The patch titled
Subject: powerpc/powernv: hold device_hotplug_lock when calling memtrace_offline_pages()
has been added to the -mm tree. Its filename is
powerpc-powernv-hold-device_hotplug_lock-when-calling-memtrace_offline_pages.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/powerpc-powernv-hold-device_hotplug_lock-when-calling-memtrace_offline_pages.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/powerpc-powernv-hold-device_hotplug_lock-when-calling-memtrace_offline_pages.patch
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------------------------------------------------------
From: David Hildenbrand <david@xxxxxxxxxx>
Subject: powerpc/powernv: hold device_hotplug_lock when calling memtrace_offline_pages()
Let's perform all checking + offlining + removing under
device_hotplug_lock, so nobody can mess with these devices via sysfs
concurrently.
Link: http://lkml.kernel.org/r/20180925091457.28651-6-david@xxxxxxxxxx
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Pavel Tatashin <pavel.tatashin@xxxxxxxxxxxxx>
Reviewed-by: Rashmica Gupta <rashmica.g@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Rashmica Gupta <rashmica.g@xxxxxxxxx>
Cc: Balbir Singh <bsingharora@xxxxxxxxx>
Cc: Michael Neuling <mikey@xxxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: John Allen <jallen@xxxxxxxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Kate Stewart <kstewart@xxxxxxxxxxxxxxxxxxx>
Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
Cc: Len Brown <lenb@xxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Mathieu Malaterre <malat@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Nathan Fontenot <nfont@xxxxxxxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Philippe Ombredanne <pombredanne@xxxxxxxx>
Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: YASUAKI ISHIMATSU <yasu.isimatu@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/platforms/powernv/memtrace.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/arch/powerpc/platforms/powernv/memtrace.c~powerpc-powernv-hold-device_hotplug_lock-when-calling-memtrace_offline_pages
+++ a/arch/powerpc/platforms/powernv/memtrace.c
@@ -70,6 +70,7 @@ static int change_memblock_state(struct
return 0;
}
+/* called with device_hotplug_lock held */
static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages)
{
u64 end_pfn = start_pfn + nr_pages - 1;
@@ -111,6 +112,7 @@ static u64 memtrace_alloc_node(u32 nid,
end_pfn = round_down(end_pfn - nr_pages, nr_pages);
for (base_pfn = end_pfn; base_pfn > start_pfn; base_pfn -= nr_pages) {
+ lock_device_hotplug();
if (memtrace_offline_pages(nid, base_pfn, nr_pages) == true) {
/*
* Remove memory in memory block size chunks so that
@@ -118,7 +120,6 @@ static u64 memtrace_alloc_node(u32 nid,
* we never try to remove memory that spans two iomem
* resources.
*/
- lock_device_hotplug();
end_pfn = base_pfn + nr_pages;
for (pfn = base_pfn; pfn < end_pfn; pfn += bytes>> PAGE_SHIFT) {
__remove_memory(nid, pfn << PAGE_SHIFT, bytes);
@@ -126,6 +127,7 @@ static u64 memtrace_alloc_node(u32 nid,
unlock_device_hotplug();
return base_pfn << PAGE_SHIFT;
}
+ unlock_device_hotplug();
}
return 0;
_
Patches currently in -mm which might be from david@xxxxxxxxxx are
mm-memory_hotplug-make-remove_memory-take-the-device_hotplug_lock.patch
mm-memory_hotplug-make-add_memory-take-the-device_hotplug_lock.patch
mm-memory_hotplug-fix-online-offline_pages-called-wo-mem_hotplug_lock.patch
powerpc-powernv-hold-device_hotplug_lock-when-calling-device_online.patch
powerpc-powernv-hold-device_hotplug_lock-when-calling-memtrace_offline_pages.patch
memory-hotplugtxt-add-some-details-about-locking-internals.patch
