Commits
Steven J. Hill committed c7f26ccfb2c
mm/vmstat.c: fix vmstat_update() preemption BUG
Attempting to hotplug CPUs with CONFIG_VM_EVENT_COUNTERS enabled can
cause vmstat_update() to report a BUG due to preemption not being
disabled around smp_processor_id().
Discovered on Ubiquiti EdgeRouter Pro with Cavium Octeon II processor.
BUG: using smp_processor_id() in preemptible [00000000] code:
kworker/1:1/269
caller is vmstat_update+0x50/0xa0
CPU: 0 PID: 269 Comm: kworker/1:1 Not tainted
4.16.0-rc4-Cavium-Octeon-00009-gf83bbd5-dirty #1
Workqueue: mm_percpu_wq vmstat_update
Call Trace:
show_stack+0x94/0x128
dump_stack+0xa4/0xe0
check_preemption_disabled+0x118/0x120
vmstat_update+0x50/0xa0
process_one_work+0x144/0x348
worker_thread+0x150/0x4b8
kthread+0x110/0x140
ret_from_kernel_thread+0x14/0x1c
Link: http://lkml.kernel.org/r/1520881552-25659-1-git-send-email-steven.hill@cavium.com
Signed-off-by: Steven J. Hill <steven.hill@cavium.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>