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mm/memmap_init: update variable name in memmap_init_zone

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Patch series "mm/memory_hotplug: Shrink zones before removing memory", v6.

This series fixes the access of uninitialized memmaps when shrinking
zones/nodes and when removing memory.  Also, it contains all fixes for
crashes that can be triggered when removing certain namespace using
memunmap_pages() - ZONE_DEVICE, reported by Aneesh.

We stop trying to shrink ZONE_DEVICE, as it's buggy, fixing it would be
more involved (we don't have SECTION_IS_ONLINE as an indicator), and
shrinking is only of limited use (set_zone_contiguous() cannot detect the
ZONE_DEVICE as contiguous).

We continue shrinking !ZONE_DEVICE zones, however, I reduced the amount of
code to a minimum.  Shrinking is especially necessary to keep
zone->contiguous set where possible, especially, on memory unplug of DIMMs
at zone boundaries.

--------------------------------------------------------------------------

Zones are now properly shrunk when offlining memory blocks or when
onlining failed.  This allows to properly shrink zones on memory unplug
even if the separate memory blocks of a DIMM were onlined to different
zones or re-onlined to a different zone after offlining.

Example:

:/# cat /proc/zoneinfo
Node 1, zone  Movable
        spanned  0
        present  0
        managed  0
:/# echo "online_movable" > /sys/devices/system/memory/memory41/state
:/# echo "online_movable" > /sys/devices/system/memory/memory43/state
:/# cat /proc/zoneinfo
Node 1, zone  Movable
        spanned  98304
        present  65536
        managed  65536
:/# echo 0 > /sys/devices/system/memory/memory43/online
:/# cat /proc/zoneinfo
Node 1, zone  Movable
        spanned  32768
        present  32768
        managed  32768
:/# echo 0 > /sys/devices/system/memory/memory41/online
:/# cat /proc/zoneinfo
Node 1, zone  Movable
        spanned  0
        present  0
        managed  0

This patch (of 6):

The third argument is actually number of pages.  Change the variable name
from size to nr_pages to indicate this better.

No functional change in this patch.

Link: http://lkml.kernel.org/r/20191006085646.5768-3-david@redhat.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Aneesh Kumar K.V 2020-02-03 17:34:06 -08:00 committed by Linus Torvalds
parent 4c6058814e
commit 1f8d75c1b7
1 changed files with 4 additions and 4 deletions
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8
mm/page_alloc.c
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@ -5946,10 +5946,10 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
#ifdef CONFIG_ZONE_DEVICE
void __ref memmap_init_zone_device(struct zone *zone,
unsigned long start_pfn,
unsigned long size,
unsigned long nr_pages,
struct dev_pagemap *pgmap)
{
unsigned long pfn, end_pfn = start_pfn + size;
unsigned long pfn, end_pfn = start_pfn + nr_pages;
struct pglist_data *pgdat = zone->zone_pgdat;
struct vmem_altmap *altmap = pgmap_altmap(pgmap);
unsigned long zone_idx = zone_idx(zone);
@ -5966,7 +5966,7 @@ void __ref memmap_init_zone_device(struct zone *zone,
*/
if (altmap) {
start_pfn = altmap->base_pfn + vmem_altmap_offset(altmap);
size = end_pfn - start_pfn;
nr_pages = end_pfn - start_pfn;
}
for (pfn = start_pfn; pfn < end_pfn; pfn++) {
@ -6013,7 +6013,7 @@ void __ref memmap_init_zone_device(struct zone *zone,
}
pr_info("%s initialised %lu pages in %ums\n", __func__,
size, jiffies_to_msecs(jiffies - start));
nr_pages, jiffies_to_msecs(jiffies - start));
}
#endif