From 4b9091e1c1948dea3b0b097496f308ede897d665 Mon Sep 17 00:00:00 2001 From: Song Chen Date: Thu, 28 Jan 2021 09:35:13 +0800 Subject: kernel: trace: preemptirq_delay_test: add cpu affinity The kernel thread executing test can run on any cpu, which might be different cpu latency tracer is running on, as a result, the big latency caused by preemptirq delay test can't be detected. Therefore, the argument cpu_affinity is added to be passed to test, ensure it's running on the same cpu with latency tracer. e.g. cyclictest -p 90 -m -c 0 -i 1000 -a 3 modprobe preemptirq_delay_test test_mode=preempt delay=500 \ burst_size=3 cpu_affinity=3 Link: https://lkml.kernel.org/r/1611797713-20965-1-git-send-email-chensong_2000@189.cn Signed-off-by: Song Chen Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/Kconfig | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'kernel/trace/Kconfig') diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 4f976f8d9a38..799dbcfe65ad 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -886,6 +886,10 @@ config PREEMPTIRQ_DELAY_TEST irq-disabled critical sections for 500us: modprobe preemptirq_delay_test test_mode=irq delay=500 burst_size=3 + What's more, if you want to attach the test on the cpu which the latency + tracer is running on, specify cpu_affinity=cpu_num at the end of the + command. + If unsure, say N config SYNTH_EVENT_GEN_TEST -- cgit v1.2.3-59-g8ed1b