From bfe63d3beabfac93521c8b7ccd40befd7a90148e Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Thu, 6 Jul 2017 15:37:42 -0700
Subject: [PATCH] mm: drop page_initialized check from get_nid_for_pfn
Commit 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 because this will become a problem with
later patches.
Thanks to Reza Arbab for testing which revealed this to be a problem
(http://lkml.kernel.org/r/20170403202337.GA12482@dhcp22.suse.cz)
Link: http://lkml.kernel.org/r/20170515085827.16474-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Tobias Regnery <tobias.regnery@gmail.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
drivers/base/node.c | 7 -------
1 file changed, 7 deletions(-)
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 0440d95c9b5be..db769d3148b74 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -368,21 +368,14 @@ 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;
-
if (!pfn_valid_within(pfn))
return -1;
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
if (system_state < SYSTEM_RUNNING)
return early_pfn_to_nid(pfn);
#endif
- page = pfn_to_page(pfn);
- if (!page_initialized(page))
- return -1;
return pfn_to_nid(pfn);
}
--
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