Re: Recent upgrade of 4.13 -> 4.14 issue

[Frédéric Pierret <frederic.pierret@xxxxxxxxxxxx>]

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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