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authorPavel Tatashin <pasha.tatashin@oracle.com>2018-04-06 02:22:56 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-06 07:36:25 +0300
commitfc44f7f9231a73821fc858f5bc48883a9e78f6de (patch)
tree52d633c375d235c3fd059d885981e821f0ee31f4 /drivers/base
parentb77eab7079d9e477489d2416cceda05d3c1cf21f (diff)
downloadlinux-fc44f7f9231a73821fc858f5bc48883a9e78f6de.tar.xz
mm/memory_hotplug: don't read nid from struct page during hotplug
During memory hotplugging the probe routine will leave struct pages uninitialized, the same as it is currently done during boot. Therefore, we do not want to access the inside of struct pages before __init_single_page() is called during onlining. Because during hotplug we know that pages in one memory block belong to the same numa node, we can skip the checking. We should keep checking for the boot case. [pasha.tatashin@oracle.com: s/register_new_memory()/hotplug_memory_register()] Link: http://lkml.kernel.org/r/20180228030308.1116-6-pasha.tatashin@oracle.com Link: http://lkml.kernel.org/r/20180215165920.8570-6-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Bharata B Rao <bharata@linux.vnet.ibm.com> Cc: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Steven Sistare <steven.sistare@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/memory.c4
-rw-r--r--drivers/base/node.c22
2 files changed, 17 insertions, 9 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index deb3f029b451..79fcd2bae96b 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -712,7 +712,7 @@ static int add_memory_block(int base_section_nr)
* need an interface for the VM to add new memory regions,
* but without onlining it.
*/
-int register_new_memory(int nid, struct mem_section *section)
+int hotplug_memory_register(int nid, struct mem_section *section)
{
int ret = 0;
struct memory_block *mem;
@@ -731,7 +731,7 @@ int register_new_memory(int nid, struct mem_section *section)
}
if (mem->section_count == sections_per_block)
- ret = register_mem_sect_under_node(mem, nid);
+ ret = register_mem_sect_under_node(mem, nid, false);
out:
mutex_unlock(&mem_sysfs_mutex);
return ret;
diff --git a/drivers/base/node.c b/drivers/base/node.c
index c5f81fc621ac..92b00a7e6a02 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -399,7 +399,8 @@ static int __ref get_nid_for_pfn(unsigned long pfn)
}
/* register memory section under specified node if it spans that node */
-int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
+int register_mem_sect_under_node(struct memory_block *mem_blk, int nid,
+ bool check_nid)
{
int ret;
unsigned long pfn, sect_start_pfn, sect_end_pfn;
@@ -425,11 +426,18 @@ int register_mem_sect_under_node(struct memory_block *mem_blk, int nid)
continue;
}
- page_nid = get_nid_for_pfn(pfn);
- if (page_nid < 0)
- continue;
- if (page_nid != nid)
- continue;
+ /*
+ * We need to check if page belongs to nid only for the boot
+ * case, during hotplug we know that all pages in the memory
+ * block belong to the same node.
+ */
+ if (check_nid) {
+ page_nid = get_nid_for_pfn(pfn);
+ if (page_nid < 0)
+ continue;
+ if (page_nid != nid)
+ continue;
+ }
ret = sysfs_create_link_nowarn(&node_devices[nid]->dev.kobj,
&mem_blk->dev.kobj,
kobject_name(&mem_blk->dev.kobj));
@@ -504,7 +512,7 @@ int link_mem_sections(int nid, unsigned long start_pfn, unsigned long nr_pages)
mem_blk = find_memory_block_hinted(mem_sect, mem_blk);
- ret = register_mem_sect_under_node(mem_blk, nid);
+ ret = register_mem_sect_under_node(mem_blk, nid, true);
if (!err)
err = ret;