From: Stefano Brivio <sbrivio@redhat.com>
To: passt-dev@passt.top
Subject: Re: Weird timeout issue with passt
Date: Thu, 23 Jun 2022 11:32:12 +0200 [thread overview]
Message-ID: <20220623113212.727162c6@elisabeth> (raw)
In-Reply-To: <YrQBOFWthrYYC31a@yekko>
[-- Attachment #1: Type: text/plain, Size: 2268 bytes --]
On Thu, 23 Jun 2022 15:59:20 +1000
David Gibson <david(a)gibson.dropbear.id.au> wrote:
> I alluded to this in my last patchset, but here's the information I've
> gathered on the current problem I'm hitting running the passt distro
> tests. It's pretty weird.
>
> On at least two occasions the tests have stalled during the Fedora 30,
> aarch64 test, with the guest getting a timeout downloading the package
> lists before installing new packages. For me this is selecting the
> mirror mirror.2degrees.nz. I'm not sure which factors are are
> relevant to reproducing the problem though.
>
> * The problem seems to me that the download suddenly stops progressing
> * partway through, causing dnf to eventually time out
>
> * If I manually try a "dnf clean all && dnf makecache -v" using the
> same guest image, it doesn't fail every time, but it fails
> significantly more often than not
>
> * It doesn't fail on the same file every time
>
> * I haven't been able to reproduce manually downloading the failing
> file with curl (tried repeatedly)
>
> * If I restrict dnf to a single repository rather than the whole set,
> I haven't managed to reproduce the problem
If I remember correctly, dnf downloads from multiple repositories at
the same time, which might explain these two points.
>
> * If I use qemu's -net user slirp instead of passt with the same disk
> image , I haven't been able to reproduce the problem (tried a bunch
> of times)
>
> * I've reproduced with the guest using both IPv4 and IPv6
>
> * I have reproduced what looks like the same problem with an x86 guest
> image under KVM (also Fedora 30), but it seems to happen much less
> often (seen once in 10 or more attempts)
>
> * Seems to reproduce fairly readily with an x86 guest under TCG
> though, so I'm guessing the difference is timing related.
...hmm, I never hit this, and I guess our versions of qemu eventually
crossed at some point -- I'm using 7.0.50 (v7.0.0-937-gd6900f445e)
right now.
Passing a capture file via --pcap for that instance of passt (started
at the beginning of fedora/tests) might help shine some light on this.
You could also add run ./test with PCAP=1, but that would capture
everything, which will take a ton of space.
--
Stefano
prev parent reply other threads:[~2022-06-23 9:32 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-23 5:59 Weird timeout issue with passt David Gibson
2022-06-23 9:32 ` Stefano Brivio [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220623113212.727162c6@elisabeth \
--to=sbrivio@redhat.com \
--cc=passt-dev@passt.top \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://passt.top/passt
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for IMAP folder(s).