Messages in this thread | | | Date | Mon, 31 Mar 2008 13:42:33 -0400 | From | Mark Lord <> | Subject | Re: 2.6.25 regression: powertop says 120K wakeups/sec |
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Rafael J. Wysocki wrote: > On Friday, 28 of March 2008, Venki Pallipadi wrote: >> On Fri, Mar 28, 2008 at 03:09:22PM -0700, David Brownell wrote: >>> On Friday 28 March 2008, Pallipadi, Venkatesh wrote: >>>> You should have a dmesg line which looks like >>>> ACPI: CPU0 (power states: C1[C1] C2[C2] >>>> Do you see C2 in such line? >>> Yes: >>> >>> ACPI: CPU0 (power states: C1[C1] C2[C2]) >> >> David, >> >> I think I figured out the bug... >> >> Can you try the below patch and confirm that it works (over upstream - ignore >> the earlier revert patch I sent to you). >> >> Thanks, >> Venki >> >> ---- >> >> >> Patch to fix huge number of wakeups reported due to recent changes in >> processor_idle.c. The problem was that the entry_method determination was >> broken due to one of the recent commits (bc71bec91f987) causing >> C1 entry to not to go to halt. This should also fix the hang reported here. >> http://bugzilla.kernel.org/show_bug.cgi?id=10093 > > Ah, thanks for figuring that out. As a regression fix, it should go upstream > ASAP, I think. ..
Would this have any applicability to 2.6.24 as well?
I have seen/reported a similar bug there many times in the past, with no resolution. There's even a bugzilla entry for it somewhere. ???
>> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> >> >> --- >> drivers/acpi/processor_idle.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> Index: linux-2.6/drivers/acpi/processor_idle.c >> =================================================================== >> --- linux-2.6.orig/drivers/acpi/processor_idle.c 2008-03-28 15:31:13.000000000 -0700 >> +++ linux-2.6/drivers/acpi/processor_idle.c 2008-03-28 15:40:50.000000000 -0700 >> @@ -848,6 +848,7 @@ static int acpi_processor_get_power_info >> /* all processors need to support C1 */ >> pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1; >> pr->power.states[ACPI_STATE_C1].valid = 1; >> + pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT; >> } >> /* the C0 state only exists as a filler in our array */ >> pr->power.states[ACPI_STATE_C0].valid = 1; >> @@ -960,6 +961,9 @@ static int acpi_processor_get_power_info >> cx.address); >> } >> >> + if (cx.type == ACPI_STATE_C1) { >> + cx.valid = 1; >> + } >> >> obj = &(element->package.elements[2]); >> if (obj->type != ACPI_TYPE_INTEGER) >> >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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