linux-toradex.git/tools/lib/perf/cpumap.c, branch v6.16

libperf cpumap: Add ability to create CPU from a single CPU number

2025-05-12T17:18:16+00:00

Add perf_cpu_map__new_int() so that a CPU map can be created from a
single integer.

Signed-off-by: Ian Rogers 
Tested-by: Kan Liang 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Dominique Martinet 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Weilin Wang 
Cc: Yicong Yang 
Link: https://lore.kernel.org/r/20250403194337.40202-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf cpumap: Reduce cpu size from int to int16_t

2025-02-27T16:47:25+00:00

Fewer than 32k logical CPUs are currently supported by perf. A cpumap
is indexed by an integer (see perf_cpu_map__cpu) yielding a perf_cpu
that wraps a 4-byte int for the logical CPU - the wrapping is done
deliberately to avoid confusing a logical CPU with an index into a
cpumap. Using a 4-byte int within the perf_cpu is larger than required
so this patch reduces it to the 2-byte int16_t. For a cpumap
containing 16 entries this will reduce the array size from 64 to 32
bytes. For very large servers with lots of logical CPUs the size
savings will be greater.

Signed-off-by: Ian Rogers 
Reviewed-by: James Clark 
Link: https://lore.kernel.org/r/20250210191231.156294-1-irogers@google.com
Signed-off-by: Namhyung Kim

libperf cpumap: Grow array of read CPUs in smaller increments

2024-12-09T20:52:41+00:00

Instead of growing the array by 2048, grow by the larger of the current
range or 16.

As ranges are typical for things like the online CPUs this will mean a
single allocation happens.

While uncore CPU maps will grow 16 at a time which is a value that is
generous except say on large servers.

Reviewed-by: Leo Yan 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ben Gainey 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Kyle Meyer 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20241206044035.1062032-9-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf cpumap: Remove perf_cpu_map__read()

2024-12-09T20:52:41+00:00

Function is no longer used and duplicates the parsing logic from
perf_cpu_map__new().

Remove to allow simplification.

Reviewed-by: Leo Yan 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ben Gainey 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Kyle Meyer 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20241206044035.1062032-8-irogers@google.com
[ Applied manually to cope with "libperf cpumap: Refactor perf_cpu_map__merge()" ]
Signed-off-by: Arnaldo Carvalho de Melo

libperf cpumap: Remove use of perf_cpu_map__read()

2024-12-09T20:52:41+00:00

Remove use of a FILE and switch to reading a string that is then
passed to perf_cpu_map__new().

Being able to remove perf_cpu_map__read() avoids duplicated parsing
logic.

Reviewed-by: Leo Yan 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ben Gainey 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Kyle Meyer 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20241206044035.1062032-7-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf cpumap: Be tolerant of newline at the end of a cpumask

2024-12-09T20:52:41+00:00

File cpumasks often have a newline that shouldn't trigger the invalid
parsing case in perf_cpu_map__new().

Reviewed-by: Leo Yan 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ben Gainey 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Kyle Meyer 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20241206044035.1062032-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf cpumap: Hide/reduce scope of MAX_NR_CPUS

2024-12-09T20:52:41+00:00

Avoid redefinition of MAX_NR_CPUS as a global constant, the original
definition is tools/perf/perf.h.

Reviewed-by: Leo Yan 
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ben Gainey 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Kyle Meyer 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20241206044035.1062032-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf cpumap: Refactor perf_cpu_map__merge()

2024-12-09T20:52:41+00:00

The perf_cpu_map__merge() function has two arguments, 'orig' and
'other'.  The function definition might cause confusion as it could give
the impression that the CPU maps in the two arguments are copied into a
new allocated structure, which is then returned as the result.

The purpose of the function is to merge the CPU map 'other' into the CPU
map 'orig'.  This commit changes the 'orig' argument to a pointer to
pointer, so the new result will be updated into 'orig'.

The return value is changed to an int type, as an error number or 0 for
success.

Update callers and tests for the new function definition.

Reviewed-by: Adrian Hunter 
Signed-off-by: Leo Yan 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/r/20241107125308.41226-2-leo.yan@arm.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf cpumap: Ensure empty cpumap is NULL from alloc

2024-03-21T13:41:28+00:00

Potential corner cases could cause a cpumap to be allocated with size
0, but an empty cpumap should be represented as NULL. Add a path in
perf_cpu_map__alloc() to ensure this.

Suggested-by: James Clark 
Signed-off-by: Ian Rogers 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexandre Ghiti 
Cc: Andrew Jones 
Cc: André Almeida 
Cc: Athira Rajeev 
Cc: Atish Patra 
Cc: Changbin Du 
Cc: Darren Hart 
Cc: Davidlohr Bueso 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: K Prateek Nayak 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Nick Desaulniers 
Cc: Paolo Bonzini 
Cc: Paran Lee 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Sandipan Das 
Cc: Sean Christopherson 
Cc: Steinar H. Gunderson 
Cc: Suzuki Poulouse 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: Yang Jihong 
Cc: Yang Li 
Cc: Yanteng Si 
Closes: https://lore.kernel.org/lkml/2cd09e7c-eb88-6726-6169-647dcd0a8101@arm.com/
Link: https://lore.kernel.org/r/20240202234057.2085863-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf cpumap: Add any, empty and min helpers

2024-03-21T13:41:28+00:00

Additional helpers to better replace perf_cpu_map__has_any_cpu_or_is_empty().

Signed-off-by: Ian Rogers 
Acked-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexandre Ghiti 
Cc: Andrew Jones 
Cc: André Almeida 
Cc: Athira Rajeev 
Cc: Atish Patra 
Cc: Changbin Du 
Cc: Darren Hart 
Cc: Davidlohr Bueso 
Cc: Huacai Chen 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: K Prateek Nayak 
Cc: Kajol Jain 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Mike Leach 
Cc: Nick Desaulniers 
Cc: Paolo Bonzini 
Cc: Paran Lee 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Cc: Sandipan Das 
Cc: Sean Christopherson 
Cc: Steinar H. Gunderson 
Cc: Suzuki Poulouse 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: Yang Jihong 
Cc: Yang Li 
Cc: Yanteng Si 
Link: https://lore.kernel.org/r/20240202234057.2085863-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo