| Message ID | 20200403140345.3828-1-cai@lca.pw (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | [v3] x86/acpi: fix a deadlock with cpu hotplug | expand |
On Fri, Apr 3, 2020 at 4:04 PM Qian Cai <cai@lca.pw> wrote: > > Similar to the commit 0266d81e9bf5 ("acpi/processor: Prevent cpu hotplug > deadlock") except this is for acpi_processor_ffh_cstate_probe(): > > "The problem is that the work is scheduled on the current CPU from the > hotplug thread associated with that CPU. > > It's not required to invoke these functions via the workqueue because > the hotplug thread runs on the target CPU already. > > Check whether current is a per cpu thread pinned on the target CPU and > invoke the function directly to avoid the workqueue." > > WARNING: possible circular locking dependency detected > ------------------------------------------------------ > cpuhp/1/15 is trying to acquire lock: > ffffc90003447a28 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: __flush_work+0x4c6/0x630 > > but task is already holding lock: > ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20 > > which lock already depends on the new lock. > > the existing dependency chain (in reverse order) is: > > -> #1 (cpu_hotplug_lock){++++}-{0:0}: > cpus_read_lock+0x3e/0xc0 > irq_calc_affinity_vectors+0x5f/0x91 > __pci_enable_msix_range+0x10f/0x9a0 > pci_alloc_irq_vectors_affinity+0x13e/0x1f0 > pci_alloc_irq_vectors_affinity at drivers/pci/msi.c:1208 > pqi_ctrl_init+0x72f/0x1618 [smartpqi] > pqi_pci_probe.cold.63+0x882/0x892 [smartpqi] > local_pci_probe+0x7a/0xc0 > work_for_cpu_fn+0x2e/0x50 > process_one_work+0x57e/0xb90 > worker_thread+0x363/0x5b0 > kthread+0x1f4/0x220 > ret_from_fork+0x27/0x50 > > -> #0 ((work_completion)(&wfc.work)){+.+.}-{0:0}: > __lock_acquire+0x2244/0x32a0 > lock_acquire+0x1a2/0x680 > __flush_work+0x4e6/0x630 > work_on_cpu+0x114/0x160 > acpi_processor_ffh_cstate_probe+0x129/0x250 > acpi_processor_evaluate_cst+0x4c8/0x580 > acpi_processor_get_power_info+0x86/0x740 > acpi_processor_hotplug+0xc3/0x140 > acpi_soft_cpu_online+0x102/0x1d0 > cpuhp_invoke_callback+0x197/0x1120 > cpuhp_thread_fun+0x252/0x2f0 > smpboot_thread_fn+0x255/0x440 > kthread+0x1f4/0x220 > ret_from_fork+0x27/0x50 > > other info that might help us debug this: > > Chain exists of: > (work_completion)(&wfc.work) --> cpuhp_state-up --> cpuidle_lock > > Possible unsafe locking scenario: > > CPU0 CPU1 > ---- ---- > lock(cpuidle_lock); > lock(cpuhp_state-up); > lock(cpuidle_lock); > lock((work_completion)(&wfc.work)); > > *** DEADLOCK *** > > 3 locks held by cpuhp/1/15: > #0: ffffffffaf51ab10 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0 > #1: ffffffffaf51ad40 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0 > #2: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20 > > Call Trace: > dump_stack+0xa0/0xea > print_circular_bug.cold.52+0x147/0x14c > check_noncircular+0x295/0x2d0 > __lock_acquire+0x2244/0x32a0 > lock_acquire+0x1a2/0x680 > __flush_work+0x4e6/0x630 > work_on_cpu+0x114/0x160 > acpi_processor_ffh_cstate_probe+0x129/0x250 > acpi_processor_evaluate_cst+0x4c8/0x580 > acpi_processor_get_power_info+0x86/0x740 > acpi_processor_hotplug+0xc3/0x140 > acpi_soft_cpu_online+0x102/0x1d0 > cpuhp_invoke_callback+0x197/0x1120 > cpuhp_thread_fun+0x252/0x2f0 > smpboot_thread_fn+0x255/0x440 > kthread+0x1f4/0x220 > ret_from_fork+0x27/0x50 > > Signed-off-by: Qian Cai <cai@lca.pw> I can take this one unless there are objections or concerns. > --- > > v3: > Remove #ifdef since cstate.o should rather depend on ACPI_PROCESSOR_IDLE > per Rafael. > > v2: > Make call_on_cpu() a static inline function to avoid a compilation > error when ACPI_PROCESSOR=m thanks to lkp@intel.com. > > arch/x86/kernel/acpi/cstate.c | 3 ++- > drivers/acpi/processor_throttling.c | 7 ------- > include/acpi/processor.h | 8 ++++++++ > 3 files changed, 10 insertions(+), 8 deletions(-) > > diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c > index caf2edccbad2..49ae4e1ac9cd 100644 > --- a/arch/x86/kernel/acpi/cstate.c > +++ b/arch/x86/kernel/acpi/cstate.c > @@ -161,7 +161,8 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu, > > /* Make sure we are running on right CPU */ > > - retval = work_on_cpu(cpu, acpi_processor_ffh_cstate_probe_cpu, cx); > + retval = call_on_cpu(cpu, acpi_processor_ffh_cstate_probe_cpu, cx, > + false); > if (retval == 0) { > /* Use the hint in CST */ > percpu_entry->states[cx->index].eax = cx->address; > diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c > index 532a1ae3595a..a0bd56ece3ff 100644 > --- a/drivers/acpi/processor_throttling.c > +++ b/drivers/acpi/processor_throttling.c > @@ -897,13 +897,6 @@ static long __acpi_processor_get_throttling(void *data) > return pr->throttling.acpi_processor_get_throttling(pr); > } > > -static int call_on_cpu(int cpu, long (*fn)(void *), void *arg, bool direct) > -{ > - if (direct || (is_percpu_thread() && cpu == smp_processor_id())) > - return fn(arg); > - return work_on_cpu(cpu, fn, arg); > -} > - > static int acpi_processor_get_throttling(struct acpi_processor *pr) > { > if (!pr) > diff --git a/include/acpi/processor.h b/include/acpi/processor.h > index 47805172e73d..683e124ad517 100644 > --- a/include/acpi/processor.h > +++ b/include/acpi/processor.h > @@ -297,6 +297,14 @@ static inline void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx > } > #endif > > +static inline int call_on_cpu(int cpu, long (*fn)(void *), void *arg, > + bool direct) > +{ > + if (direct || (is_percpu_thread() && cpu == smp_processor_id())) > + return fn(arg); > + return work_on_cpu(cpu, fn, arg); > +} > + > /* in processor_perflib.c */ > > #ifdef CONFIG_CPU_FREQ > -- > 2.21.0 (Apple Git-122.2) >
On Fri, Apr 03, 2020 at 05:45:10PM +0200, Rafael J. Wysocki wrote: > I can take this one unless there are objections or concerns. Please do - I did trigger that yesterday again. Tested-by: Borislav Petkov <bp@suse.de>
On Fri, Apr 3, 2020 at 6:53 PM Borislav Petkov <bp@alien8.de> wrote: > > On Fri, Apr 03, 2020 at 05:45:10PM +0200, Rafael J. Wysocki wrote: > > I can take this one unless there are objections or concerns. > > Please do - I did trigger that yesterday again. > > Tested-by: Borislav Petkov <bp@suse.de> OK, applied now, thanks!
diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c index caf2edccbad2..49ae4e1ac9cd 100644 --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -161,7 +161,8 @@ int acpi_processor_ffh_cstate_probe(unsigned int cpu, /* Make sure we are running on right CPU */ - retval = work_on_cpu(cpu, acpi_processor_ffh_cstate_probe_cpu, cx); + retval = call_on_cpu(cpu, acpi_processor_ffh_cstate_probe_cpu, cx, + false); if (retval == 0) { /* Use the hint in CST */ percpu_entry->states[cx->index].eax = cx->address; diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c index 532a1ae3595a..a0bd56ece3ff 100644 --- a/drivers/acpi/processor_throttling.c +++ b/drivers/acpi/processor_throttling.c @@ -897,13 +897,6 @@ static long __acpi_processor_get_throttling(void *data) return pr->throttling.acpi_processor_get_throttling(pr); } -static int call_on_cpu(int cpu, long (*fn)(void *), void *arg, bool direct) -{ - if (direct || (is_percpu_thread() && cpu == smp_processor_id())) - return fn(arg); - return work_on_cpu(cpu, fn, arg); -} - static int acpi_processor_get_throttling(struct acpi_processor *pr) { if (!pr) diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 47805172e73d..683e124ad517 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -297,6 +297,14 @@ static inline void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx } #endif +static inline int call_on_cpu(int cpu, long (*fn)(void *), void *arg, + bool direct) +{ + if (direct || (is_percpu_thread() && cpu == smp_processor_id())) + return fn(arg); + return work_on_cpu(cpu, fn, arg); +} + /* in processor_perflib.c */ #ifdef CONFIG_CPU_FREQ
Similar to the commit 0266d81e9bf5 ("acpi/processor: Prevent cpu hotplug deadlock") except this is for acpi_processor_ffh_cstate_probe(): "The problem is that the work is scheduled on the current CPU from the hotplug thread associated with that CPU. It's not required to invoke these functions via the workqueue because the hotplug thread runs on the target CPU already. Check whether current is a per cpu thread pinned on the target CPU and invoke the function directly to avoid the workqueue." WARNING: possible circular locking dependency detected ------------------------------------------------------ cpuhp/1/15 is trying to acquire lock: ffffc90003447a28 ((work_completion)(&wfc.work)){+.+.}-{0:0}, at: __flush_work+0x4c6/0x630 but task is already holding lock: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x3e/0xc0 irq_calc_affinity_vectors+0x5f/0x91 __pci_enable_msix_range+0x10f/0x9a0 pci_alloc_irq_vectors_affinity+0x13e/0x1f0 pci_alloc_irq_vectors_affinity at drivers/pci/msi.c:1208 pqi_ctrl_init+0x72f/0x1618 [smartpqi] pqi_pci_probe.cold.63+0x882/0x892 [smartpqi] local_pci_probe+0x7a/0xc0 work_for_cpu_fn+0x2e/0x50 process_one_work+0x57e/0xb90 worker_thread+0x363/0x5b0 kthread+0x1f4/0x220 ret_from_fork+0x27/0x50 -> #0 ((work_completion)(&wfc.work)){+.+.}-{0:0}: __lock_acquire+0x2244/0x32a0 lock_acquire+0x1a2/0x680 __flush_work+0x4e6/0x630 work_on_cpu+0x114/0x160 acpi_processor_ffh_cstate_probe+0x129/0x250 acpi_processor_evaluate_cst+0x4c8/0x580 acpi_processor_get_power_info+0x86/0x740 acpi_processor_hotplug+0xc3/0x140 acpi_soft_cpu_online+0x102/0x1d0 cpuhp_invoke_callback+0x197/0x1120 cpuhp_thread_fun+0x252/0x2f0 smpboot_thread_fn+0x255/0x440 kthread+0x1f4/0x220 ret_from_fork+0x27/0x50 other info that might help us debug this: Chain exists of: (work_completion)(&wfc.work) --> cpuhp_state-up --> cpuidle_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(cpuidle_lock); lock(cpuhp_state-up); lock(cpuidle_lock); lock((work_completion)(&wfc.work)); *** DEADLOCK *** 3 locks held by cpuhp/1/15: #0: ffffffffaf51ab10 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0 #1: ffffffffaf51ad40 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x69/0x2f0 #2: ffffffffafa1c0e8 (cpuidle_lock){+.+.}-{3:3}, at: cpuidle_pause_and_lock+0x17/0x20 Call Trace: dump_stack+0xa0/0xea print_circular_bug.cold.52+0x147/0x14c check_noncircular+0x295/0x2d0 __lock_acquire+0x2244/0x32a0 lock_acquire+0x1a2/0x680 __flush_work+0x4e6/0x630 work_on_cpu+0x114/0x160 acpi_processor_ffh_cstate_probe+0x129/0x250 acpi_processor_evaluate_cst+0x4c8/0x580 acpi_processor_get_power_info+0x86/0x740 acpi_processor_hotplug+0xc3/0x140 acpi_soft_cpu_online+0x102/0x1d0 cpuhp_invoke_callback+0x197/0x1120 cpuhp_thread_fun+0x252/0x2f0 smpboot_thread_fn+0x255/0x440 kthread+0x1f4/0x220 ret_from_fork+0x27/0x50 Signed-off-by: Qian Cai <cai@lca.pw> --- v3: Remove #ifdef since cstate.o should rather depend on ACPI_PROCESSOR_IDLE per Rafael. v2: Make call_on_cpu() a static inline function to avoid a compilation error when ACPI_PROCESSOR=m thanks to lkp@intel.com. arch/x86/kernel/acpi/cstate.c | 3 ++- drivers/acpi/processor_throttling.c | 7 ------- include/acpi/processor.h | 8 ++++++++ 3 files changed, 10 insertions(+), 8 deletions(-)