tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc

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

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc
Extension
.tc
Size
2479 bytes
Lines
110
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

#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: event filter function - test event filtering on functions
# requires: set_event events/kmem/kmem_cache_free/filter
# flags: instance

fail() { #msg
    echo $1
    exit_fail
}

sample_events() {
    echo 1 > events/kmem/kmem_cache_free/enable
    echo 1 > tracing_on
    ls > /dev/null
    echo 0 > tracing_on
    echo 0 > events/kmem/kmem_cache_free/enable
}

echo 0 > tracing_on
echo 0 > events/enable

# Clear functions caused by page cache; run sample_events twice
sample_events
sample_events

echo "Get the most frequently calling function"
echo > trace
sample_events

target_func=`cat trace | grep -o 'call_site=\([^+]*\)' | sed 's/call_site=//' | sort | uniq -c | sort | tail -n 1 | sed 's/^[ 0-9]*//'`
if [ -z "$target_func" ]; then
    exit_fail
fi
echo > trace

echo "Test event filter function name"
echo "call_site.function == $target_func" > events/kmem/kmem_cache_free/filter

sample_events
max_retry=10
while [ `grep kmem_cache_free trace| wc -l` -eq 0 ]; do
sample_events
max_retry=$((max_retry - 1))
if [ $max_retry -eq 0 ]; then
	exit_fail
fi
done

hitcnt=`grep kmem_cache_free trace| grep $target_func | wc -l`
misscnt=`grep kmem_cache_free trace| grep -v $target_func | wc -l`

if [ $hitcnt -eq 0 ]; then
	exit_fail
fi

if [ $misscnt -gt 0 ]; then
	exit_fail
fi

address=`grep " ${target_func}\$" /proc/kallsyms | cut -d' ' -f1`

echo "Test event filter function address"
echo "call_site.function == 0x$address" > events/kmem/kmem_cache_free/filter
echo > trace
sample_events
max_retry=10
while [ `grep kmem_cache_free trace| wc -l` -eq 0 ]; do
sample_events
max_retry=$((max_retry - 1))

Annotation

Implementation Notes