linux/kernel/irq/Kconfig

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# Select this to activate the generic irq options below
config HAVE_GENERIC_HARDIRQS
bool
if HAVE_GENERIC_HARDIRQS
menu "IRQ subsystem"
#
# Interrupt subsystem related configuration options
#
config GENERIC_HARDIRQS
def_bool y
# Options selectable by the architecture code
# Make sparse irq Kconfig switch below available
config MAY_HAVE_SPARSE_IRQ
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
# Support for delayed migration from interrupt context
config GENERIC_PENDING_IRQ
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
# Generic irq_domain hw <--> linux irq number translation
config IRQ_DOMAIN
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 "virq_mapping".
If you don't know what this means you don't need it.
# Support forced irq threading
genirq: Provide forced interrupt threading Add a commandline parameter "threadirqs" which forces all interrupts except those marked IRQF_NO_THREAD to run threaded. That's mostly a debug option to allow retrieving better debug data from crashing interrupt handlers. If "threadirqs" is not enabled on the kernel command line, then there is no impact in the interrupt hotpath. Architecture code needs to select CONFIG_IRQ_FORCED_THREADING after marking the interrupts which cant be threaded IRQF_NO_THREAD. All interrupts which have IRQF_TIMER set are implict marked IRQF_NO_THREAD. Also all PER_CPU interrupts are excluded. Forced threading hard interrupts also forces all soft interrupt handling into thread context. When enabled it might slow down things a bit, but for debugging problems in interrupt code it's a reasonable penalty as it does not immediately crash and burn the machine when an interrupt handler is buggy. Some test results on a Core2Duo machine: Cache cold run of: # time git grep irq_desc non-threaded threaded real 1m18.741s 1m19.061s user 0m1.874s 0m1.757s sys 0m5.843s 0m5.427s # iperf -c server non-threaded [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 933 Mbits/sec threaded [ 3] 0.0-10.0 sec 1.09 GBytes 939 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 934 Mbits/sec [ 3] 0.0-10.0 sec 1.09 GBytes 937 Mbits/sec Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <20110223234956.772668648@linutronix.de>
2011-02-23 23:52:23 +00:00
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.
endmenu
endif