summaryrefslogtreecommitdiff
path: root/kernel/trace/Kconfig
diff options
context:
space:
mode:
authorMel Gorman <mgorman@techsingularity.net>2020-04-09 13:40:34 +0300
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2020-06-06 03:08:26 +0300
commit388d8bdb87e01bcea6d0b2bf797b5f6d7b2401fb (patch)
tree089b5a342c116668658ef3ea8c5f109840300b2a /kernel/trace/Kconfig
parentdaceabf1b494c9e40a93fcc323b1258f557f65a1 (diff)
downloadlinux-388d8bdb87e01bcea6d0b2bf797b5f6d7b2401fb.tar.xz
tracing: Remove obsolete PREEMPTIRQ_EVENTS kconfig option
The PREEMPTIRQ_EVENTS option is unused after commit c3bc8fd637a9 ("tracing: Centralize preemptirq tracepoints and unify their usage"). Remove it. Note that this option is hazardous as it stands. It enables TRACE_IRQFLAGS event on non-preempt configurations without the irqsoff tracer enabled. TRACE_IRQFLAGS as it stands incurs significant overhead on each IRQ entry/exit. This is because trace_hardirqs_[on|off] does all the per-cpu manipulations and NMI checks even if tracing is completely disabled for some insane reason. For example, netperf running UDP_STREAM on localhost incurs a 4-6% performance penalty without any tracing if IRQFLAGS is set. It can be put behind a static brach but even the function entry/exit costs a little bit. Link: https://lkml.kernel.org/r/20200409104034.GJ3818@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/Kconfig')
-rw-r--r--kernel/trace/Kconfig9
1 files changed, 0 insertions, 9 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 75407d5dc83a..0c82ac2c5688 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -258,15 +258,6 @@ config TRACE_PREEMPT_TOGGLE
Enables hooks which will be called when preemption is first disabled,
and last enabled.
-config PREEMPTIRQ_EVENTS
- bool "Enable trace events for preempt and irq disable/enable"
- select TRACE_IRQFLAGS
- select TRACE_PREEMPT_TOGGLE if PREEMPTION
- select GENERIC_TRACER
- default n
- help
- Enable tracing of disable and enable events for preemption and irqs.
-
config IRQSOFF_TRACER
bool "Interrupts-off Latency Tracer"
default n