Hi,
On 1/14/19 1:44 PM, Juergen Gross wrote:
Commit f94c8d11699759 ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface") broke Xen guest time handling across migration:
[ 187.249951] Freezing user space processes ... (elapsed 0.001 seconds) done. [ 187.251137] OOM killer disabled. [ 187.251137] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [ 187.252299] suspending xenstore... [ 187.266987] xen:grant_table: Grant tables using version 1 layout [18446743811.706476] OOM killer enabled. [18446743811.706478] Restarting tasks ... done. [18446743811.720505] Setting capacity to 16777216
Fix that by setting xen_sched_clock_offset at resume time to ensure a monotonic clock value.
[...]
With v3 of the patch, I see the time jump in one log line happen, but only when using PVH.
[ 49.486453] Freezing user space processes ... (elapsed 0.002 seconds) done. [ 49.488743] OOM killer disabled. [ 49.488764] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done. [ 49.491117] suspending xenstore... [2000731.388722] xen:events: Xen HVM callback vector for event delivery is enabled [ 49.491750] xen:grant_table: Grant tables using version 1 layout [ 49.810722] OOM killer enabled. [ 49.810744] Restarting tasks ... done. [ 49.856263] Setting capacity to 6291456 [ 50.006002] Setting capacity to 10485760
If I start as PV, it never seems to happen.
Up to you to decide how important this is. :)
FYI this is with v3 on top of the Debian stretch-backports 4.19 kernel, which I'm starting to use now to reboot things with.
-# uname -a Linux appnode-kylie 4.19.0-0.bpo.1-cloud-amd64 #1 SMP Debian 4.19.12-1~bpo9+1+mendix1 (2019-01-15) x86_64 GNU/Linux
https://salsa.debian.org/knorrie-guest/linux/commits/mendix/stretch-backport...
Hans