Commit 143e1e28cb (sched: Rework sched_domain topology definition)
introduced a number of functions with a return value of 'const int'.
gcc doesn't know what to do with that and, if the kernel is compiled
with W=1, complains with the following warnings whenever sched.h
is included.
include/linux/sched.h:875:25: warning: type qualifiers ignored on function return type
include/linux/sched.h:882:25: warning: type qualifiers ignored on function return type
include/linux/sched.h:889:25: warning: type qualifiers ignored on function return type
include/linux/sched.h:1002:21: warning: type qualifiers ignored on function return type
Commits fb2aa855 (sched, ARM: Create a dedicated scheduler topology table)
and 607b45e9a (sched, powerpc: Create a dedicated topology table) introduce
the same warning in the arm and powerpc code.
Drop 'const' from the function declarations to fix the problem.
The fix for all three patches has to be applied together to avoid
compilation failures for the affected architectures.
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1403658329-13196-1-git-send-email-linux@roeck-us.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull more scheduler updates from Ingo Molnar:
"Second round of scheduler changes:
- try-to-wakeup and IPI reduction speedups, from Andy Lutomirski
- continued power scheduling cleanups and refactorings, from Nicolas
Pitre
- misc fixes and enhancements"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Delete extraneous extern for to_ratio()
sched/idle: Optimize try-to-wake-up IPI
sched/idle: Simplify wake_up_idle_cpu()
sched/idle: Clear polling before descheduling the idle thread
sched, trace: Add a tracepoint for IPI-less remote wakeups
cpuidle: Set polling in poll_idle
sched: Remove redundant assignment to "rt_rq" in update_curr_rt(...)
sched: Rename capacity related flags
sched: Final power vs. capacity cleanups
sched: Remove remaining dubious usage of "power"
sched: Let 'struct sched_group_power' care about CPU capacity
sched/fair: Disambiguate existing/remaining "capacity" usage
sched/fair: Change "has_capacity" to "has_free_capacity"
sched/fair: Remove "power" from 'struct numa_stats'
sched: Fix signedness bug in yield_to()
sched/fair: Use time_after() in record_wakee()
sched/balancing: Reduce the rate of needless idle load balancing
sched/fair: Fix unlocked reads of some cfs_b->quota/period
Pull ARM updates from Russell King:
- Major clean-up of the L2 cache support code. The existing mess was
becoming rather unmaintainable through all the additions that others
have done over time. This turns it into a much nicer structure, and
implements a few performance improvements as well.
- Clean up some of the CP15 control register tweaks for alignment
support, moving some code and data into alignment.c
- DMA properties for ARM, from Santosh and reviewed by DT people. This
adds DT properties to specify bus translations we can't discover
automatically, and to indicate whether devices are coherent.
- Hibernation support for ARM
- Make ftrace work with read-only text in modules
- add suspend support for PJ4B CPUs
- rework interrupt masking for undefined instruction handling, which
allows us to enable interrupts earlier in the handling of these
exceptions.
- support for big endian page tables
- fix stacktrace support to exclude stacktrace functions from the
trace, and add save_stack_trace_regs() implementation so that kprobes
can record stack traces.
- Add support for the Cortex-A17 CPU.
- Remove last vestiges of ARM710 support.
- Removal of ARM "meminfo" structure, finally converting us solely to
memblock to handle the early memory initialisation.
* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (142 commits)
ARM: ensure C page table setup code follows assembly code (part II)
ARM: ensure C page table setup code follows assembly code
ARM: consolidate last remaining open-coded alignment trap enable
ARM: remove global cr_no_alignment
ARM: remove CPU_CP15 conditional from alignment.c
ARM: remove unused adjust_cr() function
ARM: move "noalign" command line option to alignment.c
ARM: provide common method to clear bits in CPU control register
ARM: 8025/1: Get rid of meminfo
ARM: 8060/1: mm: allow sub-architectures to override PCI I/O memory type
ARM: 8066/1: correction for ARM patch 8031/2
ARM: 8049/1: ftrace/add save_stack_trace_regs() implementation
ARM: 8065/1: remove last use of CONFIG_CPU_ARM710
ARM: 8062/1: Modify ldrt fixup handler to re-execute the userspace instruction
ARM: 8047/1: rwsem: use asm-generic rwsem implementation
ARM: l2c: trial at enabling some Cortex-A9 optimisations
ARM: l2c: add warnings for stuff modifying aux_ctrl register values
ARM: l2c: print a warning with L2C-310 caches if the cache size is modified
ARM: l2c: remove old .set_debug method
ARM: l2c: kill L2X0_AUX_CTRL_MASK before anyone else makes use of this
...
These symbols are only referenced in this source file so can be made
static, and the efficiency table is constant data so can be declared as
such. This avoids polluting the global namespace and fixes warnings
from sparse.
The function arch_scale_freq_power() is still not prototyped or static,
this is a separate issue as this is overriding a weak symbol from the
scheduler which neglects to provide a prototype.
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Currently the topology code computes cpu capacity and stores it in
the list along with hwid(which is MPIDR) as it parses the CPU nodes
in the device tree. This is required as it needs to be mapped to the
logical CPU later.
Since the CPU device nodes can be retrieved in the logical ordering
using DT/OF helpers, its possible to store cpu_capacity also in logical
ordering and avoid storing hwid for each entry.
This patch removes hwid by making use of of_get_cpu_node.
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
The cpu_topology symbol is required by any driver using the topology
interfaces, which leads to a couple of build errors:
ERROR: "cpu_topology" [drivers/net/ethernet/sfc/sfc.ko] undefined!
ERROR: "cpu_topology" [drivers/cpufreq/arm_big_little.ko] undefined!
ERROR: "cpu_topology" [drivers/block/mtip32xx/mtip32xx.ko] undefined!
The obvious solution is to export this symbol.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch updates the topology initialization code to use the newly
defined accessors to retrieve the MPIDR affinity levels.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Kernel subsystems other than the topology layer need the MPIDR
mask definitions to access the MPIDR without relying on hardcoded
masks. This patch moves the MPIDR register masks definition to
a header file and defines a macro to simplify access to MPIDR bit fields
representing affinity levels.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Get rid of this warning..
arch/arm/kernel/built-in.o(.text+0xac78): Section mismatch in reference
from the function init_cpu_topology() to the function
.init.text:parse_dt_topology()
The function init_cpu_topology() references
the function __init parse_dt_topology().
This is often because init_cpu_topology lacks a __init
annotation or the annotation of parse_dt_topology is wrong.
Signed-off-by: Venkatraman S <svenkatr@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Use cpu compatibility field and clock-frequency field of DT to
estimate the capacity of each core of the system and to update
the cpu_power field accordingly.
This patch enables to put more running tasks on big cores than
on LITTLE ones. But this patch doesn't ensure that long running
tasks will run on big cores and short ones on LITTLE cores.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
kernel/sched.c:7354:2: warning: initialization from incompatible pointer type
Align cpu_coregroup_mask prototype interface with sched_domain_mask_f typedef
use int cpu instead of unsigned int cpu
Cc: <stable@vger.kernel.org>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The affinity between ARM processors is defined in the MPIDR register.
We can identify which processors are in the same cluster,
and which ones have performance interdependency. We can define the
cpu topology of ARM platform, that is then used by sched_mc and sched_smt.
The default state of sched_mc and sched_smt config is disable.
When enabled, the behavior of the scheduler can be modified with
sched_mc_power_savings and sched_smt_power_savings sysfs interfaces.
Changes since v4 :
* Remove unnecessary parentheses and blank lines
Changes since v3 :
* Update the format of printk message
* Remove blank line
Changes since v2 :
* Update the commit message and some comments
Changes since v1 :
* Update the commit message
* Add read_cpuid_mpidr in arch/arm/include/asm/cputype.h
* Modify header of arch/arm/kernel/topology.c
* Modify tests and manipulation of MPIDR's bitfields
* Modify the place and dependancy of the config
* Modify Noop functions
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
