On Mon, Jan 7, 2019 at 11:19 AM Dave Jones <da...@codemonkey.org.uk> wrote:
>
> [ 32.845071] =============================
> [ 32.845084] WARNING: suspicious RCU usage
> [ 32.845098] 5.0.0-rc1-backup+ #1 Not tainted
> [ 32.845111] -----------------------------
> [ 32.845124] ./include/linux/rcupdate.h:281 Illegal context switch in RCU
> read-side critical section!
> [ 32.845164]
> other info that might help us debug this:
>
> [ 32.845194]
> rcu_scheduler_active = 2, debug_locks = 1
> [ 32.845214] 6 locks held by ifenslave/645:
> [ 32.845227] #0: 000000004ce34177 (sb_writers#6){.+.+}, at:
> vfs_write+0x189/0x1b0
> [ 32.845255] #1: 0000000045fc0eaf (&of->mutex){+.+.}, at:
> kernfs_fop_write+0xdf/0x190
> [ 32.845281] #2: 000000005e42d596 (kn->count#116){.+.+}, at:
> kernfs_fop_write+0xe8/0x190
> [ 32.845307] #3: 000000006f123b98 (rtnl_mutex){+.+.}, at:
> bond_opt_tryset_rtnl+0x2a/0x90
> [ 32.845333] #4: 00000000cdbe39f8 (&(&bond->stats_lock)->rlock#2/2){+.+.},
> at: bond_get_stats+0x4d/0x200
> [ 32.845361] #5: 00000000323ba386 (rcu_read_lock){....}, at:
> bond_get_stats+0x5/0x200
> [ 32.845385]
> stack backtrace:
> [ 32.845401] CPU: 6 PID: 645 Comm: ifenslave Not tainted 5.0.0-rc1-backup+
> #1
> [ 32.845419] Hardware name: ASUS All Series/Z97-DELUXE, BIOS 2602 08/18/2015
> [ 32.845437] Call Trace:
> [ 32.845448] dump_stack+0x5f/0x8b
> [ 32.845462] ___might_sleep.part.95+0xd8/0x230
> [ 32.845478] __mutex_lock+0x60/0x980
> [ 32.845491] ? _raw_spin_unlock+0x24/0x30
> [ 32.845506] ? igb_get_stats64+0x29/0x60
> [ 32.845519] ? lock_acquire+0xa1/0x196
> [ 32.845533] ? e1000e_get_stats64+0x1e/0x120
> [ 32.845547] ? igb_get_stats64+0x29/0x60
> [ 32.845559] igb_get_stats64+0x29/0x60
Introduced by
commit 59361316afcb08569af21e1af83e89c7051c055a
Author: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
Date: Thu Aug 2 10:13:10 2018 -0700
igb: reduce CPU0 latency when updating statistics
