linux_dsm_epyc7002/kernel/irq/Kconfig
Daniel Lezcano b2d3d61adb genirq/timings: Add infrastructure to track the interrupt timings
The interrupt framework gives a lot of information about each interrupt. It
does not keep track of when those interrupts occur though, which is a
prerequisite for estimating the next interrupt arrival for power management
purposes.

Add a mechanism to record the timestamp for each interrupt occurrences in a
per-CPU circular buffer to help with the prediction of the next occurrence
using a statistical model.

Each CPU can store up to IRQ_TIMINGS_SIZE events <irq, timestamp>, the
current value of IRQ_TIMINGS_SIZE is 32.

Each event is encoded into a single u64, where the high 48 bits are used
for the timestamp and the low 16 bits are for the irq number.

A static key is introduced so when the irq prediction is switched off at
runtime, the overhead is near to zero.

It results in most of the code in internals.h for inline reasons and a very
few in the new file timings.c. The latter will contain more in the next patch
which will provide the statistical model for the next event prediction.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: http://lkml.kernel.org/r/1498227072-5980-1-git-send-email-daniel.lezcano@linaro.org
2017-06-24 11:44:11 +02:00

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menu "IRQ subsystem"
# Options selectable by the architecture code
# Make sparse irq Kconfig switch below available
config MAY_HAVE_SPARSE_IRQ
bool
# Legacy support, required for itanic
config GENERIC_IRQ_LEGACY
bool
# Enable the generic irq autoprobe mechanism
config GENERIC_IRQ_PROBE
bool
# Use the generic /proc/interrupts implementation
config GENERIC_IRQ_SHOW
bool
# Print level/edge extra information
config GENERIC_IRQ_SHOW_LEVEL
bool
# Supports effective affinity mask
config GENERIC_IRQ_EFFECTIVE_AFF_MASK
bool
# Facility to allocate a hardware interrupt. This is legacy support
# and should not be used in new code. Use irq domains instead.
config GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
bool
# Support for delayed migration from interrupt context
config GENERIC_PENDING_IRQ
bool
# Support for generic irq migrating off cpu before the cpu is offline.
config GENERIC_IRQ_MIGRATION
bool
# Alpha specific irq affinity mechanism
config AUTO_IRQ_AFFINITY
bool
# Tasklet based software resend for pending interrupts on enable_irq()
config HARDIRQS_SW_RESEND
bool
# Preflow handler support for fasteoi (sparc64)
config IRQ_PREFLOW_FASTEOI
bool
# Edge style eoi based handler (cell)
config IRQ_EDGE_EOI_HANDLER
bool
# Generic configurable interrupt chip implementation
config GENERIC_IRQ_CHIP
bool
select IRQ_DOMAIN
# Generic irq_domain hw <--> linux irq number translation
config IRQ_DOMAIN
bool
# Support for hierarchical irq domains
config IRQ_DOMAIN_HIERARCHY
bool
select IRQ_DOMAIN
# Generic IRQ IPI support
config GENERIC_IRQ_IPI
bool
# Generic MSI interrupt support
config GENERIC_MSI_IRQ
bool
# Generic MSI hierarchical interrupt domain support
config GENERIC_MSI_IRQ_DOMAIN
bool
select IRQ_DOMAIN_HIERARCHY
select GENERIC_MSI_IRQ
config HANDLE_DOMAIN_IRQ
bool
config IRQ_TIMINGS
bool
config IRQ_DOMAIN_DEBUG
bool "Expose hardware/virtual IRQ mapping via debugfs"
depends on IRQ_DOMAIN && DEBUG_FS
help
This option will show the mapping relationship between hardware irq
numbers and Linux irq numbers. The mapping is exposed via debugfs
in the file "irq_domain_mapping".
If you don't know what this means you don't need it.
# Support forced irq threading
config IRQ_FORCED_THREADING
bool
config SPARSE_IRQ
bool "Support sparse irq numbering" if MAY_HAVE_SPARSE_IRQ
---help---
Sparse irq numbering is useful for distro kernels that want
to define a high CONFIG_NR_CPUS value but still want to have
low kernel memory footprint on smaller machines.
( Sparse irqs can also be beneficial on NUMA boxes, as they spread
out the interrupt descriptors in a more NUMA-friendly way. )
If you don't know what to do here, say N.
config GENERIC_IRQ_DEBUGFS
bool "Expose irq internals in debugfs"
depends on DEBUG_FS
default n
---help---
Exposes internal state information through debugfs. Mostly for
developers and debugging of hard to diagnose interrupt problems.
If you don't know what to do here, say N.
endmenu