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Groups > linux.kernel > #1615776
| From | Michal Hocko <mhocko@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 0/6] mm: make movable onlining suck less |
| Date | 2017-04-04 10:30 +0200 |
| Message-ID | <tss0F-2lg-3@gated-at.bofh.it> (permalink) |
| References | (2 earlier) <tsgiT-2PU-27@gated-at.bofh.it> <tsgLT-3gI-3@gated-at.bofh.it> <tsh5g-3nO-21@gated-at.bofh.it> <tsr4B-1Jj-1@gated-at.bofh.it> <tsrei-1N1-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Tue 04-04-17 09:34:12, Michal Hocko wrote:
> On Tue 04-04-17 09:23:29, Michal Hocko wrote:
> > [Let's add Gary who as introduced this code c04fc586c1a48]
>
> OK, so Gary's email doesn't exist anymore. Does anybody can comment on
> this? I suspect this code is just-in-case... Mel?
>
> > On Mon 03-04-17 15:42:13, Reza Arbab wrote:
> [...]
> > > Almost there. I'm seeing the memory in the correct node now, but the
> > > /sys/devices/system/node/nodeX/memoryY links are not being created.
> > >
> > > I think it's tripping up here, in register_mem_sect_under_node():
> > >
> > > page_nid = get_nid_for_pfn(pfn);
> > > if (page_nid < 0)
> > > continue;
> >
> > Huh, this code is confusing. How can we have a memblock spanning more
> > nodes? If not then the loop over all sections in the memblock seem
> > pointless as well. Also why do we require page_initialized() in
> > get_nid_for_pfn? The changelog doesn't explain that and there are no
> > comments that would help either.
OK, so I've been thinkin about that and I believe that page_initialized
check in get_nid_for_pfn is just bogus. There is nothing to rely on the
page::lru to be already initialized. So I will go with the following as
a separate preparatory patch.
I believe the whole code should be revisited and I have put that on my
ever growing todo list because I suspect that it is more complex than
necessary. I suspect that memblock do not span more nodes and all this
is just-in-case code (e.g. the onlining code assumes a single zone aka
node. But let's do that later.
---
From fd2e3b6eca1cf7766527203d23db6aca5957a3f1 Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Tue, 4 Apr 2017 10:05:06 +0200
Subject: [PATCH] mm: drop page_initialized check from get_nid_for_pfn
c04fc586c1a4 ("mm: show node to memory section relationship with
symlinks in sysfs") has added means to export memblock<->node
association into the sysfs. It has also introduced get_nid_for_pfn
which is a rather confusing counterpart of pfn_to_nid which checks also
whether the pfn page is already initialized (page_initialized). This
is done by checking page::lru != NULL which doesn't make any sense at
all. Nothing in this path really relies on the lru list being used or
initialized. Just remove it
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
drivers/base/node.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 5548f9686016..ee080a35e869 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -368,8 +368,6 @@ int unregister_cpu_under_node(unsigned int cpu, unsigned int nid)
}
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
-#define page_initialized(page) (page->lru.next)
-
static int __ref get_nid_for_pfn(unsigned long pfn)
{
struct page *page;
@@ -380,9 +378,6 @@ static int __ref get_nid_for_pfn(unsigned long pfn)
if (system_state == SYSTEM_BOOTING)
return early_pfn_to_nid(pfn);
#endif
- page = pfn_to_page(pfn);
- if (!page_initialized(page))
- return -1;
return pfn_to_nid(pfn);
}
--
2.11.0
--
Michal Hocko
SUSE Labs
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[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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