Re: boot hang on commit "PM / ACPI: Fix suspend/resume regressioncaused by cpuidle cleanup."
From: Deepthi Dharwar
Date: Fri Jun 22 2012 - 05:57:28 EST
Hi,
This is interesting .. suspend fix breaking boot on kvm.
We complied and booted fine with mainline kernels including 3.5-rc2 with
this fix on servers and laptops.
So wondering how different is booting on machines Vs
from kvm ?
Also, are you seeing smooth boot on kvm by reverting only this patch ?
Cheers
Deepthi
On 06/22/2012 01:05 PM, wfg@xxxxxxxxxxxxxxx wrote:
> Hi Deepthi,
>
> It seems that commit de08622 triggers a boot hang in my kvm boot test.
>
> kvm -cpu kvm64 -enable-kvm \
> -kernel ./gpxelinux.lkrn \
> -initrd ./kvm.gpxe \
> -m 384M \
> -net nic,vlan=0,macaddr=00:00:00:00:00:00,model=e1000 \
> -net user,vlan=0,hostfwd=tcp::$port-:22 \
> -boot order=nc \
> -no-reboot \
> -watchdog i6300esb \
> $(qemu_drives) \
> -pidfile $pidfile \
> -serial file:$dmesg
>
> tree: git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
> head: de08622731417ba429fc470ab8f2d7c260cb5c72
> commit: de08622731417ba429fc470ab8f2d7c260cb5c72 [9/9] PM / ACPI: Fix suspend/resume regression caused by cpuidle cleanup.
> config: x86_64-allyesdebian (attached as .config)
>
> x86_64-allyesdebian bbbbbbbbbB
> --
> 8: b 0eb8c06 2012-06-19 22:23:37 +0200 PM / Sleep: Separate printing suspend times from initcall_debug
> 9: B de08622 boot hang after [ 81.370898] usbcore: registered new interface driver dw2102
>
> legend: [b] boot fine [B] boot error
>
> commit de08622731417ba429fc470ab8f2d7c260cb5c72
> Author: Deepthi Dharwar <deepthi@xxxxxxxxxxxxxxxxxx>
> Date: Wed Jun 13 16:28:17 2012 +0530
>
> PM / ACPI: Fix suspend/resume regression caused by cpuidle cleanup.
>
> Commit e978aa7d7d57d04eb5f88a7507c4fb98577def77 ( cpuidle: Move
> dev->last_residency update to driver enter routine; remove dev->last_state)
> was breaking suspend on laptops, as reported in the below link
> - https://lkml.org/lkml/2011/11/11/164
>
> This was fixed in commit 3439a8da16bcad6b0982ece938c9f8299bb53584
> (ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend regression)
> by removing acpi_idle_suspend flag.
> - https://lkml.org/lkml/2011/11/14/74
>
> But this fix did not work on all systems
> as Suspend/resume regression was reported on Lenovo S10-3
> recently by Dave.
> - https://lkml.org/lkml/2012/5/27/115
> It looked like with commit e978aa7d broke suspend and
> with commit 3439a8da resume was not working with acpi_idle driver.
>
> This patch fixes the regression that caused this issue
> in the first place. acpi_idle_suspend flag is essential on
> some x86 systems to prevent the cpus from going to deeper C-states
> when suspend is triggered ( commit b04e7bdb984 )
> So reverting the commit 3439a8da is essential.
>
> By default, irqs are disabled in cpu_idle arch specific call
> and re-enabled in idle state return path . As the acpi_idle_suspend
> flag was being set during suspend, which prevented the cpus
> going to deeper idle states, it is essential to
> enabling the irqs in its return path too.
>
> To address the suspend issue,
> we were not re-enabling the interrupts while returning from
> acpi_idle_enter_bm() routine if acpi_idle_suspend flag is set.
> and this was causing suspend failure.
>
> In addition to the above fix, a sanity check has also been added
> in x86 arch specific cpu_idle call to ensure that the idle call
> always returns with IRQs enabled.
>
> Signed-off-by: Deepthi Dharwar <deepthi@xxxxxxxxxxxxxxxxxx>
> Reported-and-Tested-by: Dav Hansen <dave@xxxxxxxxxxxxxxxxxx>
> Tested-by: Preeti Murthy <preeti@xxxxxxxxxxxxxxxxxx>
> Reviewed-by: Srivatsa S Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
>
> diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
> index 735279e..8ab76ad 100644
> --- a/arch/x86/kernel/process.c
> +++ b/arch/x86/kernel/process.c
> @@ -460,6 +460,12 @@ void cpu_idle(void)
> pm_idle();
>
> rcu_idle_exit();
> +
> + /*
> + * Sanity check to ensure that idle call returns
> + * with IRQs enabled
> + */
> + WARN_ON(irqs_disabled());
> start_critical_timings();
>
> /* In many cases the interrupt that ended idle
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index f3decb3..c2ffd84 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -224,6 +224,7 @@ static void lapic_timer_state_broadcast(struct acpi_processor *pr,
> /*
> * Suspend / resume control
> */
> +static int acpi_idle_suspend;
> static u32 saved_bm_rld;
>
> static void acpi_idle_bm_rld_save(void)
> @@ -242,13 +243,21 @@ static void acpi_idle_bm_rld_restore(void)
>
> int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
> {
> + if (acpi_idle_suspend == 1)
> + return 0;
> +
> acpi_idle_bm_rld_save();
> + acpi_idle_suspend = 1;
> return 0;
> }
>
> int acpi_processor_resume(struct acpi_device * device)
> {
> + if (acpi_idle_suspend == 0)
> + return 0;
> +
> acpi_idle_bm_rld_restore();
> + acpi_idle_suspend = 0;
> return 0;
> }
>
> @@ -754,6 +763,12 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev,
>
> local_irq_disable();
>
> + if (acpi_idle_suspend) {
> + local_irq_enable();
> + cpu_relax();
> + return -EINVAL;
> + }
> +
> lapic_timer_state_broadcast(pr, cx, 1);
> kt1 = ktime_get_real();
> acpi_idle_do_entry(cx);
> @@ -823,6 +838,12 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev,
>
> local_irq_disable();
>
> + if (acpi_idle_suspend) {
> + local_irq_enable();
> + cpu_relax();
> + return -EINVAL;
> + }
> +
> if (cx->entry_method != ACPI_CSTATE_FFH) {
> current_thread_info()->status &= ~TS_POLLING;
> /*
> @@ -901,6 +922,13 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev,
> if (unlikely(!pr))
> return -EINVAL;
>
> + if (acpi_idle_suspend) {
> + if (irqs_disabled())
> + local_irq_enable();
> + cpu_relax();
> + return -EINVAL;
> + }
> +
> if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
> if (drv->safe_state_index >= 0) {
> return drv->states[drv->safe_state_index].enter(dev,
--
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