Messages in this thread Patch in this message | | | From | David Hildenbrand <> | Subject | [PATCH v3 5/6] powerpc/powernv: hold device_hotplug_lock when calling memtrace_offline_pages() | Date | Thu, 27 Sep 2018 11:25:53 +0200 |
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Let's perform all checking + offlining + removing under device_hotplug_lock, so nobody can mess with these devices via sysfs concurrently.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rashmica Gupta <rashmica.g@gmail.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Michael Neuling <mikey@neuling.org> Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by: Rashmica Gupta <rashmica.g@gmail.com> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> --- arch/powerpc/platforms/powernv/memtrace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index fdd48f1a39f7..84d038ed3882 100644 --- a/arch/powerpc/platforms/powernv/memtrace.c +++ b/arch/powerpc/platforms/powernv/memtrace.c @@ -70,6 +70,7 @@ static int change_memblock_state(struct memory_block *mem, void *arg) 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; @@ -110,6 +111,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) /* Trace memory needs to be aligned to the size */ end_pfn = round_down(end_pfn - nr_pages, nr_pages); + lock_device_hotplug(); for (base_pfn = end_pfn; base_pfn > start_pfn; base_pfn -= nr_pages) { if (memtrace_offline_pages(nid, base_pfn, nr_pages) == true) { /* @@ -118,7 +120,6 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) * 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); @@ -127,6 +128,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) return base_pfn << PAGE_SHIFT; } } + unlock_device_hotplug(); return 0; } -- 2.17.1
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