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| author | Michal Hocko <mhocko@suse.com> | 2018-11-02 15:48:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-11-03 10:09:38 -0700 |
| commit | dd33ad7b251f900481701b2a82d25de583867708 (patch) | |
| tree | 388031c740f221576e7bb3f1ad35b0b158280525 /mm | |
| parent | 9f2df09a33aa2c76ce6385d382693f98d7f2f07e (diff) | |
| download | lwn-dd33ad7b251f900481701b2a82d25de583867708.tar.gz lwn-dd33ad7b251f900481701b2a82d25de583867708.zip | |
memory_hotplug: cond_resched in __remove_pages
We have received a bug report that unbinding a large pmem (>1TB) can
result in a soft lockup:
NMI watchdog: BUG: soft lockup - CPU#9 stuck for 23s! [ndctl:4365]
[...]
Supported: Yes
CPU: 9 PID: 4365 Comm: ndctl Not tainted 4.12.14-94.40-default #1 SLE12-SP4
Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018
task: ffff9cce7d4410c0 task.stack: ffffbe9eb1bc4000
RIP: 0010:__put_page+0x62/0x80
Call Trace:
devm_memremap_pages_release+0x152/0x260
release_nodes+0x18d/0x1d0
device_release_driver_internal+0x160/0x210
unbind_store+0xb3/0xe0
kernfs_fop_write+0x102/0x180
__vfs_write+0x26/0x150
vfs_write+0xad/0x1a0
SyS_write+0x42/0x90
do_syscall_64+0x74/0x150
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x7fd13166b3d0
It has been reported on an older (4.12) kernel but the current upstream
code doesn't cond_resched in the hot remove code at all and the given
range to remove might be really large. Fix the issue by calling
cond_resched once per memory section.
Link: http://lkml.kernel.org/r/20181031125840.23982-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Dan Williams <dan.j.williams@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory_hotplug.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 61972da38d93..2b2b3ccbbfb5 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -586,6 +586,7 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, for (i = 0; i < sections_to_remove; i++) { unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; + cond_resched(); ret = __remove_section(zone, __pfn_to_section(pfn), map_offset, altmap); map_offset = 0; |