The patch titled
Subject: mm, memory_hotplug: get rid of is_zone_device_section
has been added to the -mm tree. Its filename is
mm-memory_hotplug-get-rid-of-is_zone_device_section.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-memory_hotplug-get-rid-of-is_zone_device_section.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-memory_hotplug-get-rid-of-is_zone_device_section.patch
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------------------------------------------------------
From: Michal Hocko <mhocko@xxxxxxxx>
Subject: mm, memory_hotplug: get rid of is_zone_device_section
Device memory hotplug hooks into regular memory hotplug only half way. It
needs memory sections to track struct pages but there is no need/desire to
associate those sections with memory blocks and export them to the
userspace via sysfs because they cannot be onlined anyway.
This is currently expressed by for_device argument to arch_add_memory
which then makes sure to associate the given memory range with
ZONE_DEVICE. register_new_memory then relies on is_zone_device_section to
distinguish special memory hotplug from the regular one. While this works
now, later patches in this series want to move __add_zone outside of
arch_add_memory path so we have to come up with something else.
Add want_memblock down the __add_pages path and use it to control whether
the section->memblock association should be done. arch_add_memory then
just trivially want memblock for everything but for_device hotplug.
remove_memory_section doesn't need is_zone_device_section either. We can
simply skip all the memblock specific cleanup if there is no memblock for
the given section.
This shouldn't introduce any functional change.
Link: http://lkml.kernel.org/r/20170515085827.16474-5-mhocko@xxxxxxxxxx
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Tested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Balbir Singh <bsingharora@xxxxxxxxx>
Cc: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Igor Mammedov <imammedo@xxxxxxxxxx>
Cc: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: Joonsoo Kim <js1304@xxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Reza Arbab <arbab@xxxxxxxxxxxxxxxxxx>
Cc: Tobias Regnery <tobias.regnery@xxxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxxx>
Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Cc: Xishi Qiu <qiuxishi@xxxxxxxxxx>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/ia64/mm/init.c | 2 +-
arch/powerpc/mm/mem.c | 2 +-
arch/s390/mm/init.c | 2 +-
arch/sh/mm/init.c | 2 +-
arch/x86/mm/init_32.c | 2 +-
arch/x86/mm/init_64.c | 2 +-
drivers/base/memory.c | 23 +++++++++--------------
include/linux/memory_hotplug.h | 2 +-
mm/memory_hotplug.c | 9 ++++++---
9 files changed, 22 insertions(+), 24 deletions(-)
diff -puN arch/ia64/mm/init.c~mm-memory_hotplug-get-rid-of-is_zone_device_section arch/ia64/mm/init.c
--- a/arch/ia64/mm/init.c~mm-memory_hotplug-get-rid-of-is_zone_device_section
+++ a/arch/ia64/mm/init.c
@@ -658,7 +658,7 @@ int arch_add_memory(int nid, u64 start,
zone = pgdat->node_zones +
zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
- ret = __add_pages(nid, zone, start_pfn, nr_pages);
+ ret = __add_pages(nid, zone, start_pfn, nr_pages, !for_device);
if (ret)
printk("%s: Problem encountered in __add_pages() as ret=%d\n",
diff -puN arch/powerpc/mm/mem.c~mm-memory_hotplug-get-rid-of-is_zone_device_section arch/powerpc/mm/mem.c
--- a/arch/powerpc/mm/mem.c~mm-memory_hotplug-get-rid-of-is_zone_device_section
+++ a/arch/powerpc/mm/mem.c
@@ -151,7 +151,7 @@ int arch_add_memory(int nid, u64 start,
zone = pgdata->node_zones +
zone_for_memory(nid, start, size, 0, for_device);
- return __add_pages(nid, zone, start_pfn, nr_pages);
+ return __add_pages(nid, zone, start_pfn, nr_pages, !for_device);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
diff -puN arch/s390/mm/init.c~mm-memory_hotplug-get-rid-of-is_zone_device_section arch/s390/mm/init.c
--- a/arch/s390/mm/init.c~mm-memory_hotplug-get-rid-of-is_zone_device_section
+++ a/arch/s390/mm/init.c
@@ -191,7 +191,7 @@ int arch_add_memory(int nid, u64 start,
continue;
nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
zone_end_pfn - start_pfn : size_pages;
- rc = __add_pages(nid, zone, start_pfn, nr_pages);
+ rc = __add_pages(nid, zone, start_pfn, nr_pages, !for_device);
if (rc)
break;
start_pfn += nr_pages;
diff -puN arch/sh/mm/init.c~mm-memory_hotplug-get-rid-of-is_zone_device_section arch/sh/mm/init.c
--- a/arch/sh/mm/init.c~mm-memory_hotplug-get-rid-of-is_zone_device_section
+++ a/arch/sh/mm/init.c
@@ -498,7 +498,7 @@ int arch_add_memory(int nid, u64 start,
ret = __add_pages(nid, pgdat->node_zones +
zone_for_memory(nid, start, size, ZONE_NORMAL,
for_device),
- start_pfn, nr_pages);
+ start_pfn, nr_pages, !for_device);
if (unlikely(ret))
printk("%s: Failed, __add_pages() == %d\n", __func__, ret);
diff -puN arch/x86/mm/init_32.c~mm-memory_hotplug-get-rid-of-is_zone_device_section arch/x86/mm/init_32.c
--- a/arch/x86/mm/init_32.c~mm-memory_hotplug-get-rid-of-is_zone_device_section
+++ a/arch/x86/mm/init_32.c
@@ -831,7 +831,7 @@ int arch_add_memory(int nid, u64 start,
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
- return __add_pages(nid, zone, start_pfn, nr_pages);
+ return __add_pages(nid, zone, start_pfn, nr_pages, !for_device);
}
#ifdef CONFIG_MEMORY_HOTREMOVE
diff -puN arch/x86/mm/init_64.c~mm-memory_hotplug-get-rid-of-is_zone_device_section arch/x86/mm/init_64.c
--- a/arch/x86/mm/init_64.c~mm-memory_hotplug-get-rid-of-is_zone_device_section
+++ a/arch/x86/mm/init_64.c
@@ -697,7 +697,7 @@ int arch_add_memory(int nid, u64 start,
init_memory_mapping(start, start + size);
- ret = __add_pages(nid, zone, start_pfn, nr_pages);
+ ret = __add_pages(nid, zone, start_pfn, nr_pages, !for_device);
WARN_ON_ONCE(ret);
/* update max_pfn, max_low_pfn and high_memory */
diff -puN drivers/base/memory.c~mm-memory_hotplug-get-rid-of-is_zone_device_section drivers/base/memory.c
--- a/drivers/base/memory.c~mm-memory_hotplug-get-rid-of-is_zone_device_section
+++ a/drivers/base/memory.c
@@ -685,14 +685,6 @@ static int add_memory_block(int base_sec
return 0;
}
-static bool is_zone_device_section(struct mem_section *ms)
-{
- struct page *page;
-
- page = sparse_decode_mem_map(ms->section_mem_map, __section_nr(ms));
- return is_zone_device_page(page);
-}
-
/*
* need an interface for the VM to add new memory regions,
* but without onlining it.
@@ -702,9 +694,6 @@ int register_new_memory(int nid, struct
int ret = 0;
struct memory_block *mem;
- if (is_zone_device_section(section))
- return 0;
-
mutex_lock(&mem_sysfs_mutex);
mem = find_memory_block(section);
@@ -741,11 +730,16 @@ static int remove_memory_section(unsigne
{
struct memory_block *mem;
- if (is_zone_device_section(section))
- return 0;
-
mutex_lock(&mem_sysfs_mutex);
+
+ /*
+ * Some users of the memory hotplug do not want/need memblock to
+ * track all sections. Skip over those.
+ */
mem = find_memory_block(section);
+ if (!mem)
+ goto out_unlock;
+
unregister_mem_sect_under_nodes(mem, __section_nr(section));
mem->section_count--;
@@ -754,6 +748,7 @@ static int remove_memory_section(unsigne
else
put_device(&mem->dev);
+out_unlock:
mutex_unlock(&mem_sysfs_mutex);
return 0;
}
diff -puN include/linux/memory_hotplug.h~mm-memory_hotplug-get-rid-of-is_zone_device_section include/linux/memory_hotplug.h
--- a/include/linux/memory_hotplug.h~mm-memory_hotplug-get-rid-of-is_zone_device_section
+++ a/include/linux/memory_hotplug.h
@@ -111,7 +111,7 @@ extern int __remove_pages(struct zone *z
/* reasonably generic interface to expand the physical pages in a zone */
extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
- unsigned long nr_pages);
+ unsigned long nr_pages, bool want_memblock);
#ifdef CONFIG_NUMA
extern int memory_add_physaddr_to_nid(u64 start);
diff -puN mm/memory_hotplug.c~mm-memory_hotplug-get-rid-of-is_zone_device_section mm/memory_hotplug.c
--- a/mm/memory_hotplug.c~mm-memory_hotplug-get-rid-of-is_zone_device_section
+++ a/mm/memory_hotplug.c
@@ -494,7 +494,7 @@ static int __meminit __add_zone(struct z
}
static int __meminit __add_section(int nid, struct zone *zone,
- unsigned long phys_start_pfn)
+ unsigned long phys_start_pfn, bool want_memblock)
{
int ret;
@@ -511,6 +511,9 @@ static int __meminit __add_section(int n
if (ret < 0)
return ret;
+ if (!want_memblock)
+ return 0;
+
return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
}
@@ -521,7 +524,7 @@ static int __meminit __add_section(int n
* add the new pages.
*/
int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,
- unsigned long nr_pages)
+ unsigned long nr_pages, bool want_memblock)
{
unsigned long i;
int err = 0;
@@ -549,7 +552,7 @@ int __ref __add_pages(int nid, struct zo
}
for (i = start_sec; i <= end_sec; i++) {
- err = __add_section(nid, zone, section_nr_to_pfn(i));
+ err = __add_section(nid, zone, section_nr_to_pfn(i), want_memblock);
/*
* EEXIST is finally dealt with by ioresource collision
_
Patches currently in -mm which might be from mhocko@xxxxxxxx are
mm-remove-return-value-from-init_currently_empty_zone.patch
mm-memory_hotplug-use-node-instead-of-zone-in-can_online_high_movable.patch
mm-drop-page_initialized-check-from-get_nid_for_pfn.patch
mm-memory_hotplug-get-rid-of-is_zone_device_section.patch
mm-memory_hotplug-split-up-register_one_node.patch
mm-memory_hotplug-consider-offline-memblocks-removable.patch
mm-consider-zone-which-is-not-fully-populated-to-have-holes.patch
mm-compaction-skip-over-holes-in-__reset_isolation_suitable.patch
mm-__first_valid_page-skip-over-offline-pages.patch
mm-vmstat-skip-reporting-offline-pages-in-pagetypeinfo.patch
mm-memory_hotplug-do-not-associate-hotadded-memory-to-zones-until-online.patch
mm-memory_hotplug-replace-for_device-by-want_memblock-in-arch_add_memory.patch
mm-memory_hotplug-fix-the-section-mismatch-warning.patch
mm-memory_hotplug-remove-unused-cruft-after-memory-hotplug-rework.patch
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