kernel/git/next/linux-next.git/tools/perf/tests/code-reading.c, branch master

perf evlist: Add reference count checking

2026-06-30T17:17:11+00:00

Now the evlist is reference counted, add reference count checking so that gets and puts are paired and easy to debug. Reference count checking is documented here: https://perfwiki.github.io/main/reference-count-checking/ This large patch is adding accessors to evlist functions and switching to their use. There was some minor renaming as evlist__mmap is now an accessor to the mmap variable, and the original evlist__mmap is renamed to evlist__do_mmap. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alice Rogers Cc: Dapeng Mi Cc: Ingo Molnar Cc: James Clark Cc: Leo Yan Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Richter Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim

perf evlist: Add reference count

2026-06-30T17:17:10+00:00

This a no-op for most of the perf tool. The reference count is set to 1 at allocation, the put will see the 1, decrement it and perform the delete. The purpose for adding the reference count is for the python code. Prior to this change the python code would clone evlists, but this has issues if events are opened, etc. This change adds a reference count for the evlists and a later change will add it to evsels. The combination is needed for the python code to operate correctly (not hit asserts in the evsel clone), but the changes are broken apart for the sake of smaller patches. Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alice Rogers Cc: Dapeng Mi Cc: Ingo Molnar Cc: James Clark Cc: Leo Yan Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Richter Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim

perf tools: Fix uninitialized pathname on uncompressed fallback in filename__decompress()

2026-06-10T21:56:01+00:00

filename__decompress() has an early return path for files that are not actually compressed. This path returns the fd from open() directly but never writes to the pathname output parameter, leaving the caller with an uninitialized buffer despite a successful return. Callers like dso__decompress_kmodule_path() pass pathname to decompress_kmodule() which uses it to set the decompressed file path. If pathname is uninitialized, subsequent operations on the path produce undefined behavior. Fix by setting pathname to an empty string on the uncompressed path. Callers already check for an empty pathname to distinguish temporary decompressed files (which need unlink) from the original file. Reported-by: sashiko-bot Fixes: 7ac22b088afe26a4 ("perf tools: Add filename__decompress function") Cc: Jiri Olsa Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use calloc() where applicable

2026-04-09T02:21:05+00:00

Instead of using zalloc(nr_entries * sizeof_entry) that is what calloc() does. In some places where linux/zalloc.h isn't needed, remove it, add when needed and was getting it indirectly. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim

perf test: Switch cycles event to cpu-cycles

2025-10-15T14:59:12+00:00

Without a PMU perf matches an event against any PMU with the event. Unfortunately some PMU drivers advertise a "cycles" event which is typically just a core event. As tests assume a core event, switch to use "cpu-cycles" that avoids the overloaded "cycles" event on troublesome PMUs and is so far not overloaded. Note, on x86 this changes a legacy event into a sysfs one. Signed-off-by: Ian Rogers Tested-by: James Clark Signed-off-by: Namhyung Kim

perf tests: use strdup() in "Object code reading"

2025-10-13T08:58:51+00:00

Use strdup() instead of fixed PATH_MAX buffer for storing paths to not waste memory. Suggested-by: Ian Rogers Reviewed-by: Ian Rogers Signed-off-by: James Clark Signed-off-by: Namhyung Kim

perf tests: Don't retest sections in "Object code reading"

2025-10-06T19:59:11+00:00

We already only test each kcore map once, but on slow systems (particularly with network filesystems) even the non-kcore maps are slow. The test can test the same objdump output over and over which only wastes time. Generalize the skipping mechanism to track all DSOs and addresses so that each section is only tested once. On a fully loaded ARM Juno (simulating a parallel 'perf test' run) with a network filesystem, the original runtime is: real 1m51.126s user 0m19.445s sys 1m15.431s And the new runtime is: real 0m48.873s user 0m8.031s sys 0m32.353s Committer testing: # perf test "code read" 22: Object code reading : Ok # Reviewed-by: Ian Rogers Signed-off-by: James Clark Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Explicitly pass in host perf_env

2025-07-25T17:37:57+00:00

When creating a machine for the host explicitly pass in a scoped perf_env. This removes a use of the global perf_env. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250724163302.596743-17-irogers@google.com Signed-off-by: Namhyung Kim

perf test: Avoid use perf_env

2025-07-25T17:37:57+00:00

The perf_env global variable holds the host perf_env data but its use is hit and miss. Switch to using local perf_env variables and ensure scoped perf_env__init and perf_env__exit. This loses command line setting of the perf_env, but this doesn't matter for tests. So the perf_env is fully initialized, clear it with memset in perf_env__init. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250724163302.596743-13-irogers@google.com Signed-off-by: Namhyung Kim

perf test code-reading: Avoid a leak of cpus and threads

2025-07-03T02:05:26+00:00

The perf_evlist__set_maps does the necessary gets on the arguments passed, so the reference count bumping isn't necessary and creates a memory leak. Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20250624190326.2038704-3-irogers@google.com Signed-off-by: Namhyung Kim