• Juergen Gross's avatar
    xen: Fix x86 sched_clock() interface for xen · 867cefb4
    Juergen Gross authored
    Commit f94c8d11 ("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: f94c8d11 ("sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface")
    Cc: <stable@vger.kernel.org> # 4.11
    Reported-by: default avatarHans van Kranenburg <hans.van.kranenburg@mendix.com>
    Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
    Tested-by: default avatarHans van Kranenburg <hans.van.kranenburg@mendix.com>
    Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
    867cefb4
time.c 14.5 KB