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Groups > linux.kernel > #1616958
| From | Michal Hocko <mhocko@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 0/6] mm: make movable onlining suck less |
| Date | 2017-04-05 16:00 +0200 |
| Message-ID | <tsTDA-3ln-19@gated-at.bofh.it> (permalink) |
| References | (5 earlier) <tszbR-78Z-35@gated-at.bofh.it> <tszOx-7qW-13@gated-at.bofh.it> <tsBx0-ao-23@gated-at.bofh.it> <tsCCK-RD-9@gated-at.bofh.it> <tsEuS-21A-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue 04-04-17 16:43:39, Reza Arbab wrote:
> On Tue, Apr 04, 2017 at 09:41:22PM +0200, Michal Hocko wrote:
> >On Tue 04-04-17 13:30:13, Reza Arbab wrote:
> >>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
> >
> >Is this something new or an old issue? I believe the state after the
> >online should be the same as before. So if you onlined the full node
> >then there shouldn't be any difference. Let me have a look...
>
> It's new. Without this patchset, I can repeatedly
> add_memory()->online_movable->offline->remove_memory() all of a node's
> memory.
OK, I know what is going on here.
shrink_pgdat_span: start_pfn=0x1ff00, end_pfn=0x20000, pgdat_start_pfn=0x0, pgdat_end_pfn=0x20000
[...]
find_biggest_section_pfn loop: pfn=0xff, sec_nr = 0x0
so the node starts at pfn 0 while we are trying to remove range starting
from pfn=255 (1MB). Rather than going with find_smallest_section_pfn we
go with the other branch and that underflows as already mentioned. I
seriously doubt that the node really starts at pfn 0. I am not sure
which arch you are testing on but I believe we reserve the lowest
address pfn range on all aches. The previous code presumably handled
that properly because the original node/zone has started at the lowest
possible address and the zone shifting then preserves that.
My code doesn't do that though. So I guess I have to sanitize. Does this
help? Please drop the "mm, memory_hotplug: get rid of zone/node
shrinking" patch.
---
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index acf2b5eb5ecb..2c5613d19eb6 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -750,6 +750,15 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
int ret;
struct memory_notify arg;
+ do {
+ if (pfn_valid(pfn))
+ break;
+ pfn++;
+ } while (--nr_pages > 0);
+
+ if (!nr_pages)
+ return -EINVAL;
+
nid = pfn_to_nid(pfn);
if (!allow_online_pfn_range(nid, pfn, nr_pages, online_type))
return -EINVAL;
--
Michal Hocko
SUSE Labs
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[PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
[PATCH 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
Re: [PATCH 1/6] mm: get rid of zone_is_initialized "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-03-31 05:50 +0200
Re: [PATCH 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-03-31 08:50 +0200
Re: [PATCH 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-03-31 08:50 +0200
[PATCH v1 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-03-31 09:50 +0200
Re: [PATCH v1 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-04-05 10:20 +0200
Re: [PATCH v1 1/6] mm: get rid of zone_is_initialized Michal Hocko <mhocko@kernel.org> - 2017-04-05 11:30 +0200
Re: [PATCH v1 1/6] mm: get rid of zone_is_initialized Igor Mammedov <imammedo@redhat.com> - 2017-04-05 11:50 +0200
[PATCH 2/6] mm, tile: drop arch_{add,remove}_memory Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
[PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-03-31 06:00 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-03-31 08:50 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-03-31 09:10 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-03-31 09:20 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-03-31 09:50 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-03 23:30 +0200
Re: [PATCH 3/6] mm: remove return value from init_currently_empty_zone Michal Hocko <mhocko@kernel.org> - 2017-04-04 09:40 +0200
[PATCH 6/6] mm, memory_hotplug: remove unused cruft after memory hotplug rework Michal Hocko <mhocko@kernel.org> - 2017-03-30 14:00 +0200
Re: [PATCH 6/6] mm, memory_hotplug: remove unused cruft after memory hotplug rework Michal Hocko <mhocko@kernel.org> - 2017-03-31 09:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Heiko Carstens <heiko.carstens@de.ibm.com> - 2017-03-31 21:20 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-03 09:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-03 14:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Igor Mammedov <imammedo@redhat.com> - 2017-04-03 14:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-03 22:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-03 22:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-03 22:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 09:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 09:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 10:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-04 18:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-04 18:10 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 18:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-04 20:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-04 21:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-04 23:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 08:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 11:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 17:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 17:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 19:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 20:20 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 21:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 23:10 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 13:10 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 18:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 18:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 23:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 11:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 16:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-05 17:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-05 08:40 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 15:10 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-06 17:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Reza Arbab <arbab@linux.vnet.ibm.com> - 2017-04-06 17:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 18:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Mel Gorman <mgorman@suse.de> - 2017-04-06 18:30 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Mel Gorman <mgorman@suse.de> - 2017-04-06 19:00 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 19:20 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Mel Gorman <mgorman@suse.de> - 2017-04-06 19:50 +0200
Re: [PATCH 0/6] mm: make movable onlining suck less Michal Hocko <mhocko@kernel.org> - 2017-04-06 17:50 +0200
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