Re: Recent upgrade of 4.13 -> 4.14 issue

[Frédéric Pierret]

Le 11/3/20 à 3:15 PM, Dario Faggioli a écrit :

On Tue, 2020-11-03 at 14:23 +0100, Frédéric Pierret wrote:

Hi,

Hi,

Some new info :). Marek has sent me a patch (
https://gist.github.com/marmarek/810ae5c079d218928535514b08a07716) to
help in debugging this issue.

Ok, thanks for the update (and thanks Mark for putthing together the
patch).

With default credit2 as scheduler, here are some log from two
successive crashes:
- https://gist.github.com/fepitre/76a1e154249c7326c743d6a6d004a67b
- https://gist.github.com/fepitre/ab00091980cb8110fb3d349aecc3a644

Right, this is what you see when you poke at the debug keys, after a
freeze. It would be interesting to see if there is any trace of the
debug output added in the patch _before_ the crash... But I appreciate
that it's not really easy to achieve this.

I'll try to find this info in the next days.

Also, I've been testing "dom0=pvh" option and the system remains
stable since more than 24h. At least, I've not experimented any
freeze since I'm using this option.

PVH and what scheduler?

PVH and Credit2.

I think it's quite clear that this is not a Credit2 bug, as it shows on
Credit1 as well, but AFAIUI, with Credit2 it shows up more often?

Now we also have a (weak?) dependency on the type of dom0?

It seems so.

What's the configuration that is currently working?
Credit2 +PVH ?
Credit1 + PVH ?
Whatever + PVH ?

The only differences between Credit1 and 2 was that Credit2 was generating freezes faster 
than Credit1. Here is the output of `xl info` of the current "stable" running 
config:

"""
[admin@dom0 ~]$ xl info
host                   : dom0
release                : 5.4.72-2.qubes.x86_64
version                : #1 SMP Sun Oct 18 16:17:06 CEST 2020
machine                : x86_64
nr_cpus                : 16
max_cpu_id             : 63
nr_nodes               : 2
cores_per_socket       : 8
threads_per_core       : 1
cpu_mhz                : 2593.766
hw_caps                : 
bfebfbff:17bee3ff:2c100800:00000001:00000001:00000000:00000000:00000100
virt_caps              : pv hvm hvm_directio pv_directio hap
total_memory           : 163805
free_memory            : 11077
sharing_freed_memory   : 0
sharing_used_memory    : 0
outstanding_claims     : 0
free_cpus              : 0
xen_major              : 4
xen_minor              : 14
xen_extra              : .0
xen_version            : 4.14.0
xen_caps               : xen-3.0-x86_64 hvm-3.0-x86_32 hvm-3.0-x86_32p 
hvm-3.0-x86_64
xen_scheduler          : credit2
xen_pagesize           : 4096
platform_params        : virt_start=0xffff800000000000
xen_changeset          :
xen_commandline        : placeholder console=com2 dom0_mem=min:1024M 
dom0_mem=max:8192M iommu=no-igfx ucode=scan smt=off gnttab_max_frames=2048 
gnttab_max_maptrack_frames=4096 loglvl=all guest_loglvl=all dom0=pvh
cc_compiler            : gcc (GCC) 10.2.1 20201016 (Red Hat 10.2.1-6)
cc_compile_by          : user
cc_compile_domain      : [unknown]
cc_compile_date        : Sat Oct 31 16:02:25 UTC 2020
build_id               : 0bbdc8aa6f34a2b27c3ac9842741bc022269f9ee
xend_config_format     : 4
"""

Regards

Regards,
Frédéric

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