Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <56576c3c-fe9b-59cf-95b8-158734320f24@linux.ibm.com>
Date:   Fri, 23 Sep 2022 09:53:46 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.13.0
Subject: Re: [PATCH v3 6/6] freezer,sched: Rewrite core freezer logic
Content-Language: en-US
To:     peterz@infradead.org
Cc:     bigeasy@linutronix.de, dietmar.eggemann@arm.com,
        ebiederm@xmission.com, linux-kernel@vger.kernel.org,
        linux-pm@vger.kernel.org, mgorman@suse.de, mingo@kernel.org,
        oleg@redhat.com, rjw@rjwysocki.net, rostedt@goodmis.org,
        tj@kernel.org, vincent.guittot@linaro.org, will@kernel.org,
        Marc Hartmayer <mhartmay@linux.ibm.com>
References: <20220822114649.055452969@infradead.org>
 <20220923072104.2013212-1-borntraeger@linux.ibm.com>
From:   Christian Borntraeger <borntraeger@linux.ibm.com>
In-Reply-To: <20220923072104.2013212-1-borntraeger@linux.ibm.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

Am 23.09.22 um 09:21 schrieb Christian Borntraeger:
> Peter,
> 
> as a heads-up. This commit (bisected and verified) triggers a
> regression in our KVM on s390x CI. The symptom is that a specific
> testcase (start a guest with next kernel and a poky ramdisk,
> then ssh via vsock into the guest and run the reboot command) now
> takes much longer (300 instead of 20 seconds). From a first look
> it seems that the sshd takes very long to end during shutdown
> but I have not looked into that yet.
> Any quick idea?
> 
> Christian

the sshd seems to hang in virtio-serial (not vsock).

PID: 237      TASK: 81d1a100          CPU: 1    COMMAND: "sshd"
  LOWCORE INFO:
   -psw      : 0x0404e00180000000 0x0000000131ceb136
   -function : __list_add_valid at 131ceb136
   -prefix   : 0x00410000
   -cpu timer: 0x7fffffd3ec4f33d4
   -clock cmp: 0x2639f08006283e00
   -general registers:
      0x00000008dcea2dce 0x00000001387d44b8
      0x0000000081d1a228 0x00000001387d44b8
      0x00000001387d44b8 0x00000001387d44b8
      0x00000001387d3800 0x00000001387d3700
      0x0000000081d1a100 0x00000001387d44b8
      0x00000001387d44b8 0x0000000081d1a228
      0x0000000081d1a100 0x0000000081d1a100
      0x0000000131608b32 0x00000380004b7aa8
   -access registers:
      0x000003ff 0x8fff5870 0000000000 0000000000
      0000000000 0000000000 0000000000 0000000000
      0000000000 0000000000 0000000000 0000000000
      0000000000 0000000000 0000000000 0000000000
   -control registers:
      0x00a0000014966a10 0x0000000133348007
      0x00000000028c6140 000000000000000000
      0x000000000000ffff 0x00000000028c6140
      0x0000000033000000 0x0000000081f001c7
      0x0000000000008000 000000000000000000
      000000000000000000 000000000000000000
      000000000000000000 0x0000000133348007
      0x00000000db000000 0x00000000028c6000
   -floating point registers:
      0x000003ffb82a9761 0x0000006400000000
      0x000003ffb82a345c 000000000000000000
      0x0000000000007fff 0x000003ffe22fe000
      000000000000000000 0x000003ffe22fa51c
      0x000003ffb81889c0 000000000000000000
      0x000002aa3ce2b470 000000000000000000
      000000000000000000 000000000000000000
      000000000000000000 000000000000000000

  #0 [380004b7b00] pick_next_task at 1315f2088
  #1 [380004b7b98] __schedule at 13215e954
  #2 [380004b7c08] schedule at 13215eeea
  #3 [380004b7c38] wait_port_writable at 3ff80149b2e [virtio_console]
  #4 [380004b7cc0] port_fops_write at 3ff8014a282 [virtio_console]
  #5 [380004b7d40] vfs_write at 131889e3c
  #6 [380004b7e00] ksys_write at 13188a2e8
  #7 [380004b7e50] __do_syscall at 13215761c
  #8 [380004b7e98] system_call at 132166332
  PSW:  0705000180000000 000003ff8f8f3a2a (user space)
  GPRS: 0000000000000015 000003ff00000000 ffffffffffffffda 000002aa02fc68a0
        0000000000000015 0000000000000015 0000000000000000 000002aa02fc68a0
        0000000000000004 000003ff8f8f3a08 0000000000000015 0000000000000000
        000003ff8ffa9f58 0000000000000000 000002aa02365b20 000003ffdf4798d0