On (Tue) 07 Feb 2012 [19:05:42], Marcelo Tosatti wrote: > > Upon resume from hibernation, CPU 0's hvclock area contains the old > values for system_time and tsc_timestamp. It is necessary for the > hypervisor to update these values with uptodate ones before the CPU uses > them. > > Abstract TSC's save/restore sched_clock_state functions and use > restore_state to write to KVM_SYSTEM_TIME MSR, forcing an update. > > Fixes suspend-to-disk with kvmclock. There are stalls after resume, see trace below. ./x86_64-softmmu/qemu-system-x86_64 -kernel ~/src/linux/arch/x86/boot/bzImage -append 'root=/dev/vda1 console=tty0 console=ttyS0 no_console_suspend' -drive file=/guests/f14-suspend.qcow2,if=none,id=dr0 -device virtio-blk-pci,drive=dr0 -net nic,model=virtio -net user -serial stdio -enable-kvm -m 512 -cpu host -smp 4 <The following is on resume:> Disabling non-boot CPUs ... CPU 1 is now offline CPU 2 is now offline CPU 3 is now offline lockdep: fixing up alternatives. kvm-clock: cpu 0, msr 0:1f1d19c1, primary cpu clock, resume PM: Restoring platform NVS memory Enabling non-boot CPUs ... lockdep: fixing up alternatives. Booting Node 0 Processor 1 APIC 0x1 Calibrating delay loop (skipped) already calibrated this CPU INFO: rcu_sched detected stalls on CPUs/tasks: { 1} (detected by 0, t=314192 jiffies) Pid: 662, comm: bash Not tainted 3.3.0-rc2+ #293 Call Trace: <IRQ> [<ffffffff8108b6c9>] __rcu_pending+0x268/0x3c5 [<ffffffff8108bef5>] rcu_check_callbacks+0xab/0x108 [<ffffffff81031208>] update_process_times+0x3f/0x75 [<ffffffff810649b5>] tick_sched_timer+0x6d/0x8c [<ffffffff81042e68>] __run_hrtimer+0xc9/0x15c [<ffffffff81064948>] ? tick_nohz_handler+0xd5/0xd5 [<ffffffff8104359b>] hrtimer_interrupt+0xea/0x1b4 [<ffffffff81316192>] smp_apic_timer_interrupt+0x76/0x89 [<ffffffff81315833>] apic_timer_interrupt+0x73/0x80 <EOI> [<ffffffff8130b9ec>] ? arch_local_irq_restore+0x6/0xd [<ffffffff8130840c>] native_cpu_up+0x108/0x127 [<ffffffff81308f2b>] _cpu_up+0x92/0xfc [<ffffffff812facf7>] enable_nonboot_cpus+0x4d/0xb2 [<ffffffff81059836>] hibernation_snapshot+0x1f3/0x2a0 [<ffffffff81044406>] ? cleanup_srcu_struct+0x52/0x58 [<ffffffff81059e6d>] hibernate+0x97/0x196 [<ffffffff81057eb0>] state_store+0x5c/0x106 [<ffffffff811af49b>] kobj_attr_store+0x17/0x19 [<ffffffff811368fa>] sysfs_write_file+0x10e/0x14a [<ffffffff810eb5f6>] vfs_write+0xab/0xd2 [<ffffffff810ec955>] ? fget_light+0x3a/0xa1 [<ffffffff810eb7ad>] sys_write+0x4d/0x74 [<ffffffff81314ce9>] system_call_fastpath+0x16/0x1b INFO: rcu_preempt detected stalls on CPUs/tasks: { 1} (detected by 0, t=314193 jiffies) Pid: 662, comm: bash Not tainted 3.3.0-rc2+ #293 Call Trace: <IRQ> [<ffffffff8108b6c9>] __rcu_pending+0x268/0x3c5 [<ffffffff8108bf33>] rcu_check_callbacks+0xe9/0x108 [<ffffffff81031208>] update_process_times+0x3f/0x75 [<ffffffff810649b5>] tick_sched_timer+0x6d/0x8c [<ffffffff81042e68>] __run_hrtimer+0xc9/0x15c [<ffffffff81064948>] ? tick_nohz_handler+0xd5/0xd5 [<ffffffff8104359b>] hrtimer_interrupt+0xea/0x1b4 [<ffffffff81316192>] smp_apic_timer_interrupt+0x76/0x89 [<ffffffff81315833>] apic_timer_interrupt+0x73/0x80 <EOI> [<ffffffff8130b9ec>] ? arch_local_irq_restore+0x6/0xd [<ffffffff8130840c>] native_cpu_up+0x108/0x127 [<ffffffff81308f2b>] _cpu_up+0x92/0xfc [<ffffffff812facf7>] enable_nonboot_cpus+0x4d/0xb2 [<ffffffff81059836>] hibernation_snapshot+0x1f3/0x2a0 [<ffffffff81044406>] ? cleanup_srcu_struct+0x52/0x58 [<ffffffff81059e6d>] hibernate+0x97/0x196 [<ffffffff81057eb0>] state_store+0x5c/0x106 [<ffffffff811af49b>] kobj_attr_store+0x17/0x19 [<ffffffff811368fa>] sysfs_write_file+0x10e/0x14a [<ffffffff810eb5f6>] vfs_write+0xab/0xd2 [<ffffffff810ec955>] ? fget_light+0x3a/0xa1 [<ffffffff810eb7ad>] sys_write+0x4d/0x74 [<ffffffff81314ce9>] system_call_fastpath+0x16/0x1b INFO: rcu_sched detected stalls on CPUs/tasks: { 1} (detected by 0, t=1713579840232 jiffies) Pid: 662, comm: bash Not tainted 3.3.0-rc2+ #293 Call Trace: <IRQ> [<ffffffff8108b6c9>] __rcu_pending+0x268/0x3c5 [<ffffffff8108bef5>] rcu_check_callbacks+0xab/0x108 [<ffffffff81031208>] update_process_times+0x3f/0x75 [<ffffffff810649b5>] tick_sched_timer+0x6d/0x8c [<ffffffff81042e68>] __run_hrtimer+0xc9/0x15c [<ffffffff81064948>] ? tick_nohz_handler+0xd5/0xd5 [<ffffffff8104359b>] hrtimer_interrupt+0xea/0x1b4 [<ffffffff81316192>] smp_apic_timer_interrupt+0x76/0x89 [<ffffffff81315833>] apic_timer_interrupt+0x73/0x80 <EOI> [<ffffffff8130b9ec>] ? arch_local_irq_restore+0x6/0xd [<ffffffff8130840c>] native_cpu_up+0x108/0x127 [<ffffffff81308f2b>] _cpu_up+0x92/0xfc [<ffffffff812facf7>] enable_nonboot_cpus+0x4d/0xb2 [<ffffffff81059836>] hibernation_snapshot+0x1f3/0x2a0 [<ffffffff81044406>] ? cleanup_srcu_struct+0x52/0x58 [<ffffffff81059e6d>] hibernate+0x97/0x196 [<ffffffff81057eb0>] state_store+0x5c/0x106 [<ffffffff811af49b>] kobj_attr_store+0x17/0x19 [<ffffffff811368fa>] sysfs_write_file+0x10e/0x14a [<ffffffff810eb5f6>] vfs_write+0xab/0xd2 [<ffffffff810ec955>] ? fget_light+0x3a/0xa1 [<ffffffff810eb7ad>] sys_write+0x4d/0x74 [<ffffffff81314ce9>] system_call_fastpath+0x16/0x1b INFO: rcu_preempt detected stalls on CPUs/tasks: { 1} (detected by 0, t=1713579840233 jiffies) Pid: 662, comm: bash Not tainted 3.3.0-rc2+ #293 Call Trace: <IRQ> [<ffffffff8108b6c9>] __rcu_pending+0x268/0x3c5 [<ffffffff8108bf33>] rcu_check_callbacks+0xe9/0x108 [<ffffffff81031208>] update_process_times+0x3f/0x75 [<ffffffff810649b5>] tick_sched_timer+0x6d/0x8c [<ffffffff81042e68>] __run_hrtimer+0xc9/0x15c [<ffffffff81064948>] ? tick_nohz_handler+0xd5/0xd5 [<ffffffff8104359b>] hrtimer_interrupt+0xea/0x1b4 [<ffffffff81316192>] smp_apic_timer_interrupt+0x76/0x89 [<ffffffff81315833>] apic_timer_interrupt+0x73/0x80 <EOI> [<ffffffff8130b9ec>] ? arch_local_irq_restore+0x6/0xd [<ffffffff8130840c>] native_cpu_up+0x108/0x127 [<ffffffff81308f2b>] _cpu_up+0x92/0xfc [<ffffffff812facf7>] enable_nonboot_cpus+0x4d/0xb2 [<ffffffff81059836>] hibernation_snapshot+0x1f3/0x2a0 [<ffffffff81044406>] ? cleanup_srcu_struct+0x52/0x58 [<ffffffff81059e6d>] hibernate+0x97/0x196 [<ffffffff81057eb0>] state_store+0x5c/0x106 [<ffffffff811af49b>] kobj_attr_store+0x17/0x19 [<ffffffff811368fa>] sysfs_write_file+0x10e/0x14a [<ffffffff810eb5f6>] vfs_write+0xab/0xd2 [<ffffffff810ec955>] ? fget_light+0x3a/0xa1 [<ffffffff810eb7ad>] sys_write+0x4d/0x74 [<ffffffff81314ce9>] system_call_fastpath+0x16/0x1b Amit -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html