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| author | Paul E. McKenney <paulmck@linux.ibm.com> | 2018-12-10 18:44:52 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-01-26 00:37:10 +0100 |
| commit | 3a6cb58f159e64241b2af9374acad41a70939349 (patch) | |
| tree | ada940f453392a61ee945b23974647841ee65700 /kernel/torture.c | |
| parent | torture: Explain and simplify odd "for" loop in mkinitrd.sh (diff) | |
| download | linux-3a6cb58f159e64241b2af9374acad41a70939349.tar.xz linux-3a6cb58f159e64241b2af9374acad41a70939349.zip | |
rcutorture: Add grace period after CPU offline
Beyond a certain point in the CPU-hotplug offline process, timers get
stranded on the outgoing CPU, and won't fire until that CPU comes back
online, which might well be never. This commit therefore adds a hook
in torture_onoff_init() that is invoked from torture_offline(), which
rcutorture uses to occasionally wait for a grace period. This should
result in failures for RCU implementations that rely on stranded timers
eventually firing in the absence of the CPU coming back online.
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'kernel/torture.c')
| -rw-r--r-- | kernel/torture.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/torture.c b/kernel/torture.c index bbf6d473e50c..a03ff722352b 100644 --- a/kernel/torture.c +++ b/kernel/torture.c @@ -75,6 +75,7 @@ static DEFINE_MUTEX(fullstop_mutex); static struct task_struct *onoff_task; static long onoff_holdoff; static long onoff_interval; +static torture_ofl_func *onoff_f; static long n_offline_attempts; static long n_offline_successes; static unsigned long sum_offline; @@ -118,6 +119,8 @@ bool torture_offline(int cpu, long *n_offl_attempts, long *n_offl_successes, pr_alert("%s" TORTURE_FLAG "torture_onoff task: offlined %d\n", torture_type, cpu); + if (onoff_f) + onoff_f(); (*n_offl_successes)++; delta = jiffies - starttime; *sum_offl += delta; @@ -243,11 +246,12 @@ stop: /* * Initiate online-offline handling. */ -int torture_onoff_init(long ooholdoff, long oointerval) +int torture_onoff_init(long ooholdoff, long oointerval, torture_ofl_func *f) { #ifdef CONFIG_HOTPLUG_CPU onoff_holdoff = ooholdoff; onoff_interval = oointerval; + onoff_f = f; if (onoff_interval <= 0) return 0; return torture_create_kthread(torture_onoff, NULL, onoff_task); |