lkml.org 
[lkml]   [2020]   [Aug]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v6 00/12] HWPOISON: soft offline rework
On Tue, Aug 11, 2020 at 01:39:24PM -0400, Qian Cai wrote:
> On Tue, Aug 11, 2020 at 03:11:40AM +0000, HORIGUCHI NAOYA(堀口 直也) wrote:
> > I'm still not sure why the test succeeded by reverting these because
> > current mainline kernel provides similar mechanism to prevent reuse of
> > soft offlined page. So this success seems to me something suspicious.
> >
> > To investigate more, I want to have additional info about the page states
> > of the relevant pages after soft offlining. Could you collect it by the
> > following steps?
> >
> > - modify random.c not to run hotplug_memory() in migrate_huge_hotplug_memory(),
> > - compile it and run "./random 1" once,
> > - to collect page state with hwpoisoned pages, run "./page-types -Nlr -b hwpoison",
> > where page-types is available under tools/vm in kernel source tree.
> > - choose a few pfns of soft offlined pages from kernel message
> > "Soft offlining pfn ...", and run "./page-types -Nlr -a <pfn>".
>
> # ./page-types -Nlr -b hwpoison
> offset len flags
> 99a000 1 __________B________X_______________________
> 99c000 1 __________B________X_______________________
> 99e000 1 __________B________X_______________________
> 9a0000 1 __________B________X_______________________
> ba6000 1 __________B________X_______________________
> baa000 1 __________B________X_______________________

Thank you. It only shows 6 lines of records, which is unexpected to me
because random.c iterates soft offline 2 hugepages with madvise() 1000 times.
Somehow (maybe in arch specific way?) other hwpoisoned pages might be cleared?
If they really are, the success of this test is a fake, and this patchset
can be considered as a fix.

>
> Every single one of pfns was like this,
>
> # ./page-types -Nlr -a 0x99a000
> offset len flags
> 99a000 1 __________B________X_______________________
>
> # ./page-types -Nlr -a 0x99e000
> offset len flags
> 99e000 1 __________B________X_______________________
>
> # ./page-types -Nlr -a 0x99c000
> offset len flags
> 99c000 1 __________B________X_______________________

\
 
 \ /
  Last update: 2020-08-11 21:33    [W:0.079 / U:0.948 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site