On Thu, Jun 10, 2010 at 10:58 PM, Giovanni Trematerra
<giovanni.tremate...@gmail.com> wrote:
> On Tue, May 4, 2010 at 6:35 PM, David DEMELIER <demelier.da...@gmail.com>
> wrote:
>> Good news ! It worked, check the picture here :
>>
>> http://img63.imageshack.us/img63/4244/dsc00361g.jpg
>>
>
> Into the file sys/dev/acpica/acpi_cpu.c at the end of acpi_cpu_notify
> (a per cpu notification handler), called when _CST objects changing,
> global cpu_cx_count is set to the greatest value of all sc->cpu_cx_count
> per-cpu variables. That could result in a panic as David reported,
> because that lets to invoke acpi_cpu_global_cx_lowest_sysctl from
> /etc/rc.d/power_profile, when AC adapter is unplugged, with a value
> that not all the CPUs could handle in the acpi_cpu_idle.
> The patch also change global cpu_cx_lowest according to new value of
> global cpu_cx_count if needed.
>
> David Demelier made a great work to test every patch I sent him
> to identify the source of the problem.
>
> Please, let me know your comments and possibly commit the patch
> if you think is good enough.
As jhb@ pointed me out in private with the previous patch a CPU could
never enter in the
lowest Cx-state even if it gained.
So I'd like to propose this new solution.
When hw.acpi.cpu.cx_lowest sysctl is set, the global handler in
sys/dev/acpi_cpu.c
will set the greatest sc->cpu_cx_lowest value supported by the CPU and
not the same
value for all CPUs.
Later, when CPU, possibly gain new Cx-states, the acpi_cpu_notify
handler will set
sc->cpu_cx_lowest accordingly with global cx_lowest and the Cx-states
supported by
the CPU.
Now I think that /etc/rc.d/power_profile script has a problem but that
is a different story.
The script select the lowest_value only querying cx-states of the dev.cpu.0.
If different CPUs may have different Cx-states, the script should use
as lowest_value the
lowest value between all the CPUs.
Please, let me know your comments and possibly commit the patch
if you think is good enough.
--
Gianni
diff -r ac95a73d358d sys/dev/acpica/acpi_cpu.c
--- a/sys/dev/acpica/acpi_cpu.c Tue May 18 08:13:40 2010 -0400
+++ b/sys/dev/acpica/acpi_cpu.c Fri Jun 11 03:10:37 2010 -0400
@@ -1009,6 +1009,8 @@ acpi_cpu_notify(ACPI_HANDLE h, UINT32 no
if (isc->cpu_cx_count > cpu_cx_count)
cpu_cx_count = isc->cpu_cx_count;
}
+ if (sc->cpu_cx_lowest < cpu_cx_lowest)
+ acpi_cpu_set_cx_lowest(sc, min(cpu_cx_lowest, sc->cpu_cx_count - 1));
ACPI_SERIAL_END(cpu);
}
@@ -1204,7 +1206,7 @@ acpi_cpu_global_cx_lowest_sysctl(SYSCTL_
ACPI_SERIAL_BEGIN(cpu);
for (i = 0; i < cpu_ndevices; i++) {
sc = device_get_softc(cpu_devices[i]);
- acpi_cpu_set_cx_lowest(sc, val);
+ acpi_cpu_set_cx_lowest(sc, min(val, sc->cpu_cx_count - 1));
}
ACPI_SERIAL_END(cpu);
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