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net/page_pool: Fix inconsistent lock state warning
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Fix the warning below by calling the ptr_ring_consume_bh,
which uses spin_[un]lock_bh.

[  179.064300] ================================
[  179.069073] WARNING: inconsistent lock state
[  179.073846] 4.18.0-rc2+ #18 Not tainted
[  179.078133] --------------------------------
[  179.082907] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[  179.089637] swapper/21/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
[  179.095478] 00000000963d1995 (&(&r->consumer_lock)->rlock){+.?.}, at:
__page_pool_empty_ring+0x61/0x100
[  179.105988] {SOFTIRQ-ON-W} state was registered at:
[  179.111443]   _raw_spin_lock+0x35/0x50
[  179.115634]   __page_pool_empty_ring+0x61/0x100
[  179.120699]   page_pool_destroy+0x32/0x50
[  179.125204]   mlx5e_free_rq+0x38/0xc0 [mlx5_core]
[  179.130471]   mlx5e_close_channel+0x20/0x120 [mlx5_core]
[  179.136418]   mlx5e_close_channels+0x26/0x40 [mlx5_core]
[  179.142364]   mlx5e_close_locked+0x44/0x50 [mlx5_core]
[  179.148509]   mlx5e_close+0x42/0x60 [mlx5_core]
[  179.153936]   __dev_close_many+0xb1/0x120
[  179.158749]   dev_close_many+0xa2/0x170
[  179.163364]   rollback_registered_many+0x148/0x460
[  179.169047]   rollback_registered+0x56/0x90
[  179.174043]   unregister_netdevice_queue+0x7e/0x100
[  179.179816]   unregister_netdev+0x18/0x20
[  179.184623]   mlx5e_remove+0x2a/0x50 [mlx5_core]
[  179.190107]   mlx5_remove_device+0xe5/0x110 [mlx5_core]
[  179.196274]   mlx5_unregister_interface+0x39/0x90 [mlx5_core]
[  179.203028]   cleanup+0x5/0xbfc [mlx5_core]
[  179.208031]   __x64_sys_delete_module+0x16b/0x240
[  179.213640]   do_syscall_64+0x5a/0x210
[  179.218151]   entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  179.224218] irq event stamp: 334398
[  179.228438] hardirqs last  enabled at (334398): [<ffffffffa511d8b7>]
rcu_process_callbacks+0x1c7/0x790
[  179.239178] hardirqs last disabled at (334397): [<ffffffffa511d872>]
rcu_process_callbacks+0x182/0x790
[  179.249931] softirqs last  enabled at (334386): [<ffffffffa509732e>] irq_enter+0x5e/0x70
[  179.259306] softirqs last disabled at (334387): [<ffffffffa509741c>] irq_exit+0xdc/0xf0
[  179.268584]
[  179.268584] other info that might help us debug this:
[  179.276572]  Possible unsafe locking scenario:
[  179.276572]
[  179.283877]        CPU0
[  179.286954]        ----
[  179.290033]   lock(&(&r->consumer_lock)->rlock);
[  179.295546]   <Interrupt>
[  179.298830]     lock(&(&r->consumer_lock)->rlock);
[  179.304550]
[  179.304550]  *** DEADLOCK ***

Fixes: ff7d6b2 ("page_pool: refurbish version of page_pool code")
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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@davem330
Tariq Toukan authored and davem330 committed Jul 20, 2018
1 parent f39f28f commit 4905bd9
Showing 1 changed file with 1 addition and 1 deletion.
2 changes: 1 addition & 1 deletion net/core/page_pool.c
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Original file line number Diff line number Diff line change
Expand Up @@ -269,7 +269,7 @@ static void __page_pool_empty_ring(struct page_pool *pool)
struct page *page;

/* Empty recycle ring */
while ((page = ptr_ring_consume(&pool->ring))) {
while ((page = ptr_ring_consume_bh(&pool->ring))) {
/* Verify the refcnt invariant of cached pages */
if (!(page_ref_count(page) == 1))
pr_crit("%s() page_pool refcnt %d violation\n",
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