From: David Hildenbrand <david@redhat.com>
To: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org,
xen-devel@lists.xenproject.org, devel@linuxdriverproject.org,
David Hildenbrand <david@redhat.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Rashmica Gupta <rashmica.g@gmail.com>,
Balbir Singh <bsingharora@gmail.com>,
Michael Neuling <mikey@neuling.org>
Subject: [PATCH v2 5/6] powerpc/powernv: hold device_hotplug_lock when calling memtrace_offline_pages()
Date: Tue, 25 Sep 2018 11:14:56 +0200 [thread overview]
Message-ID: <20180925091457.28651-6-david@redhat.com> (raw)
In-Reply-To: <20180925091457.28651-1-david@redhat.com>
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>
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..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
next prev parent reply other threads:[~2018-09-25 9:15 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-25 9:14 [PATCH v2 0/6] mm: online/offline_pages called w.o. mem_hotplug_lock David Hildenbrand
2018-09-25 9:14 ` [PATCH v2 1/6] mm/memory_hotplug: make remove_memory() take the device_hotplug_lock David Hildenbrand
2018-09-25 9:14 ` [PATCH v2 2/6] mm/memory_hotplug: make add_memory() " David Hildenbrand
2018-09-25 9:14 ` [PATCH v2 3/6] mm/memory_hotplug: fix online/offline_pages called w.o. mem_hotplug_lock David Hildenbrand
2018-09-25 9:14 ` [PATCH v2 4/6] powerpc/powernv: hold device_hotplug_lock when calling device_online() David Hildenbrand
2018-09-25 9:14 ` David Hildenbrand [this message]
2018-09-25 12:15 ` [PATCH v2 5/6] powerpc/powernv: hold device_hotplug_lock when calling memtrace_offline_pages() Balbir Singh
2018-09-26 10:09 ` David Hildenbrand
2018-09-25 9:14 ` [PATCH v2 6/6] memory-hotplug.txt: Add some details about locking internals David Hildenbrand
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