2018 14:30, Michal Hocko wrote: > > On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: > >> On 07/20/2018 02:34 PM, David Hildenbrand wrote: > >>> Dumping tools (like makedumpfile) right now don't exclude reserved pages. > >>> So reserved

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-24 Thread Michal Hocko
On Mon 23-07-18 19:12:58, David Hildenbrand wrote: > On 23.07.2018 13:45, Vlastimil Babka wrote: > > On 07/20/2018 02:34 PM, David Hildenbrand wrote: > >> Dumping tools (like makedumpfile) right now don't exclude reserved pages. > >> So reserved pages might be access by dump tools although nobody e

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-23 Thread David Hildenbrand
On 23.07.2018 14:30, Michal Hocko wrote: > On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: >> On 07/20/2018 02:34 PM, David Hildenbrand wrote: >>> Dumping tools (like makedumpfile) right now don't exclude reserved pages. >>> So reserved pages might be access by dump tools although nobody except >>

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-23 Thread David Hildenbrand
On 23.07.2018 13:45, Vlastimil Babka wrote: > On 07/20/2018 02:34 PM, David Hildenbrand wrote: >> Dumping tools (like makedumpfile) right now don't exclude reserved pages. >> So reserved pages might be access by dump tools although nobody except >> the owner should touch them. > > Are you sure abo

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-23 Thread Michal Hocko
On Mon 23-07-18 13:45:18, Vlastimil Babka wrote: > On 07/20/2018 02:34 PM, David Hildenbrand wrote: > > Dumping tools (like makedumpfile) right now don't exclude reserved pages. > > So reserved pages might be access by dump tools although nobody except > > the owner should touch them. > > Are you

Re: [PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-23 Thread Vlastimil Babka
On 07/20/2018 02:34 PM, David Hildenbrand wrote: > Dumping tools (like makedumpfile) right now don't exclude reserved pages. > So reserved pages might be access by dump tools although nobody except > the owner should touch them. Are you sure about that? Or maybe I understand wrong. Maybe it change

[PATCH v1 0/2] mm/kdump: exclude reserved pages in dumps

2018-07-20 Thread David Hildenbrand
Dumping tools (like makedumpfile) right now don't exclude reserved pages. So reserved pages might be access by dump tools although nobody except the owner should touch them. This is relevant in virtual environments where we soon might want to report certain reserved pages to the hypervisor and the