Actually implementing this fix causes a linux boot to crash. So there may be something more to this. I will investigate more.
[ 892.294463] BUG: soft lockup - CPU#0 stuck for 347s! [swapper/0:1] [ 892.490416] Modules linked in: [ 892.635725] [ 892.790816] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.16.0-6-armmp-lpae #1 Debian 3.16.56-1+deb8u1 [ 893.098786] task: ee059640 ti: ee05a000 task.ti: ee05a000 [ 893.322395] PC is at vprintk_emit+0x2c8/0x650 [ 893.525852] LR is at console_unlock+0x234/0x4dc [ 893.749395] pc : [<c00bdd18>] lr : [<c00bd7a8>] psr: 60000153 [ 893.749395] sp : ee05bdc8 ip : ee05bd70 fp : ee05be2c [ 894.117789] r10: 00000001 r9 : 00000000 r8 : 00000006 [ 894.329454] r7 : 00000000 r6 : 00000028 r5 : c0a3dd98 r4 : c0a3dd98 [ 894.571266] r3 : c09b44cc r2 : 60000153 r1 : 60000153 r0 : c0a3dd98 [ 894.807621] Flags: nZCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment kernel [ 895.089213] Control: 30c7387d Table: 40003000 DAC: fffffffd [ 895.329468] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.16.0-6-armmp-lpae #1 Debian 3.16.56-1+deb8u1 [ 895.720505] [<c002cf60>] (unwind_backtrace) from [<c002764c>] (show_stack+0x20/0x24) [ 896.065798] [<c002764c>] (show_stack) from [<c05ed770>] (dump_stack+0x9c/0xb0) [ 896.393691] [<c05ed770>] (dump_stack) from [<c0024370>] (show_regs+0x30/0x34) [ 896.713637] [<c0024370>] (show_regs) from [<c0103084>] (watchdog_timer_fn+0x18c/0x1e4) [ 897.062977] [<c0103084>] (watchdog_timer_fn) from [<c008d9c0>] (__run_hrtimer+0x88/0x2a8) [ 897.412317] [<c008d9c0>] (__run_hrtimer) from [<c008ecf0>] (hrtimer_run_queues+0xc0/0x1a4) [ 897.785790] [<c008ecf0>] (hrtimer_run_queues) from [<c0076ef0>] (update_process_times+0x3c/0x70) [ 898.169815] [<c0076ef0>] (update_process_times) from [<c00d5ed4>] (tick_periodic+0x4c/0xcc) [ 898.532622] [<c00d5ed4>] (tick_periodic) from [<c00d61b0>] (tick_handle_periodic+0x94/0x98) [ 898.895806] [<c00d61b0>] (tick_handle_periodic) from [<c04ad8fc>] (arch_timer_handler_virt+0x38/0x40) [ 899.292479] [<c04ad8fc>] (arch_timer_handler_virt) from [<c00c3b48>] (handle_percpu_devid_irq+0x80/0x194) [ 899.702210] [<c00c3b48>] (handle_percpu_devid_irq) from [<c00bf738>] (generic_handle_irq+0x3c/0x4c) [ 900.082647] [<c00bf738>] (generic_handle_irq) from [<c0023ba4>] (handle_IRQ+0x50/0xa0) [ 900.427431] [<c0023ba4>] (handle_IRQ) from [<c0008948>] (gic_handle_irq+0x3c/0x70) [ 900.767678] [<c0008948>] (gic_handle_irq) from [<c05f4180>] (__irq_svc+0x40/0x54) [ 901.037948] Exception stack(0xee05bd80 to 0xee05bdc8) [ 901.317607] bd80: c0a3dd98 60000153 60000153 c09b44cc c0a3dd98 c0a3dd98 00000028 00000000 [ 901.677252] bda0: 00000006 00000000 00000001 ee05be2c ee05bd70 ee05bdc8 c00bd7a8 c00bdd18 [ 901.970690] bdc0: 60000153 ffffffff [ 902.218760] [<c05f4180>] (__irq_svc) from [<c00bdd18>] (vprintk_emit+0x2c8/0x650) [ 902.571360] [<c00bdd18>] (vprintk_emit) from [<c05eaeb8>] (printk+0x44/0x4c) [ 902.916079] [<c05eaeb8>] (printk) from [<c00d14c0>] (__clocksource_select+0x12c/0x170) [ 903.290503] [<c00d14c0>] (__clocksource_select) from [<c08da7d4>] (clocksource_done_booting+0x38/0x4c) [ 903.671545] [<c08da7d4>] (clocksource_done_booting) from [<c0008d14>] (do_one_initcall+0xf0/0x234) [ 904.050606] [<c0008d14>] (do_one_initcall) from [<c08b2ec0>] (kernel_init_freeable+0x1c8/0x268) [ 904.433926] [<c08b2ec0>] (kernel_init_freeable) from [<c05e82ac>] (kernel_init+0x1c/0x100) [ 904.797782] [<c05e82ac>] (kernel_init) from [<c0023280>] (ret_from_fork+0x14/0x20) ** Changed in: ubuntu Status: New => Incomplete -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1783422 Title: qemu_clock_get_ns does not take into account icount_time_shift Status in QEMU: Incomplete Bug description: Hello, If you check the qemu/util/qemu-timer.c you will find the following function: 597: int64_t qemu_clock_get_ns(QEMUClockType type) 598: { .... 602: switch (type) { .... 606: case QEMU_CLOCK_VIRTUAL: 607: if (use_icount) { 608: return cpu_get_icount(); Now on line 606, in case we requested QEMU_CLOCK_VIRTUAL, and we are using icount, the value of cpu_get_icount(); will be returned. However if I understand correctly, in order to convert icount to ns, you must use take into account the icount shift -- as defined in the documentation: "The virtual cpu will execute one instruction every 2^N ns of virtual time.". Therefor, the correct value to return would be cpu_icount_to_ns(cpu_get_icount()), where cpu_icount_to_ns is defined in cpus.c: 296: int64_t cpu_icount_to_ns(int64_t icount) 297: { 298: return icount << icount_time_shift; 299: } Best Regards, Humberto "SilverOne" Carvalho To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1783422/+subscriptions