[PATCH v2 5/6] powerpc/powernv: hold device_hotplug_lock when calling memtrace_offline_pages()
From: David Hildenbrand <hidden>
Date: 2018-09-25 09:15:50
Also in:
linux-doc, linux-mm, linuxppc-dev, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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 <redacted> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rashmica Gupta <redacted> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Michael Neuling <redacted> Reviewed-by: Pavel Tatashin <redacted> Reviewed-by: Rashmica Gupta <redacted> Signed-off-by: David Hildenbrand <redacted> --- 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..d84d09c56af9 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;
@@ -111,6 +112,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) 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, 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);
@@ -126,6 +127,7 @@ static u64 memtrace_alloc_node(u32 nid, u64 size) unlock_device_hotplug(); return base_pfn << PAGE_SHIFT; } + unlock_device_hotplug(); } return 0;
--
2.17.1