Re: uninitialized pmem struct pages

2021-01-05 Thread David Hildenbrand
On 05.01.21 10:56, Dan Williams wrote: > On Tue, Jan 5, 2021 at 1:37 AM David Hildenbrand wrote: >> Yeah, obviously the first one. Being able to add+use PMEM is more important than using each and every last MB of main memory. I wonder if we can just stop adding any system RAM

Re: uninitialized pmem struct pages

2021-01-05 Thread David Hildenbrand
On 05.01.21 08:44, Michal Hocko wrote: > On Mon 04-01-21 17:30:48, David Hildenbrand wrote: Let's assume this is indeed a reserved pfn in the altmap. What's the actual address of the memmap? >>> >>> Not sure what exactly you are asking for but crash says >>> crash> kmem -p 606 >>>

Re: uninitialized pmem struct pages

2021-01-05 Thread Dan Williams
On Tue, Jan 5, 2021 at 1:37 AM David Hildenbrand wrote: > > >> Yeah, obviously the first one. Being able to add+use PMEM is more > >> important than using each and every last MB of main memory. > >> > >> I wonder if we can just stop adding any system RAM like > >> > >> [ Memory Section] >

Re: uninitialized pmem struct pages

2021-01-05 Thread David Hildenbrand
>> Yeah, obviously the first one. Being able to add+use PMEM is more >> important than using each and every last MB of main memory. >> >> I wonder if we can just stop adding any system RAM like >> >> [ Memory Section] >> [ RAM ] [ Hole ] >> >> When there could be the possibility

Re: uninitialized pmem struct pages

2021-01-05 Thread Dan Williams
you have recommended 53cdc1cb29e8 > >>> ("drivers/base/memory.c: indicate all memory blocks as removable") to be > >>> backported to stable trees and that has led to a more general discussion > >>> about the current state of pfn walkers wr

Re: uninitialized pmem struct pages

2021-01-05 Thread David Hildenbrand
On 05.01.21 10:25, Michal Hocko wrote: > On Tue 05-01-21 10:13:49, David Hildenbrand wrote: >> On 05.01.21 10:05, Michal Hocko wrote: >>> On Tue 05-01-21 00:57:43, Dan Williams wrote: On Tue, Jan 5, 2021 at 12:42 AM Michal Hocko wrote: > > On Tue 05-01-21 00:27:34, Dan Williams

Re: uninitialized pmem struct pages

2021-01-05 Thread David Hildenbrand
mory blocks as removable") to be >>> backported to stable trees and that has led to a more general discussion >>> about the current state of pfn walkers wrt. uninitialized pmem struct >>> pages. We haven't concluded any specific solution for that except for a >

Re: uninitialized pmem struct pages

2021-01-05 Thread Michal Hocko
On Tue 05-01-21 10:13:49, David Hildenbrand wrote: > On 05.01.21 10:05, Michal Hocko wrote: > > On Tue 05-01-21 00:57:43, Dan Williams wrote: > >> On Tue, Jan 5, 2021 at 12:42 AM Michal Hocko wrote: > >>> > >>> On Tue 05-01-21 00:27:34, Dan Williams wrote: > On Tue, Jan 5, 2021 at 12:17 AM

Re: uninitialized pmem struct pages

2021-01-05 Thread David Hildenbrand
On 05.01.21 08:50, Michal Hocko wrote: > On Mon 04-01-21 21:17:43, Dan Williams wrote: >> On Mon, Jan 4, 2021 at 2:45 AM David Hildenbrand wrote: > [...] >>> I believe Dan mentioned somewhere that he wants to see a real instance >>> of this producing a BUG before actually moving forward with a

Re: uninitialized pmem struct pages

2021-01-05 Thread David Hildenbrand
On 05.01.21 10:05, Michal Hocko wrote: > On Tue 05-01-21 00:57:43, Dan Williams wrote: >> On Tue, Jan 5, 2021 at 12:42 AM Michal Hocko wrote: >>> >>> On Tue 05-01-21 00:27:34, Dan Williams wrote: On Tue, Jan 5, 2021 at 12:17 AM Michal Hocko wrote: > > On Tue 05-01-21 09:01:00,

Re: uninitialized pmem struct pages

2021-01-05 Thread Michal Hocko
On Tue 05-01-21 00:57:43, Dan Williams wrote: > On Tue, Jan 5, 2021 at 12:42 AM Michal Hocko wrote: > > > > On Tue 05-01-21 00:27:34, Dan Williams wrote: > > > On Tue, Jan 5, 2021 at 12:17 AM Michal Hocko wrote: > > > > > > > > On Tue 05-01-21 09:01:00, Michal Hocko wrote: > > > > > On Mon

Re: uninitialized pmem struct pages

2021-01-05 Thread Dan Williams
On Tue, Jan 5, 2021 at 12:42 AM Michal Hocko wrote: > > On Tue 05-01-21 00:27:34, Dan Williams wrote: > > On Tue, Jan 5, 2021 at 12:17 AM Michal Hocko wrote: > > > > > > On Tue 05-01-21 09:01:00, Michal Hocko wrote: > > > > On Mon 04-01-21 16:44:52, David Hildenbrand wrote: > > > > > On 04.01.21

Re: uninitialized pmem struct pages

2021-01-05 Thread Michal Hocko
On Tue 05-01-21 00:27:34, Dan Williams wrote: > On Tue, Jan 5, 2021 at 12:17 AM Michal Hocko wrote: > > > > On Tue 05-01-21 09:01:00, Michal Hocko wrote: > > > On Mon 04-01-21 16:44:52, David Hildenbrand wrote: > > > > On 04.01.21 16:43, David Hildenbrand wrote: > > > > > On 04.01.21 16:33,

Re: uninitialized pmem struct pages

2021-01-05 Thread Dan Williams
On Tue, Jan 5, 2021 at 12:17 AM Michal Hocko wrote: > > On Tue 05-01-21 09:01:00, Michal Hocko wrote: > > On Mon 04-01-21 16:44:52, David Hildenbrand wrote: > > > On 04.01.21 16:43, David Hildenbrand wrote: > > > > On 04.01.21 16:33, Michal Hocko wrote: > > > >> On Mon 04-01-21 16:15:23, David

Re: uninitialized pmem struct pages

2021-01-05 Thread Michal Hocko
On Tue 05-01-21 09:01:00, Michal Hocko wrote: > On Mon 04-01-21 16:44:52, David Hildenbrand wrote: > > On 04.01.21 16:43, David Hildenbrand wrote: > > > On 04.01.21 16:33, Michal Hocko wrote: > > >> On Mon 04-01-21 16:15:23, David Hildenbrand wrote: > > >>> On 04.01.21 16:10, Michal Hocko wrote: >

Re: uninitialized pmem struct pages

2021-01-05 Thread Michal Hocko
On Mon 04-01-21 16:44:52, David Hildenbrand wrote: > On 04.01.21 16:43, David Hildenbrand wrote: > > On 04.01.21 16:33, Michal Hocko wrote: > >> On Mon 04-01-21 16:15:23, David Hildenbrand wrote: > >>> On 04.01.21 16:10, Michal Hocko wrote: > >> [...] > >>> Do the physical addresses you see fall

Re: uninitialized pmem struct pages

2021-01-04 Thread Michal Hocko
On Mon 04-01-21 21:17:43, Dan Williams wrote: > On Mon, Jan 4, 2021 at 2:45 AM David Hildenbrand wrote: [...] > > I believe Dan mentioned somewhere that he wants to see a real instance > > of this producing a BUG before actually moving forward with a fix. I > > might be wrong. > > I think I'm

Re: uninitialized pmem struct pages

2021-01-04 Thread Michal Hocko
On Mon 04-01-21 17:30:48, David Hildenbrand wrote: > >> Let's assume this is indeed a reserved pfn in the altmap. What's the > >> actual address of the memmap? > > > > Not sure what exactly you are asking for but crash says > > crash> kmem -p 606 > > PAGE PHYSICAL MAPPING

Re: uninitialized pmem struct pages

2021-01-04 Thread Michal Hocko
On Mon 04-01-21 21:33:06, Dan Williams wrote: > On Mon, Jan 4, 2021 at 7:59 AM Michal Hocko wrote: [...] > > Not sure what exactly you are asking for but crash says > > crash> kmem -p 606 > > PAGE PHYSICAL MAPPING INDEX CNT FLAGS > > f8c600181800 606

Re: uninitialized pmem struct pages

2021-01-04 Thread Dan Williams
On Mon, Jan 4, 2021 at 7:59 AM Michal Hocko wrote: > > On Mon 04-01-21 16:43:49, David Hildenbrand wrote: > > On 04.01.21 16:33, Michal Hocko wrote: > > > On Mon 04-01-21 16:15:23, David Hildenbrand wrote: > > >> On 04.01.21 16:10, Michal Hocko wrote: > > > [...] > > >> Do the physical addresses

Re: uninitialized pmem struct pages

2021-01-04 Thread Dan Williams
stable trees and that has led to a more general discussion > > about the current state of pfn walkers wrt. uninitialized pmem struct > > pages. We haven't concluded any specific solution for that except for a > > general sentiment that pfn_to_online_page should be able to catch t

Re: uninitialized pmem struct pages

2021-01-04 Thread David Hildenbrand
>> Let's assume this is indeed a reserved pfn in the altmap. What's the >> actual address of the memmap? > > Not sure what exactly you are asking for but crash says > crash> kmem -p 606 > PAGE PHYSICAL MAPPING INDEX CNT FLAGS > f8c600181800 606

Re: uninitialized pmem struct pages

2021-01-04 Thread Michal Hocko
On Mon 04-01-21 16:43:49, David Hildenbrand wrote: > On 04.01.21 16:33, Michal Hocko wrote: > > On Mon 04-01-21 16:15:23, David Hildenbrand wrote: > >> On 04.01.21 16:10, Michal Hocko wrote: > > [...] > >> Do the physical addresses you see fall into the same section as boot > >> memory? Or what's

Re: uninitialized pmem struct pages

2021-01-04 Thread David Hildenbrand
On 04.01.21 16:43, David Hildenbrand wrote: > On 04.01.21 16:33, Michal Hocko wrote: >> On Mon 04-01-21 16:15:23, David Hildenbrand wrote: >>> On 04.01.21 16:10, Michal Hocko wrote: >> [...] >>> Do the physical addresses you see fall into the same section as boot >>> memory? Or what's around these

Re: uninitialized pmem struct pages

2021-01-04 Thread David Hildenbrand
On 04.01.21 16:33, Michal Hocko wrote: > On Mon 04-01-21 16:15:23, David Hildenbrand wrote: >> On 04.01.21 16:10, Michal Hocko wrote: > [...] >> Do the physical addresses you see fall into the same section as boot >> memory? Or what's around these addresses? > > Yes I am getting a garbage for the

Re: uninitialized pmem struct pages

2021-01-04 Thread Michal Hocko
On Mon 04-01-21 16:15:23, David Hildenbrand wrote: > On 04.01.21 16:10, Michal Hocko wrote: [...] > Do the physical addresses you see fall into the same section as boot > memory? Or what's around these addresses? Yes I am getting a garbage for the first struct page belonging to the pmem section

Re: uninitialized pmem struct pages

2021-01-04 Thread David Hildenbrand
On 04.01.21 16:10, Michal Hocko wrote: > On Mon 04-01-21 15:51:35, David Hildenbrand wrote: >> On 04.01.21 15:26, Michal Hocko wrote: >>> On Mon 04-01-21 11:45:39, David Hildenbrand wrote: > [] One instance where this is still an issue is mm/memory-failure.c:memory_failure() and

Re: uninitialized pmem struct pages

2021-01-04 Thread Michal Hocko
On Mon 04-01-21 15:51:35, David Hildenbrand wrote: > On 04.01.21 15:26, Michal Hocko wrote: > > On Mon 04-01-21 11:45:39, David Hildenbrand wrote: [] > >> One instance where this is still an issue is > >> mm/memory-failure.c:memory_failure() and > >> mm/memory-failure.c:soft_offline_page(). I

Re: uninitialized pmem struct pages

2021-01-04 Thread David Hildenbrand
locks as removable") to be >>> backported to stable trees and that has led to a more general discussion >>> about the current state of pfn walkers wrt. uninitialized pmem struct >>> pages. We haven't concluded any specific solution for that except for a >>> general

Re: uninitialized pmem struct pages

2021-01-04 Thread Michal Hocko
es and that has led to a more general discussion > > about the current state of pfn walkers wrt. uninitialized pmem struct > > pages. We haven't concluded any specific solution for that except for a > > general sentiment that pfn_to_online_page should be able to catch those.

Re: uninitialized pmem struct pages

2021-01-04 Thread David Hildenbrand
state of pfn walkers wrt. uninitialized pmem struct > pages. We haven't concluded any specific solution for that except for a > general sentiment that pfn_to_online_page should be able to catch those. > I might have missed any follow ups on that but I do not think we have > landed on any ac

uninitialized pmem struct pages

2021-01-04 Thread Michal Hocko
Hi, back in March [1] you have recommended 53cdc1cb29e8 ("drivers/base/memory.c: indicate all memory blocks as removable") to be backported to stable trees and that has led to a more general discussion about the current state of pfn walkers wrt. uninitialized pmem struct pages.