tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc

Source file repositories/reference/linux-study-clean/tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/ftrace/test.d/ftrace/func_hotplug.tc
Extension
.tc
Size
874 bytes
Lines
43
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: tools
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

nproc() {
    ls -d /sys/devices/system/cpu/cpu[0-9]* | wc -l
  }
fi

NP=`nproc`

if [ $NP -eq 1 ] ;then
  echo "We cannot test cpu hotplug in UP environment"
  exit_unresolved
fi

# Find online cpu
for i in /sys/devices/system/cpu/cpu[1-9]*; do
	if [ -f $i/online ] && [ "$(cat $i/online)" = "1" ]; then
		cpu=$i
		break
	fi
done

if [ -z "$cpu" ]; then
	echo "We cannot test cpu hotplug with a single cpu online"
	exit_unresolved
fi

echo 0 > tracing_on
echo > trace

: "Set $(basename $cpu) offline/online with function tracer enabled"
echo function > current_tracer
echo 1 > tracing_on
(echo 0 > $cpu/online)
(echo "forked"; sleep 1)
(echo 1 > $cpu/online)
echo 0 > tracing_on
echo nop > current_tracer

Annotation

Implementation Notes