Re: [OSSTEST PATCH 7/7] make-flight: Stripy xenstored [and 2 more messages]

From: Ian Jackson <iwj@xenproject.org>
To: Edwin Torok <edvin.torok@citrix.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>
Cc: xen-devel@lists.xenproject.org,
	"Christian Lindig" <christian.lindig@citrix.com>,
	"Jürgen Groß" <jgross@suse.com>, "Wei Liu" <wl@xen.org>
Subject: Re: [OSSTEST PATCH 7/7] make-flight: Stripy xenstored [and 2 more messages]
Date: Fri, 22 Jan 2021 17:37:12 +0000	[thread overview]
Message-ID: <24587.3400.673049.196349@mariner.uk.xensource.com> (raw)
In-Reply-To: <a436baeb-888e-a213-2a68-6817309a6b2a@citrix.com>, <81f92e66-3a43-dea8-f633-2fcf725c10dc@citrix.com>, <8b231075e5ed13412f98881c3b3454d9abf9e871.camel@citrix.com>

Andrew Cooper writes ("Re: [OSSTEST PATCH 7/7] make-flight: Stripy xenstored"):
> Right, but nothing will actually fail the build.

Indeed.

> So the way this error will manifest is the first non-trivial `xl $FOO`
> executed in dom0 hanging until the job timeout.

I doubt it would produce a timeout BICBW.

> Or does OSSTest have an explicit "is xenstored running" check after
> boot, before any further testing occurs?

No.

If this turns out to ever happen we can improve the pre-checking.  In
general I let the chips fall where they may, for test failures, and
improve the checking/logging later.  Otherwise adding new tests
becomes very time-consuming (and there is also the risk that added
checks do not align with actual behvaiour).

Now that it's builing, I think it's fairly unlikely that we will
accidentally stop building one of the xenstoreds.

> There is no such thing as an ocaml stub-xenstored yet, but I have asked
> the Mirage folk if they'd like to remedy this.

Cool.

Andrew Cooper writes ("Re: [OSSTEST PATCH 7/7] make-flight: Stripy xenstored"):
> An extra thought.  What exactly feeds into the decision?

Precisely, the job name.

> If it includes the flight number, then the retest logic is going to get
> very confused on xenstored bugs when the implementation change between
> the two runs.

Indeed.  But it doesn't :-).

> Also, what is the bisector going across this changeset?

The bisector always runs with the latest osstest.  So if this new C
xenstore testing discovers that it's broken, the bisector won't be
much help.  (It will fail to repro the basis pass; so in any case we
won't get false reports from it.)

On the other hand, if C xenstored still works and some future point we
break it, the bisection will DTRT.

Edwin Torok writes ("Re: [OSSTEST PATCH 7/7] make-flight: Stripy xenstored"):
> In the patch series that I've recently posted to xen-devel there is
> also a 'make check' target in tools/ocaml/xenstored.

Cool.

Thanks,
Ian.