On Thu, 02 Jul 2009 15:16:03 -0400 Valdis.Kletnieks@xxxxxx wrote: > On Tue, 30 Jun 2009 12:51:30 PDT, akpm@xxxxxxxxxxxxxxxxxxxx said: > > The mm-of-the-moment snapshot 2009-06-30-12-50 has been uploaded to > > > > http://userweb.kernel.org/~akpm/mmotm/ > > This whinges at me during early startup: > > [ 0.654180] ACPI: Video Device [VID] (multi-head: yes rom: no post: no) > [ 0.655101] ACPI: SSDT 000000007fe82138 00244 (v01 PmRef Cpu0Ist 00003000 INTL 20050624) > [ 0.655547] power_supply AC: prop ONLINE=1 > [ 0.655984] ACPI: SSDT 000000007fe81eed 001C6 (v01 PmRef Cpu0Cst 00003001 INTL 20050624) > [ 0.657061] ------------[ cut here ]------------ > [ 0.657296] WARNING: at kernel/lockdep.c:2143 trace_hardirqs_on_caller+0xc7/0x145() > [ 0.657664] Hardware name: Latitude D820 > [ 0.657933] Modules linked in: > [ 0.658056] Pid: 0, comm: swapper Not tainted 2.6.31-rc1-mmotm0630 #1 > [ 0.658056] Call Trace: > [ 0.658056] <IRQ> [<ffffffff8103ef3d>] warn_slowpath_common+0x77/0x8f > [ 0.658056] [<ffffffff8120a76a>] ? acpi_processor_get_throttling_fadt+0x81/0x8c > [ 0.658056] [<ffffffff8103ef64>] warn_slowpath_null+0xf/0x11 > [ 0.658056] [<ffffffff81065ba9>] trace_hardirqs_on_caller+0xc7/0x145 > [ 0.658056] [<ffffffff81065c34>] trace_hardirqs_on+0xd/0xf > [ 0.658056] [<ffffffff8120a76a>] acpi_processor_get_throttling_fadt+0x81/0x8c > [ 0.658056] [<ffffffff8120a3c4>] get_throttling+0x18/0x1f > [ 0.658056] [<ffffffff8106dbbf>] generic_smp_call_function_single_interrupt+0x73/0x95 > [ 0.658056] [<ffffffff8101e9bf>] smp_call_function_single_interrupt+0x13/0x23 > [ 0.658056] [<ffffffff8100c093>] call_function_single_interrupt+0x13/0x20 > [ 0.658056] <EOI> [<ffffffff81012a52>] ? mwait_idle+0x7a/0x95 > [ 0.658056] [<ffffffff81012a49>] ? mwait_idle+0x71/0x95 > [ 0.658056] [<ffffffff814a8d49>] ? atomic_notifier_call_chain+0xf/0x11 > [ 0.658056] [<ffffffff8100a4aa>] ? enter_idle+0x20/0x22 > [ 0.658056] [<ffffffff8100a521>] ? cpu_idle+0x75/0xfd > [ 0.658056] [<ffffffff8148bc41>] ? rest_init+0x75/0x77 > [ 0.658056] [<ffffffff81801c53>] ? start_kernel+0x36e/0x379 > [ 0.658056] [<ffffffff8180129c>] ? x86_64_start_reservations+0xac/0xb0 > [ 0.658056] [<ffffffff81801384>] ? x86_64_start_kernel+0xe4/0xeb > [ 0.658056] ---[ end trace a7919e7f17c0a725 ]--- > [ 0.803166] ACPI: CPU0 (power states: C1[C1] C2[C2] C3[C3]) > [ 0.814078] processor LNXCPU:00: registered as cooling_device0 > [ 0.825244] ACPI: Processor [CPU0] (supports 8 throttling states) apart from having a crappy title, linux-next's : commit f29876421ec11f7d66f3d982219ef3af9bcccf32 : Author: Rusty Russell <rusty@xxxxxxxxxxxxxxx> : AuthorDate: Wed Jul 1 12:37:19 2009 +1000 : Commit: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> : CommitDate: Wed Jul 1 12:37:19 2009 +1000 : : misc:work_on_cpu-acpi : causes get_throttling() to newly be called from an IPI, and lockdep doesn't like irq-disabled interrupt handlers doing local_irq_enable(). If we rely upon these functions only ever being called from smp_call_function_single(), and if smp_call_function_single() is correctly implemented, we should be able to do this: --- a/drivers/acpi/processor_throttling.c~a +++ a/drivers/acpi/processor_throttling.c @@ -616,6 +616,8 @@ static int acpi_processor_get_throttling u32 duty_mask = 0; u32 duty_value = 0; + WARN_ON_ONCE(!irqs_disabled()); + if (!pr) return -EINVAL; @@ -628,8 +630,6 @@ static int acpi_processor_get_throttling duty_mask <<= pr->throttling.duty_offset; - local_irq_disable(); - value = inl(pr->throttling.address); /* @@ -646,8 +646,6 @@ static int acpi_processor_get_throttling pr->throttling.state = state; - local_irq_enable(); - ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling state is T%d (%d%% throttling applied)\n", state, pr->throttling.states[state].performance)); @@ -919,6 +917,8 @@ static int acpi_processor_set_throttling u32 duty_mask = 0; u32 duty_value = 0; + WARN_ON_ONCE(!irqs_disabled()); + if (!pr) return -EINVAL; @@ -948,8 +948,6 @@ static int acpi_processor_set_throttling duty_mask = ~duty_mask; } - local_irq_disable(); - /* * Disable throttling by writing a 0 to bit 4. Note that we must * turn it off before you can change the duty_value. @@ -975,8 +973,6 @@ static int acpi_processor_set_throttling pr->throttling.state = state; - local_irq_enable(); - ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Throttling state set to T%d (%d%%)\n", state, (pr->throttling.states[state].performance ? pr-> _ -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
