| Message ID | 20200702182251.GA3606@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Fix PM hibernation in Xen guests | expand |
diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index e8c924e93fc5..10cd14326472 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -94,10 +94,9 @@ static int xen_syscore_suspend(void) int ret; gnttab_suspend(); - + xen_manage_runstate_time(-1); xrfp.domid = DOMID_SELF; xrfp.gpfn = __pa(HYPERVISOR_shared_info) >> PAGE_SHIFT; - ret = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrfp); if (!ret) HYPERVISOR_shared_info = &xen_dummy_shared_info; @@ -111,7 +110,7 @@ static void xen_syscore_resume(void) xen_hvm_map_shared_info(); pvclock_resume(); - + xen_manage_runstate_time(0); gnttab_resume(); }
Save/restore steal times in syscore suspend/resume during PM hibernation. Commit '5e25f5db6abb9: ("xen/time: do not decrease steal time after live migration on xen")' fixes xen guest steal time handling during migration. A similar issue is seen during PM hibernation. Currently, steal time accounting code in scheduler expects steal clock callback to provide monotonically increasing value. If the accounting code receives a smaller value than previous one, it uses a negative value to calculate steal time and results in incorrectly updated idle and steal time accounting. This breaks userspace tools which read /proc/stat. top - 08:05:35 up 2:12, 3 users, load average: 0.00, 0.07, 0.23 Tasks: 80 total, 1 running, 79 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,30100.0%id, 0.0%wa, 0.0%hi, 0.0%si,-1253874204672.0%st This can actually happen when a Xen PVHVM guest gets restored from hibernation, because such a restored guest is just a fresh domain from Xen perspective and the time information in runstate info starts over from scratch. Changelog: v1->v2: Removed patches that introduced new function calls for saving/restoring sched clock offset and using existing ones that are used during LM Signed-off-by: Anchal Agarwal <anchalag@amazon.com> --- arch/x86/xen/suspend.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)