Existing platforms, which do not support operating-points-v2, can
explicitly tell the opp core that some of the CPUs share opp tables,
with help of dev_pm_opp_set_sharing_cpus().
For such platforms, explicitly ask the opp core to provide list of CPUs
sharing the opp table with current cpu device, before falling back to
platform data.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The name of the prev_cpu_wall field in struct cpu_dbs_info is
confusing, because it doesn't represent wall time, but the previous
update time as returned by get_cpu_idle_time() (that may be the
current value of jiffies_64 in some cases, for example).
Moreover, the names of some related variables in dbs_update() take
that confusion further.
Rename all of those things to make their names reflect the purpose
more accurately. While at it, drop unnecessary parens from one of
the updated expressions.
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Chen Yu <yu.c.chen@intel.com>
For platforms which are controlled via remove node manager, enable _PPC by
default. These platforms are mostly categorized as enterprise server or
performance servers. These platforms needs to go through some
certifications tests, which tests control via _PPC.
The relative risk of enabling by default is low as this is is less likely
that these systems have broken _PSS table.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When policy->max is changed via _PPC or sysfs and is more than the max non
turbo frequency, it does not really change resulting performance in some
processors. When policy->max results in a P-State ratio more than the
turbo activation ratio, then processor can choose any P-State up to max
turbo. So the user or _PPC setting has no value, but this can cause
undesirable side effects like:
- Showing reduced max percentage in Intel P-State sysfs
- It can cause reduced max performance under certain boundary conditions:
The requested max scaling frequency either via _PPC or via cpufreq-sysfs,
will be converted into a fixed floating point max percent scale. In
majority of the cases this will result in correct max. But not 100% of the
time. If the _PPC is requested at a point where the calculation lead to a
lower max, this can result in a lower P-State then expected and it will
impact performance.
Example of this condition using a Broadwell laptop with config TDP.
ACPI _PSS table from a Broadwell laptop
2301000 2300000 2200000 2000000 1900000 1800000 1700000 1500000 1400000
1300000 1100000 1000000 900000 800000 600000 500000
The actual results by disabling config TDP so that we can get what is
requested on or below 2300000Khz.
scaling_max_freq Max Requested P-State Resultant scaling
max
---------------------------------------- ----------------------
2400000 18 2900000 (max
turbo)
2300000 17 2300000 (max
physical non turbo)
2200000 15 2100000
2100000 15 2100000
2000000 13 1900000
1900000 13 1900000
1800000 12 1800000
1700000 11 1700000
1600000 10 1600000
1500000 f 1500000
1400000 e 1400000
1300000 d 1300000
1200000 c 1200000
1100000 a 1000000
1000000 a 1000000
900000 9 900000
800000 8 800000
700000 7 700000
600000 6 600000
500000 5 500000
------------------------------------------------------------------
Now set the config TDP level 1 ratio as 0x0b (equivalent to 1100000KHz)
in BIOS (not every system will let you adjust this).
The turbo activation ratio will be set to one less than that, which will
be 0x0a (So any request above 1000000KHz should result in turbo region
assuming no thermal limits).
Here _PPC will request max to 1100000KHz (which basically should still
result in turbo as this is more than the turbo activation ratio up to
max allowable turbo frequency), but actual calculation resulted in a max
ceiling P-State which is 0x0a. So under any load condition, this driver
will not request turbo P-States. This will be a huge performance hit.
When config TDP feature is ON, if the _PPC points to a frequency above
turbo activation ratio, the performance can still reach max turbo. In this
case we don't need to treat this as the reduced frequency in set_policy
callback.
In this change when config TDP is active (by checking if the physical max
non turbo ratio is more than the current max non turbo ratio), any request
above current max non turbo is treated as full performance.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw : Minor cleanups ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Use ACPI _PPC notification to limit max P state driver will request.
ACPI _PPC change notification is sent by BIOS to limit max P state
in several cases:
- Reduce impact of platform thermal condition
- When Config TDP feature is used, a changed _PPC is sent to
follow TDP change
- Remote node managers in server want to control platform power
via baseboard management controller (BMC)
This change registers with ACPI processor performance lib so that
_PPC changes are notified to cpufreq core, which in turns will
result in call to .setpolicy() callback. Also the way _PSS
table identifies a turbo frequency is not compatible to max turbo
frequency in intel_pstate, so the very first entry in _PSS needs
to be adjusted.
This feature can be turned on by using kernel parameters:
intel_pstate=support_acpi_ppc
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
[ rjw: Minor cleanups ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The frequency transition latency from pmin to pmax is observed to be in
few millisecond granurality. And it usually happens to take a performance
penalty during sudden frequency rampup requests.
This patch set solves this problem by using an entity called "global
pstates". The global pstate is a Chip-level entity, so the global entitiy
(Voltage) is managed across the cores. The local pstate is a Core-level
entity, so the local entity (frequency) is managed across threads.
This patch brings down global pstate at a slower rate than the local
pstate. Hence by holding global pstates higher than local pstate makes
the subsequent rampups faster.
A per policy structure is maintained to keep track of the global and
local pstate changes. The global pstate is brought down using a parabolic
equation. The ramp down time to pmin is set to ~5 seconds. To make sure
that the global pstates are dropped at regular interval , a timer is
queued for every 2 seconds during ramp-down phase, which eventually brings
the pstate down to local pstate.
Iozone results show fairly consistent performance boost.
YCSB on redis shows improved Max latencies in most cases.
Iozone write/rewite test were made with filesizes 200704Kb and 401408Kb
with different record sizes . The following table shows IOoperations/sec
with and without patch.
Iozone Results ( in op/sec) ( mean over 3 iterations )
---------------------------------------------------------------------
file size- with without %
recordsize-IOtype patch patch change
----------------------------------------------------------------------
200704-1-SeqWrite 1616532 1615425 0.06
200704-1-Rewrite 2423195 2303130 5.21
200704-2-SeqWrite 1628577 1602620 1.61
200704-2-Rewrite 2428264 2312154 5.02
200704-4-SeqWrite 1617605 1617182 0.02
200704-4-Rewrite 2430524 2351238 3.37
200704-8-SeqWrite 1629478 1600436 1.81
200704-8-Rewrite 2415308 2298136 5.09
200704-16-SeqWrite 1619632 1618250 0.08
200704-16-Rewrite 2396650 2352591 1.87
200704-32-SeqWrite 1632544 1598083 2.15
200704-32-Rewrite 2425119 2329743 4.09
200704-64-SeqWrite 1617812 1617235 0.03
200704-64-Rewrite 2402021 2321080 3.48
200704-128-SeqWrite 1631998 1600256 1.98
200704-128-Rewrite 2422389 2304954 5.09
200704-256 SeqWrite 1617065 1616962 0.00
200704-256-Rewrite 2432539 2301980 5.67
200704-512-SeqWrite 1632599 1598656 2.12
200704-512-Rewrite 2429270 2323676 4.54
200704-1024-SeqWrite 1618758 1616156 0.16
200704-1024-Rewrite 2431631 2315889 4.99
401408-1-SeqWrite 1631479 1608132 1.45
401408-1-Rewrite 2501550 2459409 1.71
401408-2-SeqWrite 1617095 1626069 -0.55
401408-2-Rewrite 2507557 2443621 2.61
401408-4-SeqWrite 1629601 1611869 1.10
401408-4-Rewrite 2505909 2462098 1.77
401408-8-SeqWrite 1617110 1626968 -0.60
401408-8-Rewrite 2512244 2456827 2.25
401408-16-SeqWrite 1632609 1609603 1.42
401408-16-Rewrite 2500792 2451405 2.01
401408-32-SeqWrite 1619294 1628167 -0.54
401408-32-Rewrite 2510115 2451292 2.39
401408-64-SeqWrite 1632709 1603746 1.80
401408-64-Rewrite 2506692 2433186 3.02
401408-128-SeqWrite 1619284 1627461 -0.50
401408-128-Rewrite 2518698 2453361 2.66
401408-256-SeqWrite 1634022 1610681 1.44
401408-256-Rewrite 2509987 2446328 2.60
401408-512-SeqWrite 1617524 1628016 -0.64
401408-512-Rewrite 2504409 2442899 2.51
401408-1024-SeqWrite 1629812 1611566 1.13
401408-1024-Rewrite 2507620 2442968 2.64
Tested with YCSB workload (50% update + 50% read) over redis for 1 million
records and 1 million operation. Each test was carried out with target
operations per second and persistence disabled.
Max-latency (in us)( mean over 5 iterations )
---------------------------------------------------------------
op/s Operation with patch without patch %change
---------------------------------------------------------------
15000 Read 61480.6 50261.4 22.32
15000 cleanup 215.2 293.6 -26.70
15000 update 25666.2 25163.8 2.00
25000 Read 32626.2 89525.4 -63.56
25000 cleanup 292.2 263.0 11.10
25000 update 32293.4 90255.0 -64.22
35000 Read 34783.0 33119.0 5.02
35000 cleanup 321.2 395.8 -18.8
35000 update 36047.0 38747.8 -6.97
40000 Read 38562.2 42357.4 -8.96
40000 cleanup 371.8 384.6 -3.33
40000 update 27861.4 41547.8 -32.94
45000 Read 42271.0 88120.6 -52.03
45000 cleanup 263.6 383.0 -31.17
45000 update 29755.8 81359.0 -63.43
(test without target op/s)
47659 Read 83061.4 136440.6 -39.12
47659 cleanup 195.8 193.8 1.03
47659 update 73429.4 124971.8 -41.24
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
commit 1b0289848d ("cpufreq: powernv: Add sysfs attributes to show
throttle stats") used policy->driver_data as a flag for one-time creation
of throttle sysfs files. Instead of this use 'kernfs_find_and_get()' to
check if the attribute already exists. This is required as
policy->driver_data is used for other purposes in the later patch.
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The IS_ENABLED() macro checks if a Kconfig symbol has been enabled either
built-in or as a module, use that macro instead of open coding the same.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When the config TDP level is not nominal (level = 0), the MSR values for
reading level 1 and level 2 ratios contain power in low 14 bits and actual
ratio bits are at bits [23:16]. The current processing for level 1 and
level 2 is wrong as there is no shift done to get actual ratio.
Fixes: 6a35fc2d6c (cpufreq: intel_pstate: get P1 from TAR when available)
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: 4.4+ <stable@vger.kernel.org> # 4.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The way cpufreq_governor_start() initializes j_cdbs->prev_load is
questionable.
First off, j_cdbs->prev_cpu_wall used as a denominator in the
computation may be zero. The case this happens is when
get_cpu_idle_time_us() returns -1 and get_cpu_idle_time_jiffy()
used to return that number is called exactly at the jiffies_64
wrap time. It is rather hard to trigger that error, but it is not
impossible and it will just crash the kernel then.
Second, j_cdbs->prev_load is computed as the average load during
the entire time since the system started and it may not reflect the
load in the previous sampling period (as it is expected to).
That doesn't play well with the way dbs_update() uses that value.
Namely, if the update time delta (wall_time) happens do be greater
than twice the sampling rate on the first invocation of it, the
initial value of j_cdbs->prev_load (which may be completely off) will
be returned to the caller as the current load (unless it is equal to
zero and unless another CPU sharing the same policy object has a
greater load value).
For this reason, notice that the prev_load field of struct cpu_dbs_info
is only used by dbs_update() and only in that one place, so if
cpufreq_governor_start() is modified to always initialize it to 0,
it will make dbs_update() always compute the actual load first time
it checks the update time delta against the doubled sampling rate
(after initialization) and there won't be any side effects of it.
Consequently, modify cpufreq_governor_start() as described.
Fixes: 18b46abd00 (cpufreq: governor: Be friendly towards latency-sensitive bursty workloads)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The cpufreq-dt-platdev driver supports creation of cpufreq-dt platform
device now, reuse that and remove similar code from platform code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq-dt-platdev driver supports creation of cpufreq-dt platform
device now, reuse that and remove similar code from platform code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq-dt-platdev driver supports creation of cpufreq-dt platform
device now, reuse that and remove similar code from platform code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq-dt-platdev driver supports creation of cpufreq-dt platform
device now, reuse that and remove similar code from platform code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch add rockchip's compatible string to the compat list and
remove similar code from platform code for supporting generic platdev
driver.
Signed-off-by: Finley Xiao <finley.xiao@rock-chips.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq-dt-platdev driver supports creation of cpufreq-dt platform
device now, reuse that and remove similar code from platform code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq-dt-platdev driver supports creation of cpufreq-dt platform
device now, reuse that and remove similar code from platform code.
Note that the complete routine imx27_dt_init() is removed as
of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
has same effect as a NULL .init_machine machine callback pointer.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq-dt-platdev driver supports creation of cpufreq-dt platform
device now, reuse that and remove similar code from platform code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The machines array in cpufreq-dt-platdev is used only once at boot time
and so should be marked with __initconst, so that kernel can free up
memory used for it, if required.
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cooling device is registered by ready callback. It's also invoked while
system resuming from sleep (Enabling non-boot cpus). Thus cooling device
may be multiple registered. Matchable unregistration is added to exit
callback to fix this issue.
Signed-off-by: Jia Hongtao <hongtao.jia@nxp.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
.exit callback (qoriq_cpufreq_cpu_exit()) is also used during suspend.
So __exit macro should be removed or the function will be discarded.
Signed-off-by: Jia Hongtao <hongtao.jia@nxp.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When THERMAL_OF is undefined the cooling device messages should not be
shown. -ENOSYS is returned from of_cpufreq_cooling_register() when
THERMAL_OF is undefined.
Signed-off-by: Jia Hongtao <hongtao.jia@nxp.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a function to cleanup at module exit and export
appropriate GPL string to enable moduler support
for the cppc_cpufreq driver.
Reported-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com>
Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The result returned by pid_calc() is subtracted from current_pstate
(which is the P-State requested during the last period) in order to
obtain the target P-State for the current iteration.
However, current_pstate may not reflect the real current P-State of
the CPU. In particular, that P-State may be higher because of the
frequency sharing per module.
The theory is:
- The load is the percentage of time spent in C0 and is related to
the average P-State during the same period.
- The last requested P-State can be completely different than the
average P-State (because of frequency sharing or throttling).
- The P-State shift computed by the pid_calc is based on the load
computed at average P-State, so the shift must be relative to
this average P-State.
Using the average P-State instead of current P-State improves power
without significant performance penalty in cases when a task migrates
from one core to other core sharing frequency and voltage.
Performance and power comparison with this patch on Cherry Trail
platform using Android:
Benchmark ?Perf ?Power
FishTank 10.45% 3.1%
SmartBench-Gaming -0.1% -10.4%
SmartBench-Productivity -0.8% -10.4%
CandyCrush n/a -17.4%
AngryBirds n/a -5.9%
videoPlayback n/a -13.9%
audioPlayback n/a -4.9%
IcyRocks-20-50 0.0% -38.4%
iozone RR -0.16% -1.3%
iozone RW 0.74% -1.3%
Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Revert commit 0df35026c6 (cpufreq: governor: Fix negative idle_time
when configured with CONFIG_HZ_PERIODIC) that introduced a regression
by causing the ondemand cpufreq governor to misbehave for
CONFIG_TICK_CPU_ACCOUNTING unset (the frequency goes up to the max at
one point and stays there indefinitely).
The revert takes subsequent modifications of the code in question into
account.
Fixes: 0df35026c6 (cpufreq: governor: Fix negative idle_time when configured with CONFIG_HZ_PERIODIC)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=115261
Reported-and-tested-by: Timo Valtoaho <timo.valtoaho@gmail.com>
Cc: 4.5+ <stable@vger.kernel.org> # 4.5+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
* pm-cpufreq-fixes:
cpufreq: Abort cpufreq_update_current_freq() for cpufreq_suspended set
intel_pstate: Avoid getting stuck in high P-states when idle
Since governor operations are generally skipped if cpufreq_suspended
is set, cpufreq_start_governor() should do nothing in that case.
That function is called in the cpufreq_online() path, and may also
be called from cpufreq_offline() in some cases, which are invoked
by the nonboot CPUs disabing/enabling code during system suspend
to RAM and resume. That happens when all devices have been
suspended, so if the cpufreq driver relies on things like I2C to
get the current frequency, it may not be ready to do that then.
To prevent problems from happening for this reason, make
cpufreq_update_current_freq(), which is the only function invoked
by cpufreq_start_governor() that doesn't check cpufreq_suspended
already, return 0 upfront if cpufreq_suspended is set.
Fixes: 3bbf8fe3ae (cpufreq: Always update current frequency before startig governor)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The Kconfig for this driver is currently:
config CPU_FREQ_CBE_PMI
bool "CBE frequency scaling using PMI interface"
...meaning that it currently is not being built as a module by
anyone. Lets remove the modular and unused code here, so that
when reading the driver there is no doubt it is builtin-only.
Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.
We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Christian Krafft <krafft@de.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-pm@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Jörg Otte reports that commit a4675fbc4a (cpufreq: intel_pstate:
Replace timers with utilization update callbacks) caused the CPUs in
his Haswell-based system to stay in the very high frequency region
even if the system is completely idle.
That turns out to be an existing problem in the intel_pstate driver's
P-state selection algorithm for Core processors. Namely, all
decisions made by that algorithm are based on the average frequency
of the CPU between sampling events and on the P-state requested on
the last invocation, so it may get stuck at a very hight frequency
even if the utilization of the CPU is very low (in fact, it may get
stuck in a inadequate P-state regardless of the CPU utilization).
The only way to kick it out of that limbo is a sufficiently long idle
period (3 times longer than the prescribed sampling interval), but if
that doesn't happen often enough (eg. due to a timing change like
after the above commit), the P-state of the CPU may be inadequate
pretty much all the time.
To address the most egregious manifestations of that issue, reset the
core_busy value used to determine the next P-state to request if the
utilization of the CPU, determined with the help of the MPERF
feedback register and the TSC, is below 1%.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=115771
Reported-and-tested-by: Jörg Otte <jrg.otte@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The freq-table is stored in struct cpufreq_policy also and there is
absolutely no need of keeping a copy of its reference in struct
acpi_cpufreq_data. Drop it.
Also policy->freq_table can't be NULL in the target() callback, remove
the useless check as well.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Rebase ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Its always set by ->init() and so it will always be there in ->exit().
There is no need to have a special check for just that.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Rebase ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reorganize the code in cpufreq_add_dev() to avoid using the ret
variable and reduce the indentation level in it.
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Merge two switch entries that do the same thing in
cpufreq_cpu_callback().
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Use the more common kernel style adding a define for pr_fmt.
Miscellanea:
o Remove now unused PFX defines
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Use the more common logging style.
Miscellanea:
o Coalesce formats
o Realign arguments
o Add a missing space between a coalesced format
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Prefix the output using the more common kernel style.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Rebase ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Use list_for_each_entry*() instead of list_for_each*() to simplify
the code.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are multiple places in intel_pstate where int_tofp() is applied
to both arguments of div_fp(), but this is pointless, because int_tofp()
simply shifts its argument to the left by FRAC_BITS which mathematically
is equivalent to multuplication by 2^FRAC_BITS, so if this is done
to both arguments of a division, the extra factors will cancel each
other during that operation anyway.
Drop the pointless int_tofp() applied to div_fp() arguments throughout
the driver.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq-dt-platdev driver supports creation of cpufreq-dt platform
device now, reuse that and remove similar code from platform code.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Multiple platforms are using the generic cpufreq-dt driver now, and all
of them are required to create a platform device with name "cpufreq-dt",
in order to get the cpufreq-dt probed.
Many of them do it from platform code, others have special drivers just
to do that.
It would be more sensible to do this at a generic place, where all such
platform can mark their entries.
This patch adds a separate file to get this device created. Currently
the compat list of platforms that we support is empty, and will be
filled in as and when we move platforms to use it.
It always compiles as part of the kernel and so doesn't need a
module-exit operation.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
All CPUs on Tegra platform share clock/voltage lines and there is
absolutely no need of setting platform data for 'cpufreq-dt' platform
device, as that's the default case.
Stop setting platform data for cpufreq-dt device.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The Kconfig for this driver is currently:
config CPU_FREQ_CBE_PMI
bool "CBE frequency scaling using PMI interface"
...meaning that it currently is not being built as a module by
anyone. Lets remove the modular and unused code here, so that
when reading the driver there is no doubt it is builtin-only.
Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.
We also delete the MODULE_LICENSE tag etc. since all that information
is already contained at the top of the file in the comments.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Due to differences in the cpufreq core's handling of runtime CPU
offline and nonboot CPUs disabling during system suspend-to-RAM,
fast frequency switching gets disabled after a suspend-to-RAM and
resume cycle on all of the nonboot CPUs.
To prevent that from happening, move the invocation of
cpufreq_disable_fast_switch() from cpufreq_exit_governor() to
sugov_exit(), as the schedutil governor is the only user of fast
frequency switching today anyway.
That simply prevents cpufreq_disable_fast_switch() from being called
without invoking the ->governor callback for the CPUFREQ_GOV_POLICY_EXIT
event (which happens during system suspend now).
Fixes: b7898fda5b (cpufreq: Support for fast frequency switching)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
* pm-cpufreq:
cpufreq: dt: Drop stale comment
cpufreq: intel_pstate: Documenation for structures
cpufreq: intel_pstate: fix inconsistency in setting policy limits
intel_pstate: Avoid extra invocation of intel_pstate_sample()
intel_pstate: Do not set utilization update hook too early
* pm-cpuidle:
intel_idle: Add KBL support
intel_idle: Add SKX support
intel_idle: Clean up all registered devices on exit.
intel_idle: Propagate hot plug errors.
intel_idle: Don't overreact to a cpuidle registration failure.
intel_idle: Setup the timer broadcast only on successful driver load.
intel_idle: Avoid a double free of the per-CPU data.
intel_idle: Fix dangling registration on error path.
intel_idle: Fix deallocation order on the driver exit path.
intel_idle: Remove redundant initialization calls.
intel_idle: Fix a helper function's return value.
intel_idle: remove useless return from void function.
* acpi-cppc:
mailbox: pcc: Don't access an unmapped memory address space
The comment in file header doesn't hold true anymore, drop it.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
No code change. Only added kernel doc style comments for structures.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When user sets performance policy using cpufreq interface, it is possible
that because of policy->max limits, the actual performance is still
limited. But the current implementation will silently switch the
policy to powersave and start using powersave limits. If user modifies
any limits using intel_pstate sysfs, this is actually changing powersave
limits.
The current implementation tracks limits under powersave and performance
policy using two different variables. When policy->max is less than
policy->cpuinfo.max_freq, only powersave limit variable is used.
This fix causes the performance limits variable to be used always when
the policy is performance.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add a new cpufreq scaling governor, called "schedutil", that uses
scheduler-provided CPU utilization information as input for making
its decisions.
Doing that is possible after commit 34e2c555f3 (cpufreq: Add
mechanism for registering utilization update callbacks) that
introduced cpufreq_update_util() called by the scheduler on
utilization changes (from CFS) and RT/DL task status updates.
In particular, CPU frequency scaling decisions may be based on
the the utilization data passed to cpufreq_update_util() by CFS.
The new governor is relatively simple.
The frequency selection formula used by it depends on whether or not
the utilization is frequency-invariant. In the frequency-invariant
case the new CPU frequency is given by
next_freq = 1.25 * max_freq * util / max
where util and max are the last two arguments of cpufreq_update_util().
In turn, if util is not frequency-invariant, the maximum frequency in
the above formula is replaced with the current frequency of the CPU:
next_freq = 1.25 * curr_freq * util / max
The coefficient 1.25 corresponds to the frequency tipping point at
(util / max) = 0.8.
All of the computations are carried out in the utilization update
handlers provided by the new governor. One of those handlers is
used for cpufreq policies shared between multiple CPUs and the other
one is for policies with one CPU only (and therefore it doesn't need
to use any extra synchronization means).
The governor supports fast frequency switching if that is supported
by the cpufreq driver in use and possible for the given policy.
In the fast switching case, all operations of the governor take
place in its utilization update handlers. If fast switching cannot
be used, the frequency switch operations are carried out with the
help of a work item which only calls __cpufreq_driver_target()
(under a mutex) to trigger a frequency update (to a value already
computed beforehand in one of the utilization update handlers).
Currently, the governor treats all of the RT and DL tasks as
"unknown utilization" and sets the frequency to the allowed
maximum when updated from the RT or DL sched classes. That
heavy-handed approach should be replaced with something more
subtle and specifically targeted at RT and DL tasks.
The governor shares some tunables management code with the
"ondemand" and "conservative" governors and uses some common
definitions from cpufreq_governor.h, but apart from that it
is stand-alone.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Modify the ACPI cpufreq driver to provide a method for switching
CPU frequencies from interrupt context and update the cpufreq core
to support that method if available.
Introduce a new cpufreq driver callback, ->fast_switch, to be
invoked for frequency switching from interrupt context by (future)
governors supporting that feature via (new) helper function
cpufreq_driver_fast_switch().
Add two new policy flags, fast_switch_possible, to be set by the
cpufreq driver if fast frequency switching can be used for the
given policy and fast_switch_enabled, to be set by the governor
if it is going to use fast frequency switching for the given
policy. Also add a helper for setting the latter.
Since fast frequency switching is inherently incompatible with
cpufreq transition notifiers, make it possible to set the
fast_switch_enabled only if there are no transition notifiers
already registered and make the registration of new transition
notifiers fail if fast_switch_enabled is set for at least one
policy.
Implement the ->fast_switch callback in the ACPI cpufreq driver
and make it set fast_switch_possible during policy initialization
as appropriate.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Move definitions of symbols related to transition latency and
sampling rate to include/linux/cpufreq.h so they can be used by
(future) goverernors located outside of drivers/cpufreq/.
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Move definitions and function headers related to struct gov_attr_set
to include/linux/cpufreq.h so they can be used by (future) goverernors
located outside of drivers/cpufreq/.
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Move abstract code related to struct gov_attr_set to a separate (new)
file so it can be shared with (future) goverernors that won't share
more code with "ondemand" and "conservative".
No intentional functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
In addition to fields representing governor tunables, struct dbs_data
contains some fields needed for the management of objects of that
type. As it turns out, that part of struct dbs_data may be shared
with (future) governors that won't use the common code used by
"ondemand" and "conservative", so move it to a separate struct type
and modify the code using struct dbs_data to follow.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Replace the single helper for adding and removing cpufreq utilization
update hooks, cpufreq_set_update_util_data(), with a pair of helpers,
cpufreq_add_update_util_hook() and cpufreq_remove_update_util_hook(),
and modify the users of cpufreq_set_update_util_data() accordingly.
With the new helpers, the code using them doesn't need to worry
about the internals of struct update_util_data and in particular
it doesn't need to worry about populating the func field in it
properly upfront.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
The initialization of intel_pstate for a given CPU involves populating
the fields of its struct cpudata that represent the previous sample,
but currently that is done in a problematic way.
Namely, intel_pstate_init_cpu() makes an extra call to
intel_pstate_sample() so it reads the current register values that
will be used to populate the "previous sample" record during the
next invocation of intel_pstate_sample(). However, after commit
a4675fbc4a (cpufreq: intel_pstate: Replace timers with utilization
update callbacks) that doesn't work for last_sample_time, because
the time value is passed to intel_pstate_sample() as an argument now.
Passing 0 to it from intel_pstate_init_cpu() is problematic, because
that causes cpu->last_sample_time == 0 to be visible in
get_target_pstate_use_performance() (and hence the extra
cpu->last_sample_time > 0 check in there) and effectively allows
the first invocation of intel_pstate_sample() from
intel_pstate_update_util() to happen immediately after the
initialization which may lead to a significant "turn on"
effect in the governor algorithm.
To mitigate that issue, rework the initialization to avoid the
extra intel_pstate_sample() call from intel_pstate_init_cpu().
Instead, make intel_pstate_sample() return false if it has been
called with cpu->sample.time equal to zero, which will make
intel_pstate_update_util() skip the sample in that case, and
reset cpu->sample.time from intel_pstate_set_update_util_hook()
to make the algorithm start properly every time the hook is set.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The utilization update hook in the intel_pstate driver is set too
early, as it only should be set after the policy has been fully
initialized by the core. That may cause intel_pstate_update_util()
to use incorrect data and put the CPUs into incorrect P-states as
a result.
To prevent that from happening, make intel_pstate_set_policy() set
the utilization update hook instead of intel_pstate_init_cpu() so
intel_pstate_update_util() only runs when all things have been
initialized as appropriate.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Fix for an intel_pstate driver issue related to the handling of
MSR updates uncovered by the recent cpufreq rework (Rafael Wysocki).
- cpufreq core cleanups related to starting governors and frequency
synchronization during resume from system suspend and a locking
fix for cpufreq_quick_get() (Rafael Wysocki, Richard Cochran).
- acpi-cpufreq and powernv cpufreq driver updates (Jisheng Zhang,
Michael Neuling, Richard Cochran, Shilpasri Bhat).
- intel_idle driver update preventing some Skylake-H systems
from hanging during initialization by disabling deep C-states
mishandled by the platform in the problematic configurations (Len
Brown).
- Intel Xeon Phi Processor x200 support for intel_idle (Dasaratharaman
Chandramouli).
- cpuidle menu governor updates to make it always honor PM QoS
latency constraints (and prevent C1 from being used as the
fallback C-state on x86 when they are set below its exit latency)
and to restore the previous behavior to fall back to C1 if the next
timer event is set far enough in the future that was changed in 4.4
which led to an energy consumption regression (Rik van Riel, Rafael
Wysocki).
- New device ID for a future AMD UART controller in the ACPI driver
for AMD SoCs (Wang Hongcheng).
- Rockchip rk3399 support for the rockchip-io-domain adaptive voltage
scaling (AVS) driver (David Wu).
- ACPI PCI resources management fix for the handling of IO space
resources on architectures where the IO space is memory mapped
(IA64 and ARM64) broken by the introduction of common ACPI
resources parsing for PCI host bridges in 4.4 (Lorenzo Pieralisi).
- Fix for the ACPI backend of the generic device properties API
to make it parse non-device (data node only) children of an
ACPI device correctly (Irina Tirdea).
- Fixes for the handling of global suspend flags (introduced in 4.4)
during hibernation and resume from it (Lukas Wunner).
- Support for obtaining configuration information from Device Trees
in the PM clocks framework (Jon Hunter).
- ACPI _DSM helper code and devfreq framework cleanups (Colin Ian
King, Geert Uytterhoeven).
/
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)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=hUVj
-----END PGP SIGNATURE-----
Merge tag 'pm+acpi-4.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more power management and ACPI updates from Rafael Wysocki:
"The second batch of power management and ACPI updates for v4.6.
Included are fixups on top of the previous PM/ACPI pull request and
other material that didn't make into it but still should go into 4.6.
Among other things, there's a fix for an intel_pstate driver issue
uncovered by recent cpufreq changes, a workaround for a boot hang on
Skylake-H related to the handling of deep C-states by the platform and
a PCI/ACPI fix for the handling of IO port resources on non-x86
architectures plus some new device IDs and similar.
Specifics:
- Fix for an intel_pstate driver issue related to the handling of MSR
updates uncovered by the recent cpufreq rework (Rafael Wysocki).
- cpufreq core cleanups related to starting governors and frequency
synchronization during resume from system suspend and a locking fix
for cpufreq_quick_get() (Rafael Wysocki, Richard Cochran).
- acpi-cpufreq and powernv cpufreq driver updates (Jisheng Zhang,
Michael Neuling, Richard Cochran, Shilpasri Bhat).
- intel_idle driver update preventing some Skylake-H systems from
hanging during initialization by disabling deep C-states mishandled
by the platform in the problematic configurations (Len Brown).
- Intel Xeon Phi Processor x200 support for intel_idle
(Dasaratharaman Chandramouli).
- cpuidle menu governor updates to make it always honor PM QoS
latency constraints (and prevent C1 from being used as the fallback
C-state on x86 when they are set below its exit latency) and to
restore the previous behavior to fall back to C1 if the next timer
event is set far enough in the future that was changed in 4.4 which
led to an energy consumption regression (Rik van Riel, Rafael
Wysocki).
- New device ID for a future AMD UART controller in the ACPI driver
for AMD SoCs (Wang Hongcheng).
- Rockchip rk3399 support for the rockchip-io-domain adaptive voltage
scaling (AVS) driver (David Wu).
- ACPI PCI resources management fix for the handling of IO space
resources on architectures where the IO space is memory mapped
(IA64 and ARM64) broken by the introduction of common ACPI
resources parsing for PCI host bridges in 4.4 (Lorenzo Pieralisi).
- Fix for the ACPI backend of the generic device properties API to
make it parse non-device (data node only) children of an ACPI
device correctly (Irina Tirdea).
- Fixes for the handling of global suspend flags (introduced in 4.4)
during hibernation and resume from it (Lukas Wunner).
- Support for obtaining configuration information from Device Trees
in the PM clocks framework (Jon Hunter).
- ACPI _DSM helper code and devfreq framework cleanups (Colin Ian
King, Geert Uytterhoeven)"
* tag 'pm+acpi-4.6-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (23 commits)
PM / AVS: rockchip-io: add io selectors and supplies for rk3399
intel_idle: Support for Intel Xeon Phi Processor x200 Product Family
intel_idle: prevent SKL-H boot failure when C8+C9+C10 enabled
ACPI / PM: Runtime resume devices when waking from hibernate
PM / sleep: Clear pm_suspend_global_flags upon hibernate
cpufreq: governor: Always schedule work on the CPU running update
cpufreq: Always update current frequency before startig governor
cpufreq: Introduce cpufreq_update_current_freq()
cpufreq: Introduce cpufreq_start_governor()
cpufreq: powernv: Add sysfs attributes to show throttle stats
cpufreq: acpi-cpufreq: make Intel/AMD MSR access, io port access static
PCI: ACPI: IA64: fix IO port generic range check
ACPI / util: cast data to u64 before shifting to fix sign extension
cpufreq: powernv: Define per_cpu chip pointer to optimize hot-path
cpuidle: menu: Fall back to polling if next timer event is near
cpufreq: acpi-cpufreq: Clean up hot plug notifier callback
intel_pstate: Do not call wrmsrl_on_cpu() with disabled interrupts
cpufreq: Make cpufreq_quick_get() safe to call
ACPI / property: fix data node parsing in acpi_get_next_subnode()
ACPI / APD: Add device HID for future AMD UART controller
...
* pm-cpufreq:
cpufreq: governor: Always schedule work on the CPU running update
cpufreq: Always update current frequency before startig governor
cpufreq: Introduce cpufreq_update_current_freq()
cpufreq: Introduce cpufreq_start_governor()
cpufreq: powernv: Add sysfs attributes to show throttle stats
cpufreq: acpi-cpufreq: make Intel/AMD MSR access, io port access static
cpufreq: powernv: Define per_cpu chip pointer to optimize hot-path
cpufreq: acpi-cpufreq: Clean up hot plug notifier callback
intel_pstate: Do not call wrmsrl_on_cpu() with disabled interrupts
cpufreq: Make cpufreq_quick_get() safe to call
* pm-cpuidle:
intel_idle: Support for Intel Xeon Phi Processor x200 Product Family
intel_idle: prevent SKL-H boot failure when C8+C9+C10 enabled
cpuidle: menu: Fall back to polling if next timer event is near
cpuidle: menu: use high confidence factors only when considering polling
Modify dbs_irq_work() to always schedule the process-context work
on the current CPU which also ran the dbs_update_util_handler()
that the irq_work being handled came from.
This causes the entire frequency update handling (involving the
"ondemand" or "conservative" governors) to be carried out by the
CPU whose frequency is to be updated and reduces the overall amount
of inter-CPU noise related to cpufreq.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Make policy->cur match the current frequency returned by the driver's
->get() callback before starting the governor in case they went out of
sync in the meantime and drop the piece of code attempting to
resync policy->cur with the real frequency of the boot CPU from
cpufreq_resume() as it serves no purpose any more (and it's racy and
super-ugly anyway).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Move the part of cpufreq_update_policy() that obtains the current
frequency from the driver and updates policy->cur if necessary to
a separate function, cpufreq_get_current_freq().
That should not introduce functional changes and subsequent change
set will need it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Starting a governor in cpufreq always follows the same pattern
involving two calls to cpufreq_governor(), one with the event
argument set to CPUFREQ_GOV_START and one with that argument set to
CPUFREQ_GOV_LIMITS.
Introduce cpufreq_start_governor() that will carry out those two
operations and make all places where governors are started use it.
That slightly modifies the behavior of cpufreq_set_policy() which
now also will go back to the old governor if the second call to
cpufreq_governor() (the one with event equal to CPUFREQ_GOV_LIMITS)
fails, but that really is how it should work in the first place.
Also cpufreq_resume() will now pring an error message if the
CPUFREQ_GOV_LIMITS call to cpufreq_governor() fails, but that
makes it follow cpufreq_add_policy_cpu() and cpufreq_offline()
in that respect.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Create sysfs attributes to export throttle information in
/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory. The
newly added sysfs files are as follows:
1)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/turbo_stat
2)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/sub-turbo_stat
3)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/unthrottle
4)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/powercap
5)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overtemp
6)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/supply_fault
7)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overcurrent
8)/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/occ_reset
Detailed explanation of each attribute is added to
Documentation/ABI/testing/sysfs-devices-system-cpu
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
These frequency register read/write operations' implementations for the
given processor (Intel/AMD MSR access or I/O port access) are only used
internally in acpi-cpufreq, so make them static.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit 96c4726f01 "cpufreq: powernv: Remove cpu_to_chip_id() from
hot-path" introduced a 'core_to_chip_map' array to cache the chip-ids
of all cores.
Replace this with a per-CPU variable that stores the pointer to the
chip-array. This removes the linear lookup and provides a neater and
simpler solution.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Driver updates for ARM SoCs, these contain various things that touch
the drivers/ directory but got merged through arm-soc for practical
reasons:
- Rockchip rk3368 gains power domain support
- Small updates for the ARM spmi driver
- The Atmel PMC driver saw a larger rework, touching both
arch/arm/mach-at91 and drivers/clk/at91
- All reset controller driver changes alway get merged through
arm-soc, though this time the largest change is the addition
of a MIPS pistachio reset driver
- One bugfix for the NXP (formerly Freescale) i.MX weim bus driver
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=HS4G
-----END PGP SIGNATURE-----
Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC driver updates from Arnd Bergmann:
"Driver updates for ARM SoCs, these contain various things that touch
the drivers/ directory but got merged through arm-soc for practical
reasons:
- Rockchip rk3368 gains power domain support
- Small updates for the ARM spmi driver
- The Atmel PMC driver saw a larger rework, touching both
arch/arm/mach-at91 and drivers/clk/at91
- All reset controller driver changes alway get merged through
arm-soc, though this time the largest change is the addition of a
MIPS pistachio reset driver
- One bugfix for the NXP (formerly Freescale) i.MX weim bus driver"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (43 commits)
bus: imx-weim: Take the 'status' property value into account
clk: at91: remove useless includes
clk: at91: pmc: remove useless capacities handling
clk: at91: pmc: drop at91_pmc_base
usb: gadget: atmel: access the PMC using regmap
ARM: at91: remove useless includes and function prototypes
ARM: at91: pm: move idle functions to pm.c
ARM: at91: pm: find and remap the pmc
ARM: at91: pm: simply call at91_pm_init
clk: at91: pmc: move pmc structures to C file
clk: at91: pmc: merge at91_pmc_init in atmel_pmc_probe
clk: at91: remove IRQ handling and use polling
clk: at91: make use of syscon/regmap internally
clk: at91: make use of syscon to share PMC registers in several drivers
hwmon: (scpi) add energy meter support
firmware: arm_scpi: add support for 64-bit sensor values
firmware: arm_scpi: decrease Tx timeout to 20ms
firmware: arm_scpi: fix send_message and sensor_get_value for big-endian
reset: sti: Make reset_control_ops const
reset: zynq: Make reset_control_ops const
...
Newly added support for additional SoCs:
- Axis Artpec-6 SoC family
- Allwinner A83T SoC
- Mediatek MT7623
- NXP i.MX6QP SoC
- ST Microelectronics stm32f469 microcontroller
New features:
- SMP support for Mediatek mt2701
- Big-endian support for NXP i.MX
- DaVinci now uses the new DMA engine dma_slave_map
- OMAP now uses the new DMA engine dma_slave_map
- earlyprintk support for palmchip uart on mach-tango
- delay timer support for orion
Other:
- Exynos PMU driver moved out to drivers/soc/
- Various smaller updates for Renesas, Xilinx, PXA, AT91, OMAP, uniphier
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQIVAwUAVu68DGCrR//JCVInAQIHVQ//Wblms+NKj3aKh6m2Sscs/YkSbFaQ4sY2
rNyfxLIYsLXkth1kbdHRFSMyL68Ym+xutErgw/3HQPB2D1YtYJE3VJ/y8AU92SU3
oHyQIty+atB8d8zBbtlkWmat94NIfYf0I8PQETreGb1LMaJqAf0mDEDAyorTLZcZ
UtQ817Ihn7urqwdTJpTO58V41RmY/vflbHI5T6bIjUJn6fF1e/7+VqtMIfq5sjJ6
0EPEQdu8s5AJ7gcGlGi9I5gAtSnWSA/9phAxul9P8/HrMpUWIxreSEAy8FY7W14F
4TON3sQrnw7nyA72U80KGIXhgLy7SbEmHcSqyy4YJK3ycdk6VYk0CBO7nWVYAiD1
knLisOH6jwe0LIj9WXiRR+Y2Q53pXN8SF77pLDahSnvuShnYEjEH5uELHtxe7Vxh
gn+NH1rDkRTgdYgt4RWlVyUoLkddQWzLb1m4QyQlvxtTR25cJJayXdVX2MRrNPF5
c1zRa9HH+b8LJQIMdWfo/NoHhHtftkkGGsqHAAaypZqdpyk0j2HpJYk5ecPR4f5C
/8o/h/5xOI9gEzp/DVYSZ1VAvRqBQGIDfKBXWq6GuoZaF0aN8ISe5IxFn5Yx2F46
fNaxqiNpWmyywl8D+tSWPFK6aE21AXKGi5zIzexZZqy283aDjlUPI+tgF2GKIuKP
3ayYTDeBpLI=
=ynNj
-----END PGP SIGNATURE-----
Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC platform updates from Arnd Bergmann:
"Newly added support for additional SoCs:
- Axis Artpec-6 SoC family
- Allwinner A83T SoC
- Mediatek MT7623
- NXP i.MX6QP SoC
- ST Microelectronics stm32f469 microcontroller
New features:
- SMP support for Mediatek mt2701
- Big-endian support for NXP i.MX
- DaVinci now uses the new DMA engine dma_slave_map
- OMAP now uses the new DMA engine dma_slave_map
- earlyprintk support for palmchip uart on mach-tango
- delay timer support for orion
Other:
- Exynos PMU driver moved out to drivers/soc/
- Various smaller updates for Renesas, Xilinx, PXA, AT91, OMAP,
uniphier"
* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (83 commits)
ARM: uniphier: rework SMP code to support new System Bus binding
ARM: uniphier: add missing of_node_put()
ARM: at91: avoid defining CONFIG_* symbols in source code
ARM: DRA7: hwmod: Add data for eDMA tpcc, tptc0, tptc1
ARM: imx: Make reset_control_ops const
ARM: imx: Do L2 errata only if the L2 cache isn't enabled
ARM: imx: select ARM_CPU_SUSPEND only for imx6
dmaengine: pxa_dma: fix the maximum requestor line
ARM: alpine: select the Alpine MSI controller driver
ARM: pxa: add the number of DMA requestor lines
dmaengine: mmp-pdma: add number of requestors
dma: mmp_pdma: Add the #dma-requests DT property documentation
ARM: OMAP2+: Add rtc hwmod configuration for ti81xx
ARM: s3c24xx: Avoid warning for inb/outb
ARM: zynq: Move early printk virtual address to vmalloc area
ARM: DRA7: hwmod: Add custom reset handler for PCIeSS
ARM: SAMSUNG: Remove unused register offset definition
ARM: EXYNOS: Cleanup header files inclusion
drivers: soc: samsung: Enable COMPILE_TEST
MAINTAINERS: Add maintainers entry for drivers/soc/samsung
...
This driver has two issues. First, it tries to fiddle with the hot
plugged CPU's MSR on the UP_PREPARE event, at a time when the CPU is
not yet online. Second, the driver sets the "boost-disable" bit for a
CPU when going down, but does not clear the bit again if the CPU comes
up again due to DOWN_FAILED.
This patch fixes the issues by changing the driver to react to the
ONLINE/DOWN_FAILED events instead of UP_PREPARE. As an added benefit,
the driver also becomes symmetric with respect to the hot plug
mechanism.
Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
After commit a4675fbc4a (cpufreq: intel_pstate: Replace timers with
utilization update callbacks) wrmsrl_on_cpu() cannot be called in the
intel_pstate_adjust_busy_pstate() path as that is executed with
disabled interrupts. However, atom_set_pstate() called from there
via intel_pstate_set_pstate() uses wrmsrl_on_cpu() to update the
IA32_PERF_CTL MSR which triggers the WARN_ON_ONCE() in
smp_call_function_single().
The reason why wrmsrl_on_cpu() is used by atom_set_pstate() is
because intel_pstate_set_pstate() calling it is also invoked during
the initialization and cleanup of the driver and in those cases it is
not guaranteed to be run on the CPU that is being updated. However,
in the case when intel_pstate_set_pstate() is called by
intel_pstate_adjust_busy_pstate(), wrmsrl() can be used to update
the register safely. Moreover, intel_pstate_set_pstate() already
contains code that only is executed if the function is called by
intel_pstate_adjust_busy_pstate() and there is a special argument
passed to it because of that.
To fix the problem at hand, rearrange the code taking the above
observations into account.
First, replace the ->set() callback in struct pstate_funcs with a
->get_val() one that will return the value to be written to the
IA32_PERF_CTL MSR without updating the register.
Second, split intel_pstate_set_pstate() into two functions,
intel_pstate_update_pstate() to be called by
intel_pstate_adjust_busy_pstate() that will contain all of the
intel_pstate_set_pstate() code which only needs to be executed in
that case and will use wrmsrl() to update the MSR (after obtaining
the value to write to it from the ->get_val() callback), and
intel_pstate_set_min_pstate() to be invoked during the
initialization and cleanup that will set the P-state to the
minimum one and will update the MSR using wrmsrl_on_cpu().
Finally, move the code shared between intel_pstate_update_pstate()
and intel_pstate_set_min_pstate() to a new static inline function
intel_pstate_record_pstate() and make them both call it.
Of course, that unifies the handling of the IA32_PERF_CTL MSR writes
between Atom and Core.
Fixes: a4675fbc4a (cpufreq: intel_pstate: Replace timers with utilization update callbacks)
Reported-and-tested-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The function, cpufreq_quick_get, accesses the global 'cpufreq_driver' and
its fields without taking the associated lock, cpufreq_driver_lock.
Without the locking, nothing guarantees that 'cpufreq_driver' remains
consistent during the call. This patch fixes the issue by taking the lock
before accessing the data structure.
Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-cpufreq: (94 commits)
intel_pstate: Do not skip samples partially
intel_pstate: Remove freq calculation from intel_pstate_calc_busy()
intel_pstate: Move intel_pstate_calc_busy() into get_target_pstate_use_performance()
intel_pstate: Optimize calculation for max/min_perf_adj
intel_pstate: Remove extra conversions in pid calculation
cpufreq: Move scheduler-related code to the sched directory
Revert "cpufreq: postfix policy directory with the first CPU in related_cpus"
cpufreq: Reduce cpufreq_update_util() overhead a bit
cpufreq: Select IRQ_WORK if CPU_FREQ_GOV_COMMON is set
cpufreq: Remove 'policy->governor_enabled'
cpufreq: Rename __cpufreq_governor() to cpufreq_governor()
cpufreq: Relocate handle_update() to kill its declaration
cpufreq: governor: Drop unnecessary checks from show() and store()
cpufreq: governor: Fix race in dbs_update_util_handler()
cpufreq: governor: Make gov_set_update_util() static
cpufreq: governor: Narrow down the dbs_data_mutex coverage
cpufreq: governor: Make dbs_data_mutex static
cpufreq: governor: Relocate definitions of tuners structures
cpufreq: governor: Move per-CPU data to the common code
cpufreq: governor: Make governor private data per-policy
...
If the current value of MPERF or the current value of TSC is the
same as the previous one, respectively, intel_pstate_sample() bails
out early and skips the sample.
However, intel_pstate_adjust_busy_pstate() is still called in that
case which is not correct, so modify intel_pstate_sample() to
return a bool value indicating whether or not the sample has been
taken and use it to decide whether or not to call
intel_pstate_adjust_busy_pstate().
While at it, remove redundant parentheses from the MPERF/TSC
check in intel_pstate_sample().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Use a helper function to compute the average pstate and call it only
where it is needed (only when tracing or in intel_pstate_get).
Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpu_load algorithm doesn't need to invoke intel_pstate_calc_busy(),
so move that call from intel_pstate_sample() to
get_target_pstate_use_performance().
Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
mul_fp(int_tofp(A), B) expands to:
((A << FRAC_BITS) * B) >> FRAC_BITS, so the same result can be obtained
via simple multiplication A * B. Apply this observation to
max_perf * limits->max_perf and max_perf * limits->min_perf in
intel_pstate_get_min_max()."
Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
pid->setpoint and pid->deadband can be initialized in fixed point, so we
can avoid the int_tofp in pid_calc.
Signed-off-by: Philippe Longepe <philippe.longepe@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Create cpufreq.c under kernel/sched/ and move the cpufreq code
related to the scheduler to that file and to sched.h.
Redefine cpufreq_update_util() as a static inline function to avoid
function calls at its call sites in the scheduler code (as suggested
by Peter Zijlstra).
Also move the definition of struct update_util_data and declaration
of cpufreq_set_update_util_data() from include/linux/cpufreq.h to
include/linux/sched.h.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Revert commit 3510fac454 (cpufreq: postfix policy directory with the
first CPU in related_cpus).
Earlier, the policy->kobj was added to the kobject core, before ->init()
callback was called for the cpufreq drivers. Which allowed those drivers
to add or remove, driver dependent, sysfs files/directories to the same
kobj from their ->init() and ->exit() callbacks.
That isn't possible anymore after commit 3510fac454.
Now, there is no other clean alternative that people can adopt.
Its better to revert the earlier commit to allow cpufreq drivers to
create/remove sysfs files from ->init() and ->exit() callbacks.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Use the observation that cpufreq_update_util() is only called
by the scheduler with rq->lock held, so the callers of
cpufreq_set_update_util_data() can use synchronize_sched()
instead of synchronize_rcu() to wait for cpufreq_update_util()
to complete. Moreover, if they are updated to do that,
rcu_read_(un)lock() calls in cpufreq_update_util() might be
replaced with rcu_read_(un)lock_sched(), respectively, but
those aren't really necessary, because the scheduler calls
that function from RCU-sched read-side critical sections
already.
In addition to that, if cpufreq_set_update_util_data() checks
the func field in the struct update_util_data before setting
the per-CPU pointer to it, the data->func check may be dropped
from cpufreq_update_util() as well.
Make the above changes to reduce the overhead from
cpufreq_update_util() in the scheduler paths invoking it
and to make the cleanup after removing its callbacks less
heavy-weight somewhat.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Commit 0eb463be3436 (cpufreq: governor: Replace timers with utilization
update callbacks) made CPU_FREQ select IRQ_WORK, but that's not
necessary, as it is sufficient for IRQ_WORK to be selected by
CPU_FREQ_GOV_COMMON, so modify the cpufreq Kconfig to that effect.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The entire sequence of events (like INIT/START or STOP/EXIT) for which
cpufreq_governor() is called, is guaranteed to be protected by
policy->rwsem now.
The additional checks that were added earlier (as we were forced to drop
policy->rwsem before calling cpufreq_governor() for EXIT event), aren't
required anymore.
Over that, they weren't sufficient really. They just take care of
START/STOP events, but not INIT/EXIT and the state machine was never
maintained properly by them.
Kill the unnecessary checks and policy->governor_enabled field.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The __ at the beginning of the routine aren't really necessary at all.
Rename it to cpufreq_governor() instead.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
handle_update() is declared at the top of the file as its user appear
before its definition. Relocate the routine to get rid of this.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The show() and store() routines in the cpufreq-governor core don't need
to check if the struct governor_attr they want to use really provides
the callbacks they need as expected (if that's not the case, it means a
bug in the code anyway), so change them to avoid doing that.
Also change the error value to -EBUSY, if the governor is getting
removed and we aren't allowed to store any more changes.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There is a scenario that may lead to undesired results in
dbs_update_util_handler(). Namely, if two CPUs sharing a policy
enter the funtion at the same time, pass the sample delay check
and then one of them is stalled until dbs_work_handler() (queued
up by the other CPU) clears the work counter, it may update the
work counter and queue up another work item prematurely.
To prevent that from happening, use the observation that the CPU
queuing up a work item in dbs_update_util_handler() updates the
last sample time. This means that if another CPU was stalling after
passing the sample delay check and now successfully updated the work
counter as a result of the race described above, it will see the new
value of the last sample time which is different from what it used in
the sample delay check before. If that happens, the sample delay
check passed previously is not valid any more, so the CPU should not
continue.
Fixes: f17cbb53783c (cpufreq: governor: Avoid atomic operations in hot paths)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The gov_set_update_util() routine is only used internally by the
common governor code and it doesn't need to be exported, so make
it static.
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Since cpufreq_governor_dbs() is now always called with policy->rwsem
held, it cannot be executed twice in parallel for the same policy.
Thus it is not necessary to hold dbs_data_mutex around the invocations
of cpufreq_governor_start/stop/limits() from it as those functions
never modify any data that can be shared between different policies.
However, cpufreq_governor_dbs() may be executed twice in parallal
for different policies using the same gov->gdbs_data object and
dbs_data_mutex is still necessary to protect that object against
concurrent updates.
For this reason, narrow down the dbs_data_mutex locking to
cpufreq_governor_init/exit() where it is needed and rename the
mutex to gov_dbs_data_mutex to reflect its purpose.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
That mutex is only used by cpufreq_governor_dbs() and it doesn't
need to be exported to modules, so make it static and drop the
export incantation.
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Move the definitions of struct od_dbs_tuners and struct cs_dbs_tuners
from the common governor header to the ondemand and conservative
governor code, respectively, as they don't need to be in the common
header any more.
No functional changes.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
After previous changes there is only one piece of code in the
ondemand governor making references to per-CPU data structures,
but it can be easily modified to avoid doing that, so modify it
accordingly and move the definition of per-CPU data used by the
ondemand and conservative governors to the common code. Next,
change that code to access the per-CPU data structures directly
rather than via a governor callback.
This causes the ->get_cpu_cdbs governor callback to become
unnecessary, so drop it along with the macro and function
definitions related to it.
Finally, drop the definitions of struct od_cpu_dbs_info_s and
struct cs_cpu_dbs_info_s that aren't necessary any more.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Some fields in struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s
are only used for a limited set of CPUs. Namely, if a policy is
shared between multiple CPUs, those fields will only be used for one
of them (policy->cpu). This means that they really are per-policy
rather than per-CPU and holding room for them in per-CPU data
structures is generally wasteful. Also moving those fields into
per-policy data structures will allow some significant simplifications
to be made going forward.
For this reason, introduce struct cs_policy_dbs_info and
struct od_policy_dbs_info to hold those fields. Define each of the
new structures as an extension of struct policy_dbs_info (such that
struct policy_dbs_info is embedded in each of them) and introduce
new ->alloc and ->free governor callbacks to allocate and free
those structures, respectively, such that ->alloc() will return
a pointer to the struct policy_dbs_info embedded in the allocated
data structure and ->free() will take that pointer as its argument.
With that, modify the code accessing the data fields in question
in per-CPU data objects to look for them in the new structures
via the struct policy_dbs_info pointer available to it and drop
them from struct od_cpu_dbs_info_s and struct cs_cpu_dbs_info_s.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The ondemand_powersave_bias_init() function used for resetting data
fields related to the powersave bias tunable of the ondemand governor
works by walking all of the online CPUs in the system and updating the
od_cpu_dbs_info_s structures for all of them.
However, if governor tunables are per policy, the update should not
touch the CPUs that are not associated with the given dbs_data.
Moreover, since the data fields in question are only ever used for
policy->cpu in each policy governed by ondemand, the update can be
limited to those specific CPUs.
Rework the code to take the above observations into account.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The ->store() callbacks of some tunable sysfs attributes of the
ondemand and conservative governors trigger immediate updates of
the CPU load information for all CPUs "governed" by the given
dbs_data by walking the cpu_dbs_info structures for all online
CPUs in the system and updating them.
This is questionable for two reasons. First, it may lead to a lot of
extra overhead on a system with many CPUs if the given dbs_data is
only associated with a few of them. Second, if governor tunables are
per-policy, the CPUs associated with the other sets of governor
tunables should not be updated.
To address this issue, use the observation that in all of the places
in question the update operation may be carried out in the same way
(because all of the tunables involved are now located in struct
dbs_data and readily available to the common code) and make the
code in those places invoke the same (new) helper function that
will carry out the update correctly.
That new function always checks the ignore_nice_load tunable value
and updates the CPUs' prev_cpu_nice data fields if that's set, which
wasn't done by the original code in store_io_is_busy(), but it
should have been done in there too.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
The ->powersave_bias_init_cpu callback in struct od_ops is only used
in one place and that invocation may be replaced with a direct call
to the function pointed to by that callback, so change the code
accordingly and drop the callback.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
