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socket: 0.629
instruction: 0.629
device: 0.625
network: 0.610
graphic: 0.599
other: 0.574
semantic: 0.546
mistranslation: 0.517
boot: 0.491
vnc: 0.477
assembly: 0.473
KVM: 0.418
Intermittent buggines with user mode emulation of x86-64 on aarch64
QEMU Version: 5.0.0
./configure --target-list=x86_64-linux-user --enable-user --prefix=/opt/qemu --static
Testing using node_exporter from pmm-client-1.17.4-1.el8.x86_64.rpm
aarch64 system is running CentOS 8 with a mainline 5.4.52 kernel built for 4KB memory pages.
On aarch64 machine, invoke:
./qemu-x86_64-static /usr/local/percona/pmm-client/node_exporter.x86_64 -web.listen-address=192.168.0.10:42000 -web.auth-file=/usr/local/percona/pmm-client/pmm.yml -web.ssl-key-file=/usr/local/percona/pmm-client/server.key -web.ssl-cert-file=/usr/local/percona/pmm-client/server.crt -collectors.enabled=diskstats,filefd,filesystem,loadavg,meminfo,netdev,netstat,stat,time,uname,vmstat,meminfo_numa,textfile
Most of the time it will outright segfault within a few seconds, seemingly when the prometheus server polls for data.
But, about once every 10 times, it will not sefault and will continue working just fine forever.
The dynamically linked version of qemu (built without --static) always works without segfaulting, but it just doesn't work, the prometheus server gets no data from it. Again, once in a while it will work, but even when it doesn't work it won't segfault.
This vaguely feels like a memory alignment issue somewhere, but my debug-fu is not quite strong enough to attack the problem.
As another interesting data point - with dynamically linked qemu-x86_64, when it doesn't work, the process is consuming about 140% of CPU. On a successful run, the process is consuming about 30% of CPU.
The QEMU project is currently moving its bug tracking to another system.
For this we need to know which bugs are still valid and which could be
closed already. Thus we are setting the bug state to "Incomplete" now.
If the bug has already been fixed in the latest upstream version of QEMU,
then please close this ticket as "Fix released".
If it is not fixed yet and you think that this bug report here is still
valid, then you have two options:
1) If you already have an account on gitlab.com, please open a new ticket
for this problem in our new tracker here:
https://gitlab.com/qemu-project/qemu/-/issues
and then close this ticket here on Launchpad (or let it expire auto-
matically after 60 days). Please mention the URL of this bug ticket on
Launchpad in the new ticket on GitLab.
2) If you don't have an account on gitlab.com and don't intend to get
one, but still would like to keep this ticket opened, then please switch
the state back to "New" within the next 60 days (otherwise it will get
closed as "Expired"). We will then eventually migrate the ticket auto-
matically to the new system (but you won't be the reporter of the bug
in the new system and thus won't get notified on changes anymore).
Thank you and sorry for the inconvenience.
[Expired for QEMU because there has been no activity for 60 days.]
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