linux/dim: Fix divide by 0 in RDMA DIM
commit
0fe3dbbefb74a8575f61d7801b08dbc50523d60d upstream.
Fix a divide 0 error in rdma_dim_stats_compare() when prev->cpe_ratio ==
0.
CallTrace:
Hardware name: H3C R4900 G3/RS33M2C9S, BIOS 2.00.37P21 03/12/2020
task:
ffff880194b78000 task.stack:
ffffc90006714000
RIP: 0010:backport_rdma_dim+0x10e/0x240 [mlx_compat]
RSP: 0018:
ffff880c10e83ec0 EFLAGS:
00010202
RAX:
0000000000002710 RBX:
ffff88096cd7f780 RCX:
0000000000000064
RDX:
0000000000000000 RSI:
0000000000000002 RDI:
0000000000000001
RBP:
0000000000000001 R08:
0000000000000000 R09:
0000000000000000
R10:
0000000000000000 R11:
0000000000000000 R12:
000000001d7c6c09
R13:
ffff88096cd7f780 R14:
ffff880b174fe800 R15:
0000000000000000
FS:
0000000000000000(0000) GS:
ffff880c10e80000(0000)
knlGS:
0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
CR2:
00000000a0965b00 CR3:
000000000200a003 CR4:
00000000007606e0
DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
PKRU:
55555554
Call Trace:
<IRQ>
ib_poll_handler+0x43/0x80 [ib_core]
irq_poll_softirq+0xae/0x110
__do_softirq+0xd1/0x28c
irq_exit+0xde/0xf0
do_IRQ+0x54/0xe0
common_interrupt+0x8f/0x8f
</IRQ>
? cpuidle_enter_state+0xd9/0x2a0
? cpuidle_enter_state+0xc7/0x2a0
? do_idle+0x170/0x1d0
? cpu_startup_entry+0x6f/0x80
? start_secondary+0x1b9/0x210
? secondary_startup_64+0xa5/0xb0
Code: 0f 87 e1 00 00 00 8b 4c 24 14 44 8b 43 14 89 c8 4d 63 c8 44 29 c0 99 31 d0 29 d0 31 d2 48 98 48 8d 04 80 48 8d 04 80 48 c1 e0 02 <49> f7 f1 48 83 f8 0a 0f 86 c1 00 00 00 44 39 c1 7f 10 48 89 df
RIP: backport_rdma_dim+0x10e/0x240 [mlx_compat] RSP:
ffff880c10e83ec0
Fixes:
f4915455dcf0 ("linux/dim: Implement RDMA adaptive moderation (DIM)")
Link: https://lore.kernel.org/r/20220627140004.3099-1-thomas.liu@ucloud.cn
Signed-off-by: Tao Liu <thomas.liu@ucloud.cn>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Acked-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>