xen: Fix x86 sched_clock() interface for xen

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commit 867cefb4cb upstream.

Commit f94c8d1169 ("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.

[boris: replaced pr_info() with pr_info_once() in xen_callback_vector()
 to avoid printing with incorrect timestamp during resume (as we
 haven't re-adjusted the clock yet)]

Fixes: f94c8d1169 ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface")
Cc: <stable@vger.kernel.org> # 4.11
Reported-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Juergen Gross 2019-01-14 13:44:13 +01:00 • committed by Greg Kroah-Hartman

parent b7984d4617

commit d14816d532

2 changed files with 10 additions and 4 deletions

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12

arch/x86/xen/time.c

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2

drivers/xen/events/events_base.c

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