From: Olaf Hering <olaf@aepfle.de>
To: xen-devel@lists.xen.org
Subject: xl dev-detach hangs with missing frontends
Date: Thu, 11 Feb 2016 11:37:49 +0100 [thread overview]
Message-ID: <20160211103749.GA26883@aepfle.de> (raw)
How should libxl__initiate_device_generic_remove deal with devices which
have no frontend driver? Right now it moves "state" from either
XenbusStateInitialising or XenbusStateInitWait to XenbusStateClosing.
Then it expects the backend to move "state" to XenbusStateClosed. This
will never happen, at least for netback and scsiback. The result is a 10
second delay.
# xl -vvvv network-detach $domU $mac
2016-02-11 11:33:19 CET [20318] libxl: debug: libxl.c:4614:libxl_device_nic_remove: ao 0x19b3870: create: how=(nil) callback=(nil) poller=0x19b0200
2016-02-11 11:33:19 CET [20318] libxl: debug: libxl_event.c:636:libxl__ev_xswatch_register: watch w=0x19b2c40 wpath=/local/domain/0/backend/vif/10/1/state token=3/0: register slotnum=3
2016-02-11 11:33:19 CET [20318] libxl: debug: libxl.c:4614:libxl_device_nic_remove: ao 0x19b3870: inprogress: poller=0x19b0200, flags=i
2016-02-11 11:33:19 CET [20318] libxl: debug: libxl_event.c:573:watchfd_callback: watch w=0x19b2c40 wpath=/local/domain/0/backend/vif/10/1/state token=3/0: event epath=/local/domain/0/backend/vif/10/1/state
2016-02-11 11:33:19 CET [20318] libxl: debug: libxl_event.c:878:devstate_callback: backend /local/domain/0/backend/vif/10/1/state wanted state 6 still waiting state 5
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_aoutils.c:88:xswait_timeout_callback: backend /local/domain/0/backend/vif/10/1/state (hoping for state change to 6): xswait timeout (path=/local/domain/0/backend/vif/10/1/state)
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:673:libxl__ev_xswatch_deregister: watch w=0x19b2c40 wpath=/local/domain/0/backend/vif/10/1/state token=3/0: deregister slotnum=3
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:862:devstate_callback: backend /local/domain/0/backend/vif/10/1/state wanted state 6 timed out
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:686:libxl__ev_xswatch_deregister: watch w=0x19b2c40: deregister unregistered
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_device.c:939:device_backend_callback: calling device_backend_cleanup
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:686:libxl__ev_xswatch_deregister: watch w=0x19b2c40: deregister unregistered
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_device.c:945:device_backend_callback: Timeout reached, initiating forced remove
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:636:libxl__ev_xswatch_register: watch w=0x19b2c40 wpath=/local/domain/0/backend/vif/10/1/state token=3/1: register slotnum=3
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:573:watchfd_callback: watch w=0x19b2c40 wpath=/local/domain/0/backend/vif/10/1/state token=3/1: event epath=/local/domain/0/backend/vif/10/1/state
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:874:devstate_callback: backend /local/domain/0/backend/vif/10/1/state wanted state 6 ok
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:673:libxl__ev_xswatch_deregister: watch w=0x19b2c40 wpath=/local/domain/0/backend/vif/10/1/state token=3/1: deregister slotnum=3
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_device.c:939:device_backend_callback: calling device_backend_cleanup
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:686:libxl__ev_xswatch_deregister: watch w=0x19b2c40: deregister unregistered
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_device.c:1036:device_hotplug: calling hotplug script: /opt/xen/staging-wip/etc/xen/scripts/vif-bridge offline
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_aoutils.c:593:libxl__async_exec_start: forking to execute: /opt/xen/staging-wip/etc/xen/scripts/vif-bridge offline
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:542:watchfd_callback: watch epath=/local/domain/0/backend/vif/10/1/state token=3/1: empty slot
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:686:libxl__ev_xswatch_deregister: watch w=0x19b2d40: deregister unregistered
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_device.c:1023:device_hotplug: No hotplug script to execute
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:686:libxl__ev_xswatch_deregister: watch w=0x19b2d40: deregister unregistered
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:1869:libxl__ao_complete: ao 0x19b3870: complete, rc=0
2016-02-11 11:33:29 CET [20318] libxl: debug: libxl_event.c:1838:libxl__ao__destroy: ao 0x19b3870: destroy
2016-02-11 11:33:29 CET [20318] xencall:buffer: debug: total allocations:22 total releases:22
2016-02-11 11:33:29 CET [20318] xencall:buffer: debug: current allocations:0 maximum allocations:2
2016-02-11 11:33:29 CET [20318] xencall:buffer: debug: cache current size:2
2016-02-11 11:33:29 CET [20318] xencall:buffer: debug: cache hits:14 misses:2 toobig:6
# echo $?
0
At least ${dev}-detach reports no error in this case.
Olaf
next reply other threads:[~2016-02-11 10:37 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-11 10:37 Olaf Hering [this message]
2016-02-12 14:07 ` xl dev-detach hangs with missing frontends Wei Liu
2016-02-12 14:53 ` Olaf Hering
2016-02-12 16:56 ` Wei Liu
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