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[ 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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.