Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 6.6 21/22] selftests/ftrace: Fix event filter target_func selection | Date | Sun, 7 Apr 2024 09:12:20 -0400 |
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From: Mark Rutland <mark.rutland@arm.com>
[ Upstream commit 8ecab2e64572f1aecdfc5a8feae748abda6e3347 ]
The event filter function test has been failing in our internal test farm:
| # not ok 33 event filter function - test event filtering on functions
Running the test in verbose mode indicates that this is because the test erroneously determines that kmem_cache_free() is the most common caller of kmem_cache_free():
# # + cut -d: -f3 trace # # + sed s/call_site=([^+]*)+0x.*/1/ # # + sort # # + uniq -c # # + sort # # + tail -n 1 # # + sed s/^[ 0-9]*// # # + target_func=kmem_cache_free
.. and as kmem_cache_free() doesn't call itself, setting this as the filter function for kmem_cache_free() results in no hits, and consequently the test fails:
# # + grep kmem_cache_free trace # # + grep kmem_cache_free # # + wc -l # # + hitcnt=0 # # + grep kmem_cache_free trace # # + grep -v kmem_cache_free # # + wc -l # # + misscnt=0 # # + [ 0 -eq 0 ] # # + exit_fail
This seems to be because the system in question has tasks with ':' in their name (which a number of kernel worker threads have). These show up in the trace, e.g.
test:.sh-1299 [004] ..... 2886.040608: kmem_cache_free: call_site=putname+0xa4/0xc8 ptr=000000000f4d22f4 name=names_cache
.. and so when we try to extact the call_site with:
cut -d: -f3 trace | sed 's/call_site=\([^+]*\)+0x.*/\1/'
.. the 'cut' command will extrace the column containing 'kmem_cache_free' rather than the column containing 'call_site=...', and the 'sed' command will leave this unchanged. Consequently, the test will decide to use 'kmem_cache_free' as the filter function, resulting in the failure seen above.
Fix this by matching the 'call_site=<func>' part specifically to extract the function name.
Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Cc: linux-kselftest@vger.kernel.org Cc: linux-trace-kernel@vger.kernel.org Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- .../selftests/ftrace/test.d/filter/event-filter-function.tc | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc b/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc index 2de7c61d1ae30..3f74c09c56b62 100644 --- a/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc +++ b/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc @@ -24,7 +24,7 @@ echo 0 > events/enable echo "Get the most frequently calling function" sample_events -target_func=`cut -d: -f3 trace | sed 's/call_site=\([^+]*\)+0x.*/\1/' | sort | uniq -c | sort | tail -n 1 | sed 's/^[ 0-9]*//'` +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 -- 2.43.0
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