Messages in this thread Patch in this message | | | Date | Tue, 24 Mar 2020 11:39:19 +0000 | From | Qais Yousef <> | Subject | Re: Hit WARN_ON() in rcutorture.c:1055 |
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On 03/23/20 11:44, Paul E. McKenney wrote: > > > > {register, unregister}_pm_notifier() don't seem to be too hard to use. > > > > > > That part is easy. It would also be necessary to find all the affected > > > warnings in rcutorture and suppress them, not only during this time, > > > but also for some period of time afterwards. Maybe this is the only one, > > > but that would be surprising. ;-) > > > > Wouldn't be easier to just deinit/init()? ie: treat it like unload/load module. > > > > But you'll lose some info then that maybe you'd like to keep across > > suspend/resume cycles. > > Hmmm... Are you running rcutorture as a loadable module or built into > your kernel? In the latter case, it starts up automatically shortly > after boot.
Built-in. Sorry maybe I wasn't clear. I meant something like the attached. Which still generates this warning, so yeah I get your point about suppressing some warnings in the right places now.
[ 48.898066] rcu-torture: Stopping rcu_torture_fwd_prog task [ 48.908998] rcu-torture: Stopping rcu_torture_reader [ 48.917052] rcu-torture: Stopping rcu_torture_fakewriter [ 48.926987] ------------[ cut here ]------------ [ 48.927025] WARNING: CPU: 4 PID: 261 at kernel/rcu/rcutorture.c:1085 rcu_torture_writer+0x49c/0xa90 [ 48.927038] rcu-torture: Stopping rcu_torture_fakewriter [ 48.927041] Modules linked in: [ 48.927070] CPU: 4 PID: 261 Comm: rcu_torture_wri Not tainted 5.6.0-rc6-00002-g533440e608d2-dirty #540 [ 48.927085] Hardware name: ARM Juno development board (r2) (DT) [ 48.927103] pstate: 00000005 (nzcv daif -PAN -UAO) [ 48.927124] pc : rcu_torture_writer+0x49c/0xa90 [ 48.927144] lr : rcu_torture_writer+0x494/0xa90 [ 48.927157] sp : ffff800018bfbde0 [ 48.927172] x29: ffff800018bfbde0 x28: ffff80001426da58 [ 48.927198] x27: ffff80001426cf08 x26: ffff80001426cf08 [ 48.927224] x25: ffff8000121b5000 x24: 0000000000000001 [ 48.927250] x23: ffff80001426d650 x22: ffff80001426b000 [ 48.927275] x21: ffff800013439000 x20: 0000000000000001 [ 48.927301] x19: ffff80001426c000 x18: 0000000000000000 [ 48.927326] x17: 0000000000000000 x16: 0000000000000000 [ 48.927351] x15: 0000000000000000 x14: 0000000000000000 [ 48.927376] x13: 0000000000000000 x12: 0000000000000000 [ 48.927401] x11: 00000000000001fa x10: 0000000000000000 [ 48.927426] x9 : ffff800013a130a0 x8 : ffff0009757f0850 [ 48.927450] x7 : 0000000000000000 x6 : ffff800018bfbcc0 [ 48.927475] x5 : 0000000000000001 x4 : 0000000000000000 [ 48.927499] x3 : 0000000000000080 x2 : 0000000000000000 [ 48.927524] x1 : 0000000000000000 x0 : 0000000000000001 [ 48.927548] Call trace: [ 48.927569] rcu_torture_writer+0x49c/0xa90 [ 48.927590] kthread+0x13c/0x140 [ 48.927611] ret_from_fork+0x10/0x18 [ 48.927627] irq event stamp: 34170 [ 48.927654] hardirqs last enabled at (34169): [<ffff800010114300>] __local_bh_enable_ip+0x98/0x148 [ 48.927680] hardirqs last disabled at (34170): [<ffff8000100a95d0>] do_debug_exception+0x1a8/0x258 [ 48.927702] softirqs last enabled at (34168): [<ffff8000101b949c>] rcu_torture_free+0x84/0x98 [ 48.927725] softirqs last disabled at (34166): [<ffff8000101b9478>] rcu_torture_free+0x60/0x98 [ 48.927740] ---[ end trace 57f88d092825f447 ]---
Thanks
-- Qais Yousef diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 1aeecc165b21..defad882b236 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -45,6 +45,7 @@ #include <linux/sched/sysctl.h> #include <linux/oom.h> #include <linux/tick.h> +#include <linux/suspend.h> #include "rcu.h" @@ -1628,7 +1629,7 @@ static int rcu_torture_stall(void *args) } /* Spawn CPU-stall kthread, if stall_cpu specified. */ -static int __init rcu_torture_stall_init(void) +static int rcu_torture_stall_init(void) { if (stall_cpu <= 0) return 0; @@ -2008,7 +2009,7 @@ static int rcu_torture_fwd_prog(void *args) } /* If forward-progress checking is requested and feasible, spawn the thread. */ -static int __init rcu_torture_fwd_prog_init(void) +static int rcu_torture_fwd_prog_init(void) { struct rcu_fwd *rfp; @@ -2359,7 +2360,7 @@ static void rcutorture_sync(void) cur_ops->sync(); } -static int __init +static int rcu_torture_init(void) { long i; @@ -2549,5 +2550,47 @@ rcu_torture_init(void) return firsterr; } -module_init(rcu_torture_init); -module_exit(rcu_torture_cleanup); +static int rcu_torture_notify(struct notifier_block *nb, + unsigned long mode, void *_unused) +{ + switch (mode) { + case PM_HIBERNATION_PREPARE: + case PM_SUSPEND_PREPARE: + pr_info("Shutdodwn rcu torture.."); + rcu_torture_cleanup(); + break; + + case PM_POST_RESTORE: + pr_info("Restart rcu torture.."); + rcu_torture_init(); + break; + } + + return 0; +} + +static struct notifier_block rcu_nb = { + .notifier_call = rcu_torture_notify +}; + +static int nb_failed; + +int rcu_torture_module_init(void) +{ + nb_failed = register_pm_notifier(&rcu_nb); + if (nb_failed) + pr_warn("Failed to register PM notifier"); + + return rcu_torture_init(); +} + +void rcu_torture_module_exit(void) +{ + if (!nb_failed) + unregister_pm_notifier(&rcu_nb); + + rcu_torture_cleanup(); +} + +module_init(rcu_torture_module_init); +module_exit(rcu_torture_module_exit); | |