@@ -95,6 +95,7 @@ static int xen_syscore_suspend(void)
gnttab_suspend();
xen_manage_runstate_time(-1);
+ xen_save_sched_clock_offset();
xrfp.domid = DOMID_SELF;
xrfp.gpfn = __pa(HYPERVISOR_shared_info) >> PAGE_SHIFT;
ret = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrfp);
@@ -110,6 +111,12 @@ static void xen_syscore_resume(void)
xen_hvm_map_shared_info();
pvclock_resume();
+ /*
+ * Restore xen_sched_clock_offset during resume to maintain
+ * monotonic clock value
+ */
+ xen_restore_sched_clock_offset();
+
xen_manage_runstate_time(0);
gnttab_resume();
}
Save/restore xen_sched_clock_offset in syscore suspend/resume during PM hibernation. Commit '867cefb4cb1012: ("xen: Fix x86 sched_clock() interface for xen")' fixes xen guest time handling during migration. A similar issue is seen during PM hibernation when system runs CPU intensive workload. Post resume pvclock resets the value to 0 however, xen sched_clock_offset is never updated. System instability is seen during resume from hibernation when system is under heavy CPU load. Since xen_sched_clock_offset is not updated, system does not see the monotonic clock value and the scheduler would then think that heavy CPU hog tasks need more time in CPU, causing the system to freeze Signed-off-by: Anchal Agarwal <anchalag@amazon.com> --- arch/x86/xen/suspend.c | 7 +++++++ 1 file changed, 7 insertions(+)