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| author | Steven J. Hill <steven.hill@cavium.com> | 2018-03-28 16:01:09 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-03-28 13:42:05 -1000 |
| commit | c7f26ccfb2c31eb1bf810ba13d044fcf583232db (patch) | |
| tree | 394207a8faa79d45f9d0a85b9fc90af19d65eca3 /mm/vmstat.c | |
| parent | 299815a4fba9f3c7a81434dba0072148f1690608 (diff) | |
| download | linux-c7f26ccfb2c31eb1bf810ba13d044fcf583232db.tar.gz linux-c7f26ccfb2c31eb1bf810ba13d044fcf583232db.tar.bz2 linux-c7f26ccfb2c31eb1bf810ba13d044fcf583232db.zip | |
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>
Diffstat (limited to 'mm/vmstat.c')
| -rw-r--r-- | mm/vmstat.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/vmstat.c b/mm/vmstat.c index 40b2db6db6b1..33581be705f0 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1839,9 +1839,11 @@ static void vmstat_update(struct work_struct *w) * to occur in the future. Keep on running the * update worker thread. */ + preempt_disable(); queue_delayed_work_on(smp_processor_id(), mm_percpu_wq, this_cpu_ptr(&vmstat_work), round_jiffies_relative(sysctl_stat_interval)); + preempt_enable(); } } |