Messages in this thread | | | From | Vladyslav Frolov <> | Date | Mon, 21 Mar 2016 18:14:53 +0700 | Subject | Re: [REGRESSION] 774ac8b7eff6 ("Thermal: initialize thermal zone device correctly") causes performance drop |
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Hi Rui,
I'm sorry for the delay; Reading the e-mail the first time I have missed the part about the patch, so I'm building the kernel now.
By the way, the patch reported a slight offset missmatch:
patching file drivers/thermal/thermal_core.c Hunk #2 succeeded at 1800 (offset -4 lines). Hunk #3 succeeded at 1872 (offset -4 lines).
Is this fine?
On 21 March 2016 at 18:09, Vladyslav Frolov <frolvlad@gmail.com> wrote: > Hi Rui, > > I'm sorry for the delay; Reading the e-mail the first time I have missed the > part about the patch, so I'm building the kernel now. > > By the way, the patch reported a slight offset missmatch: > > patching file drivers/thermal/thermal_core.c > Hunk #2 succeeded at 1800 (offset -4 lines). > Hunk #3 succeeded at 1872 (offset -4 lines). > > Is this fine? > > > > On 19 March 2016 at 11:43, Zhang Rui <rui.zhang@intel.com> wrote: >> >> >> Hi, all, >> >> On Wed, 2016-03-16 at 15:27 -0700, Laura Abbott wrote: >> > Hi, >> > >> > Fedora received a bug report >> > (https://bugzilla.redhat.com/show_bug.cgi?id=1317190) >> > of a major performance drop on various bench marks and general system >> > sluggishness with the 4.4.4 kernel update. The benchmarks were showing >> > a reduction to about 18% performance (not minor). >> > >> > Bisection showed the first bad commit was >> > >> > commit 774ac8b7eff69e0786970157de2157e68b22f456 >> > Author: Zhang Rui <rui.zhang@intel.com> >> > Date: Fri Oct 30 16:31:47 2015 +0800 >> > >> > Thermal: initialize thermal zone device correctly >> > >> > commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 upstream. >> > >> > After thermal zone device registered, as we have not read any >> > temperature before, thus tz->temperature should not be 0, >> > which actually means 0C, and thermal trend is not available. >> > In this case, we need specially handling for the first >> > thermal_zone_device_update(). >> > >> > Both thermal core framework and step_wise governor is >> > enhanced to handle this. And since the step_wise governor >> > is the only one that uses trends, so it's the only thermal >> > governor that needs to be updated. >> > >> > Tested-by: Manuel Krause <manuelkrause@netscape.net> >> > Tested-by: szegad <szegadlo@poczta.onet.pl> >> > Tested-by: prash <prash.n.rao@gmail.com> >> > Tested-by: amish <ammdispose-arch@yahoo.com> >> > Tested-by: Matthias <morpheusxyz123@yahoo.de> >> > Reviewed-by: Javi Merino <javi.merino@arm.com> >> > Signed-off-by: Zhang Rui <rui.zhang@intel.com> >> > Signed-off-by: Chen Yu <yu.c.chen@intel.com> >> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >> >> According to https://bugzilla.redhat.com/show_bug.cgi?id=1317190#c30 >> and https://bugzilla.kernel.org/show_bug.cgi?id=114551, >> the root cause of the problem is that >> 1. BIOS reports bogus passive trip point value, which is 0 degree >> Celsius >> 2. Without the thermal patches, thermal core does nothing upon driver >> probe, thus processor cooling states are not changed. >> 3. With the thermal patches applied, thermal core checks the new >> registered thermal zone driver when it is probed, and set the cooling >> devices to proper state, for example, fan device could be spinning >> during boot, even if the system is cool. >> 4. Thus, on these Lenovo laptops, processor cooling devices are >> throttled because the current temperature (around 50C) is higher than >> the passive trip point (0C), and the thermal zone is considered as >> overheating. >> >> In order to workaround this bogus BIOS, we should disable those invalid >> trip points by checking the trip point value, like the patch below, >> Laura and Vlad, >> can you please try the patch below and confirm if it fixes the problem >> for you? >> >> From 81ad4276b505e987dd8ebbdf63605f92cd172b52 Mon Sep 17 00:00:00 2001 >> From: Zhang Rui <rui.zhang@intel.com> >> Date: Fri, 18 Mar 2016 10:03:24 +0800 >> Subject: [PATCH] Thermal: Ignore invalid trip points >> >> In some cases, platform thermal driver may report invalid trip points, >> thermal core should not take any action for these trip points. >> >> This fixed a regression that bogus trip point starts to screw up thermal >> control on some Lenovo laptops, after >> commit bb431ba26c5cd0a17c941ca6c3a195a3a6d5d461 >> Author: Zhang Rui <rui.zhang@intel.com> >> Date: Fri Oct 30 16:31:47 2015 +0800 >> >> Thermal: initialize thermal zone device correctly >> >> After thermal zone device registered, as we have not read any >> temperature before, thus tz->temperature should not be 0, >> which actually means 0C, and thermal trend is not available. >> In this case, we need specially handling for the first >> thermal_zone_device_update(). >> >> Both thermal core framework and step_wise governor is >> enhanced to handle this. And since the step_wise governor >> is the only one that uses trends, so it's the only thermal >> governor that needs to be updated. >> >> Tested-by: Manuel Krause <manuelkrause@netscape.net> >> Tested-by: szegad <szegadlo@poczta.onet.pl> >> Tested-by: prash <prash.n.rao@gmail.com> >> Tested-by: amish <ammdispose-arch@yahoo.com> >> Tested-by: Matthias <morpheusxyz123@yahoo.de> >> Reviewed-by: Javi Merino <javi.merino@arm.com> >> Signed-off-by: Zhang Rui <rui.zhang@intel.com> >> Signed-off-by: Chen Yu <yu.c.chen@intel.com> >> >> CC: <stable@vger.kernel.org> #3.18+ >> Link: https://bugzilla.redhat.com/show_bug.cgi?id=1317190 >> Link: https://bugzilla.kernel.org/show_bug.cgi?id=114551 >> Signed-off-by: Zhang Rui <rui.zhang@intel.com> >> --- >> drivers/thermal/thermal_core.c | 13 ++++++++++++- >> include/linux/thermal.h | 2 ++ >> 2 files changed, 14 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/thermal/thermal_core.c >> b/drivers/thermal/thermal_core.c >> index a0a8fd1..d4b5465 100644 >> --- a/drivers/thermal/thermal_core.c >> +++ b/drivers/thermal/thermal_core.c >> @@ -454,6 +454,10 @@ static void handle_thermal_trip(struct >> thermal_zone_device *tz, int trip) >> { >> enum thermal_trip_type type; >> >> + /* Ignore disabled trip points */ >> + if (test_bit(trip, &tz->trips_disabled)) >> + return; >> + >> tz->ops->get_trip_type(tz, trip, &type); >> >> if (type == THERMAL_TRIP_CRITICAL || type == THERMAL_TRIP_HOT) >> @@ -1800,6 +1804,7 @@ struct thermal_zone_device >> *thermal_zone_device_register(const char *type, >> { >> struct thermal_zone_device *tz; >> enum thermal_trip_type trip_type; >> + int trip_temp; >> int result; >> int count; >> int passive = 0; >> @@ -1871,9 +1876,15 @@ struct thermal_zone_device >> *thermal_zone_device_register(const char *type, >> goto unregister; >> >> for (count = 0; count < trips; count++) { >> - tz->ops->get_trip_type(tz, count, &trip_type); >> + if (tz->ops->get_trip_type(tz, count, &trip_type)) >> + set_bit(count, &tz->trips_disabled); >> if (trip_type == THERMAL_TRIP_PASSIVE) >> passive = 1; >> + if (tz->ops->get_trip_temp(tz, count, &trip_temp)) >> + set_bit(count, &tz->trips_disabled); >> + /* Check for bogus trip points */ >> + if (trip_temp == 0) >> + set_bit(count, &tz->trips_disabled); >> } >> >> if (!passive) { >> diff --git a/include/linux/thermal.h b/include/linux/thermal.h >> index 9c48199..a55d052 100644 >> --- a/include/linux/thermal.h >> +++ b/include/linux/thermal.h >> @@ -156,6 +156,7 @@ struct thermal_attr { >> * @trip_hyst_attrs: attributes for trip points for sysfs: trip >> hysteresis >> * @devdata: private pointer for device private data >> * @trips: number of trip points the thermal zone supports >> + * @trips_disabled; bitmap for disabled trips >> * @passive_delay: number of milliseconds to wait between polls when >> * performing passive cooling. >> * @polling_delay: number of milliseconds to wait between polls when >> @@ -191,6 +192,7 @@ struct thermal_zone_device { >> struct thermal_attr *trip_hyst_attrs; >> void *devdata; >> int trips; >> + unsigned long trips_disabled; /* bitmap for disabled trips */ >> int passive_delay; >> int polling_delay; >> int temperature; >> -- >> 1.9.1 >> >> >> >
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