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Subject: Re: ARM/gic-v4: deadlock occurred
To:     Marc Zyngier <marc.zyngier@arm.com>
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CC:     <linux-kernel@vger.kernel.org>,
        wanghaibin 00208455 <wanghaibin.wang@huawei.com>,
        kvmarm <kvmarm@lists.cs.columbia.edu>
From:   Heyi Guo <guoheyi@huawei.com>
Message-ID: <8be3a9f0-f3c5-8874-e7f4-9fc507925153@huawei.com>
Date:   Thu, 9 May 2019 19:37:28 +0800
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On 2019/5/9 15:48, Marc Zyngier wrote:
> Hi Heyi,
>
> On Wed, 08 May 2019 14:01:48 +0100,
> Heyi Guo <guoheyi@huawei.com> wrote:
>> Hi Marc,
>>
>> The bad news is that though your previous patch fixed the lockdep
>> warnings, we can still reproduce soft lockup panics and some other
>> exceptions... So our issue may not be related with this lock defect.
>>
>> Most of the call traces are as below, stuck in smp_call_function_many:
>>
>> [ 6862.660611] watchdog: BUG: soft lockup - CPU#27 stuck for 23s! [CPU 18/KVM:95311]
>> [ 6862.668283] Modules linked in: ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter vport_vxlan vxlan ip6_udp_tunnel udp_tunnel openvswitch nsh nf_nat_ipv6 nf_nat_ipv4 nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ib_isert iscsi_target_mod ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib ib_umad rpcrdma sunrpc rdma_ucm ib_uverbs ib_iser rdma_cm iw_cm ib_cm hns_roce_hw_v2 hns_roce aes_ce_blk crypto_simd ib_core cryptd aes_ce_cipher crc32_ce ghash_ce sha2_ce sha256_arm64 sha1_ce marvell ses enclosure hibmc_drm ttm drm_kms_helper drm sg ixgbe mdio fb_sys_fops syscopyarea hns3 hclge sysfillrect hnae3 sysimgblt sbsa_gwdt vhost_net tun vhost tap ip_tables dm_mod megaraid_sas hisi_sas_v3_hw hisi_sas_main ipmi_si ipmi_devintf ipmi_msghandler br_netfilter xt_sctp
>> [ 6862.668519] irq event stamp: 1670812
>> [ 6862.668526] hardirqs last  enabled at (1670811): [<ffff000008083498>] el1_irq+0xd8/0x180
>> [ 6862.668530] hardirqs last disabled at (1670812): [<ffff000008083448>] el1_irq+0x88/0x180
>> [ 6862.668534] softirqs last  enabled at (1661542): [<ffff000008081d2c>] __do_softirq+0x41c/0x51c
>> [ 6862.668539] softirqs last disabled at (1661535): [<ffff0000080fafc4>] irq_exit+0x18c/0x198
>> [ 6862.668544] CPU: 27 PID: 95311 Comm: CPU 18/KVM Kdump: loaded Tainted: G        W         4.19.36-1.2.141.aarch64 #1
>> [ 6862.668548] Hardware name: Huawei TaiShan 2280 V2/BC82AMDA, BIOS TA BIOS TaiShan 2280 V2 - B900 01/29/2019
>> [ 6862.668551] pstate: 80400009 (Nzcv daif +PAN -UAO)
>> [ 6862.668557] pc : smp_call_function_many+0x360/0x3b8
>> [ 6862.668560] lr : smp_call_function_many+0x320/0x3b8
>> [ 6862.668563] sp : ffff000028f338e0
>> [ 6862.668566] x29: ffff000028f338e0 x28: ffff000009893fb4
>> [ 6862.668575] x27: 0000000000000400 x26: 0000000000000000
>> [ 6862.668583] x25: ffff0000080b1e08 x24: 0000000000000001
>> [ 6862.668591] x23: ffff000009891bc8 x22: ffff000009891bc8
>> [ 6862.668599] x21: ffff805f7d6da408 x20: ffff000009893fb4
>> [ 6862.668608] x19: ffff805f7d6da400 x18: 0000000000000000
>> [ 6862.668616] x17: 0000000000000000 x16: 0000000000000000
>> [ 6862.668624] x15: 0000000000000000 x14: 0000000000000000
>> [ 6862.668632] x13: 0000000000000040 x12: 0000000000000228
>> [ 6862.668640] x11: 0000000000000020 x10: 0000000000000040
>> [ 6862.668648] x9 : 0000000000000000 x8 : 0000000000000010
>> [ 6862.668656] x7 : 0000000000000000 x6 : ffff805f7d329660
>> [ 6862.668664] x5 : ffff000028f33850 x4 : 0000000002000402
>> [ 6862.668673] x3 : 0000000000000000 x2 : ffff803f7f3dc678
>> [ 6862.668681] x1 : 0000000000000003 x0 : 000000000000000a
>> [ 6862.668689] Call trace:
>> [ 6862.668693]  smp_call_function_many+0x360/0x3b8
> This would tend to indicate that one of the CPUs isn't responding to
> the IPI because it has its interrupts disabled, or has crashed badly
> already. Can you check where in smp_call_function_many this is
> hanging? My bet is on the wait loop at the end of the function.

Yes.

>
> You'll need to find out what this unresponsive CPU is doing...

True; we need to dig more deeply...

Appreciate it.

Heyi

>
>> Any idea is appreciated.
>>
>> We will find some time and board to test your new patch set, but
>> right now our top priority is to debug the above issue, so it may
>> take some time to get back with the test result. Sorry for that.
> No worries, that can wait.
>
> 	M.
>