linux-toradex.git/tools/lib/perf/cpumap.c, branch v6.6-rc3

libperf cpumap: Add "any CPU"/dummy test function

2023-05-27T12:37:13+00:00

It is common in the code currently to test a map for "empty" when in
fact the "any CPU"/dummy value of -1 is being sought. Add a new
function to enable this and document the behavior of two other
functions.

The term "any CPU" comes from perf_event_open, where the value is
consumed, but it is more typical in the code to see this value/map
referred to as the dummy value. This could be misleading due to the
dummy event and also dummy not being intention revealing, so it is hoped
to migrate the code to referring to this as "any CPU".

Reviewed-by: Kan Liang 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ali Saidi 
Cc: Athira Rajeev 
Cc: Dmitrii Dolgov <9erthalion6@gmail.com>
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jing Zhang 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kang Minchul 
Cc: Leo Yan 
Cc: Madhavan Srinivasan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Ming Wang 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Rob Herring 
Cc: Sandipan Das 
Cc: Sean Christopherson 
Cc: Suzuki Poulouse 
Cc: Thomas Richter 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230527072210.2900565-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Add equal function

2023-05-27T12:36:44+00:00

Equality is a useful property to compare after merging and
intersecting maps.

Reviewed-by: Kan Liang 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ali Saidi 
Cc: Athira Rajeev 
Cc: Dmitrii Dolgov <9erthalion6@gmail.com>
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jing Zhang 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kang Minchul 
Cc: Leo Yan 
Cc: Madhavan Srinivasan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Ming Wang 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Rob Herring 
Cc: Sandipan Das 
Cc: Sean Christopherson 
Cc: Suzuki Poulouse 
Cc: Thomas Richter 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230527072210.2900565-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Add internal nr and cpu accessors

2023-05-27T12:36:03+00:00

These accessors assume the map is non-null. Rewrite functions to use
rather than direct accesses. This also fixes a build regression for
REFCNT_CHECKING in the intersect function.

Suggested-by: Arnaldo Carvalho de Melo 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ali Saidi 
Cc: Athira Rajeev 
Cc: Dmitrii Dolgov <9erthalion6@gmail.com>
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jing Zhang 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Kang Minchul 
Cc: Leo Yan 
Cc: Madhavan Srinivasan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Ming Wang 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Rob Herring 
Cc: Sandipan Das 
Cc: Sean Christopherson 
Cc: Suzuki Poulouse 
Cc: Thomas Richter 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230527072210.2900565-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Add intersect function

2023-05-27T01:47:15+00:00

The merge function gives the union of two cpu maps. Add an intersect
function which is necessary, for example, when intersecting a PMUs
supported CPUs with user requested.

Reviewed-by: Kan Liang 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ali Saidi 
Cc: Athira Rajeev 
Cc: Dmitrii Dolgov <9erthalion6@gmail.com>
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jing Zhang 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kang Minchul 
Cc: Leo Yan 
Cc: Madhavan Srinivasan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Ming Wang 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Rob Herring 
Cc: Sandipan Das 
Cc: Sean Christopherson 
Cc: Suzuki Poulouse 
Cc: Thomas Richter 
Cc: Will Deacon 
Cc: Xing Zhengjun 
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230526215410.2435674-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Add reference count checking

2023-04-17T19:50:02+00:00

Enabled when REFCNT_CHECKING is defined. The change adds a memory
allocated pointer that is interposed between the reference counted cpu
map at a get and freed by a put. The pointer replaces the original
perf_cpu_map struct, so use of the perf_cpu_map via APIs remains
unchanged. Any use of the cpu map without the API requires two versions,
handled via the RC_CHK_ACCESS macro.

This change is intended to catch:

 - use after put: using a cpumap after you have put it will cause a
   segv.
 - unbalanced puts: two puts for a get will result in a double free
   that can be captured and reported by tools like address sanitizer,
   including with the associated stack traces of allocation and frees.
 - missing puts: if a put is missing then the get turns into a memory
   leak that can be reported by leak sanitizer, including the stack
   trace at the point the get occurs.

Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Bayduraev 
Cc: Andi Kleen 
Cc: Andrew Morton 
Cc: Andy Shevchenko 
Cc: Darren Hart 
Cc: Davidlohr Bueso 
Cc: Dmitriy Vyukov 
Cc: Eric Dumazet 
Cc: German Gomez 
Cc: Hao Luo 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Madhavan Srinivasan 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Miaoqian Lin 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Riccardo Mancini 
Cc: Shunsuke Nakamura 
Cc: Song Liu 
Cc: Stephen Brennan 
Cc: Steven Rostedt (VMware) 
Cc: Thomas Gleixner 
Cc: Thomas Richter ,
Cc: Yury Norov 
Link: https://lore.kernel.org/lkml/20230407230405.2931830-3-irogers@google.com
[ Extracted from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo

libperf: Add perf_cpu_map__refcnt() interanl accessor to use in the maps test

2023-04-17T18:52:36+00:00

To remove one more direct access to 'struct perf_cpu_map' so that we can
intercept accesses to its instantiations and refcount check it to catch
use after free, etc.

Cc: Adrian Hunter 
Cc: Alexey Bayduraev 
Cc: Dmitriy Vyukov 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Riccardo Mancini 
Cc: Stephane Eranian 
Cc: Stephen Brennan 
Link: https://lore.kernel.org/lkml/ZD1qdYjG+DL6KOfP@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

libperf: Add a perf_cpu_map__set_nr() available as an internal function for tools/perf to use

2023-04-12T17:53:35+00:00

We'll need to reference count check 'struct perf_cpu_map', so wrap
accesses to its internal state to allow intercepting accesses to its
instances.

Cc: Adrian Hunter 
Cc: Alexey Bayduraev 
Cc: Dmitriy Vyukov 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Riccardo Mancini 
Cc: Stephane Eranian 
Cc: Stephen Brennan 
Link: https://lore.kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo

libperf: Make perf_cpu_map__alloc() available as an internal function for tools/perf to use

2023-04-12T17:44:24+00:00

We had the open coded equivalent in perf_cpu_map__empty_new(), so reuse
what is in libperf.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexey Bayduraev 
Cc: Dmitriy Vyukov 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Riccardo Mancini 
Cc: Stephane Eranian 
Cc: Stephen Brennan 
Link: https://lore.kernel.org/lkml/20230407230405.2931830-3-irogers@google.com
[ Split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Const map for max()

2022-08-19T15:26:58+00:00

Allows max() to be used with 'const struct perf_cpu_maps *'.

Signed-off-by: Ian Rogers 
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Bayduraev 
Cc: Athira Jajeev 
Cc: Colin Ian King 
Cc: Dave Marchevsky 
Cc: German Gomez 
Cc: Gustavo A. R. Silva 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Kees Kook 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Riccardo Mancini 
Cc: Song Liu 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/r/20220614143353.1559597-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: More cpu map reuse by merge.

2022-04-01T19:19:35+00:00

perf_cpu_map__merge() will reuse one of its arguments if they are equal or
the other argument is NULL.

The arguments could be reused if it is known one set of values is a
subset of the other.

For example, a map of 0-1 and a map of just 0 when merged yields the map
of 0-1.

Currently a new map is created rather than adding a reference count to
the original 0-1 map.

Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Antonov 
Cc: Alexander Shishkin 
Cc: Alexei Starovoitov 
Cc: Alexey Bayduraev 
Cc: Andi Kleen 
Cc: Andrii Nakryiko 
Cc: Daniel Borkmann 
Cc: German Gomez 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Fastabend 
Cc: John Garry 
Cc: KP Singh 
Cc: Kajol Jain 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Martin KaFai Lau 
Cc: Mathieu Poirier 
Cc: Mike Leach 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Riccardo Mancini 
Cc: Song Liu 
Cc: Stephane Eranian 
Cc: Suzuki Poulouse 
Cc: Will Deacon 
Cc: Yonghong Song 
Cc: bpf@vger.kernel.org
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20220328232648.2127340-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo