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From: Wei Liu <wei.liu2@citrix.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Xen-devel <xen-devel@lists.xenproject.org>,
	Wei Liu <wei.liu2@citrix.com>,
	Ian Jackson <ian.jackson@eu.citrix.com>
Subject: Re: [XTF PATCH] xtf-runner: fix two synchronisation issues
Date: Fri, 29 Jul 2016 14:12:22 +0100	[thread overview]
Message-ID: <20160729131222.GE22419@citrix.com> (raw)
In-Reply-To: <783257c9-7f4c-587e-5e92-cee9711f0bcc@citrix.com>

On Fri, Jul 29, 2016 at 02:06:56PM +0100, Andrew Cooper wrote:
> On 29/07/16 13:58, Wei Liu wrote:
> > On Fri, Jul 29, 2016 at 01:43:42PM +0100, Andrew Cooper wrote:
> >> On 29/07/16 13:07, Wei Liu wrote:
> >>> There were two synchronisation issues for the old code:
> >>>
> >>> 1. There was no guarantee that guest console was ready before "xl
> >>>    console" invocation.
> >>> 2. There was no guarantee that runner wouldn't not exit before all test
> > s/not//
> >
> >>>    guests were gone.
> >> Sorry, but I can't parse this.
> >>
> >> The runner existing before xl has torn down the guest is very
> >> deliberate, because some part of hvm guests is terribly slow to tear
> >> down; waiting synchronously for teardown tripled the wallclock time to
> >> run a load of tests back-to-back.
> >>
> > Then you won't know if a guest is leaked or it is being slowly destroyed
> > when a dead guest shows up in the snapshot of 'xl list'.
> >
> > Also consider that would make back-to-back tests that happen to have a
> > guest that has the same name as the one in previous test fail.
> 
> test names are globally unique, so this isn't an issue.
> 
> Also, the wait for `xl console` to complete shows that @releasedomain
> has been fired for the domain.
> 

Are you suggesting waiting for "xl console" only is good enough?

> >
> > I don't think getting blocked for a few more seconds is a big issue.
> > It's is important to eliminate such race conditions so that osstest can
> > work properly.
> 
> Amortising the teardown cost in the background is fine (which is what
> your "for child in wait_list" ends up doing), but an extra few seconds
> per test is very important to be avoided for manual use of XTF.
> 

So let's default to not wait and add an option to wait. Osstest will use
that option.

Wei.

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  reply	other threads:[~2016-07-29 13:12 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-29 12:07 [XTF PATCH] xtf-runner: fix two synchronisation issues Wei Liu
2016-07-29 12:43 ` Andrew Cooper
2016-07-29 12:58   ` Wei Liu
2016-07-29 13:06     ` Andrew Cooper
2016-07-29 13:12       ` Wei Liu [this message]
2016-07-29 13:23         ` Andrew Cooper
2016-07-29 13:26           ` Wei Liu
2016-07-29 14:31     ` Ian Jackson
2016-07-29 14:55       ` Wei Liu
2016-07-29 16:18         ` Ian Jackson
2016-07-29 16:35           ` Andrew Cooper
2016-07-29 16:41           ` Wei Liu
2016-07-29 15:05       ` Andrew Cooper
2016-08-01 13:16       ` [RFC PATCH 0/8] Fix console " Wei Liu
2016-08-01 13:16         ` [RFC PATCH 1/8] tools/console: fix help string in client Wei Liu
2016-08-05 15:40           ` Ian Jackson
2016-08-01 13:16         ` [RFC PATCH 2/8] tools/console: introduce --start-notify-fd option for console client Wei Liu
2016-08-05 15:43           ` Ian Jackson
2016-08-01 13:16         ` [RFC PATCH 3/8] libxl: factor out libxl__console_tty_path Wei Liu
2016-08-05 15:44           ` Ian Jackson
2016-08-01 13:16         ` [RFC PATCH 4/8] libxl: wait up to 5s in libxl_console_exec for xenconsoled Wei Liu
2016-08-05 15:48           ` Ian Jackson
2016-08-01 13:16         ` [RFC PATCH 5/8] libxl: libxl_{primary_, }console_exec now take notify_fd argument Wei Liu
2016-08-05 15:49           ` Ian Jackson
2016-08-05 15:50             ` Ian Jackson
2016-08-01 13:16         ` [RFC PATCH 6/8] docs: document xenconsole startup protocol Wei Liu
2016-08-05 15:52           ` Ian Jackson
2016-08-01 13:16         ` [RFC PATCH 7/8] xl: use " Wei Liu
2016-08-05 15:55           ` Ian Jackson
2016-08-01 13:16         ` [RFC PATCH 8/8] tools/console: remove 5s bodge in console client Wei Liu
2016-08-05 15:57           ` Ian Jackson
2016-08-05 16:16             ` Wei Liu
2016-08-05 16:18               ` Ian Jackson
2016-08-05 16:28                 ` Wei Liu
2016-08-05 16:32                   ` Ian Jackson
2016-08-05 16:36                     ` Wei Liu
2016-08-05 17:23                       ` Wei Liu
2016-08-08 10:07                         ` Ian Jackson
2016-08-01 14:04       ` [XTF PATCH] xtf-runner: use xl create -Fc directly Wei Liu
2016-07-29 13:27 ` [XTF PATCH] xtf-runner: fix two synchronisation issues Andrew Cooper
2016-07-29 14:21 ` Ian Jackson
2016-07-29 14:25   ` Wei Liu
2016-07-29 14:35     ` Ian Jackson
2016-07-29 14:46       ` Wei Liu
2016-07-29 14:26   ` Andrew Cooper

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