Re: [PATCH v2 3/3] mm/memory_hotplug: fix unpaired mem_hotplug_begin/done
From: Michal Hocko <mhocko@kernel.org>
Date: 2020-07-07 10:06:23
Also in:
linux-mm, lkml, nvdimm, stable
On Tue 07-07-20 13:59:17, Jia He wrote:
When check_memblock_offlined_cb() returns failed rc(e.g. the memblock is
online at that time), mem_hotplug_begin/done is unpaired in such case.
Therefore a warning:
Call Trace:
percpu_up_write+0x33/0x40
try_remove_memory+0x66/0x120
? _cond_resched+0x19/0x30
remove_memory+0x2b/0x40
dev_dax_kmem_remove+0x36/0x72 [kmem]
device_release_driver_internal+0xf0/0x1c0
device_release_driver+0x12/0x20
bus_remove_device+0xe1/0x150
device_del+0x17b/0x3e0
unregister_dev_dax+0x29/0x60
devm_action_release+0x15/0x20
release_nodes+0x19a/0x1e0
devres_release_all+0x3f/0x50
device_release_driver_internal+0x100/0x1c0
driver_detach+0x4c/0x8f
bus_remove_driver+0x5c/0xd0
driver_unregister+0x31/0x50
dax_pmem_exit+0x10/0xfe0 [dax_pmem]
Fixes: f1037ec0cc8a ("mm/memory_hotplug: fix remove_memory() lockdep splat")
Cc: stable@vger.kernel.org # v5.6+
Signed-off-by: Jia He <redacted>Ups, I have missed that when reviewing that commit. Thanks for catching this up! Acked-by: Michal Hocko <mhocko@suse.com>
quoted hunk ↗ jump to hunk
--- mm/memory_hotplug.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index da374cd3d45b..76c75a599da3 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c@@ -1742,7 +1742,7 @@ static int __ref try_remove_memory(int nid, u64 start, u64 size) */ rc = walk_memory_blocks(start, size, NULL, check_memblock_offlined_cb); if (rc) - goto done; + return rc; /* remove memmap entry */ firmware_map_remove(start, start + size, "System RAM");@@ -1766,9 +1766,8 @@ static int __ref try_remove_memory(int nid, u64 start, u64 size) try_offline_node(nid); -done: mem_hotplug_done(); - return rc; + return 0; } /**-- 2.17.1
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