linux-stable.git/tools/perf/util/hist.c, branch linux-rolling-stable

perf c2c: Fix hist entry and format list leaks in c2c_he_free()

2026-07-24T14:20:17+00:00

[ Upstream commit fe68cf349fb343c0a7cb6c4fe6c3de4f4afe8d1c ]

c2c_he_free() calls hists__delete_entries() which only walks the
output-sorted entries tree.  During c2c resort, when cacheline entries
are merged and the redundant entry is freed, the inner hists have not
been output-resorted yet, so hists->entries is empty.  The actual inner
hist_entry objects live in entries_in_array[] and entries_collapsed,
which are never walked, leaking all inner hist_entry objects for every
merged cacheline.

Additionally, the dynamically allocated format entries on hists->list
are never unregistered or freed.

Fix both issues by switching to hists__delete_all_entries() which walks
all rb_root trees, and calling perf_hpp__reset_output_field() to clean
up format entries.

Fixes: bf0e0d407ea09ce5 ("perf c2c report: Add sample processing")
Reported-by: sashiko-bot 
Cc: Jiri Olsa 
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf hists: Fix snprintf() in hists__scnprintf_title() UID filter path

2026-07-24T14:20:09+00:00

[ Upstream commit 227a8748742f0263f1fe3131449b44563b77a209 ]

hists__scnprintf_title() accumulates formatted output into a buffer
using scnprintf() for all filter clauses except the UID filter, which
uses snprintf().  If the buffer fills up and snprintf() returns more
than the remaining space, printed exceeds size and the next 'size -
printed' underflows, causing later scnprintf() calls to write past
the buffer.

Switch the UID filter clause to scnprintf() to match the rest of the
function.

Fixes: 25c312dbf88ca402 ("perf hists: Move hists__scnprintf_title() away from the TUI code")
Reported-by: sashiko-bot 
Reviewed-by: Ian Rogers 
Cc: Arnaldo Carvalho de Melo 
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

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 report: Add comm_nodigit sort key

2026-03-26T22:22:18+00:00

The "comm" column allows grouping events by the process command. It is
intended to group like programs, despite having different PIDs. But some
workloads may adjust their own command, so that a unique identifier
(e.g. a PID or some other numeric value) is part of the command name.
This destroys the utility of "comm", forcing perf to place each unique
process name into its own bucket, which can contribute to a
combinatorial explosion of memory use in perf report.

Create a less strict version of this column, which ignores digits when
comparing command names. Commands whose names are the same (ignoring
digits) are sorted into the same histogram buckets, and displayed with
the placeholder value "" in the place of digits. For example,
hypothetical command names "kworker/1" "kworker/2" "kworker/3" would
sort into the same bucket and be represented as "kworker/".

Committer testing:

  $ perf report -s comm,comm_nodigit | grep -F ""
       0.01%  CPU 6/TCG        CPU /TCG
       0.01%  kworker/53:2-mm  kworker/:-mm
       0.01%  migration/24     migration/
       0.01%  kworker/24:1-ev  kworker/:-ev
       0.01%  llvmpipe-8       llvmpipe-

Signed-off-by: Stephen Brennan 
Signed-off-by: Namhyung Kim

perf map_symbol: Switch from holding maps to holding thread

2026-01-23T19:58:39+00:00

maps may belong to >1 thread. In contexts like symbolization
information from the thread may be useful, such as the ELF machine.

As the maps can be gained from the thread switch from holding maps in
struct map_symbol to holding the thread.

Holding the maps in addr_location is also redundant, switch this to
using thread__maps.

Reviewed-by: James Clark 
Signed-off-by: Ian Rogers 
Cc: Aditya Bodkhe 
Cc: Adrian Hunter 
Cc: Albert Ou 
Cc: Alexander Shishkin 
Cc: Alexandre Ghiti 
Cc: Athira Rajeev 
Cc: Bill Wendling 
Cc: Dr. David Alan Gilbert 
Cc: Guo Ren 
Cc: Howard Chu 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Julia Lawall 
Cc: Justin Stitt 
Cc: Krzysztof Łopatowski 
Cc: Leo Yan 
Cc: Namhyung Kim 
Cc: Nathan Chancellor 
Cc: Nick Desaulniers 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Peter Zijlstra 
Cc: Sergei Trofimovich 
Cc: Shimin Guo 
Cc: Suchit Karunakaran 
Cc: Thomas Falcon 
Cc: Tianyou Li 
Cc: Will Deacon 
Cc: Zecheng Li 
Signed-off-by: Arnaldo Carvalho de Melo

perf hist: In init, ensure mem_info is put on error paths

2025-12-03T19:07:40+00:00

Rather than exit the internal map_symbols directly, put the mem-info
that does this and also lowers the reference count on the mem-info
itself otherwise the mem-info is being leaked.

Fixes: 56e144fe98260a0f ("perf mem_info: Add and use map_symbol__exit and addr_map_symbol__exit")
Signed-off-by: Ian Rogers 
Reviewed-by: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim

perf sample: Remove arch notion of sample parsing

2025-07-25T17:37:58+00:00

By definition arch sample parsing and synthesis will inhibit certain
kinds of cross-platform record then analysis (report, script,
etc.). Remove arch_perf_parse_sample_weight and
arch_perf_synthesize_sample_weight replacing with a common
implementation. Combine perf_sample p_stage_cyc and retire_lat as
weight3 to capture the differing uses regardless of compiled for
architecture.

Signed-off-by: Ian Rogers 
Link: https://lore.kernel.org/r/20250724163302.596743-21-irogers@google.com
Signed-off-by: Namhyung Kim

perf hist: Hide unused mem stat columns

2025-05-02T18:36:14+00:00

Some mem_stat types don't use all 8 columns.  And there are cases only
samples in certain kinds of mem_stat types are available only.  For that
case hide columns which has no samples.

The new output for the previous data would be:

  $ perf mem report -F overhead,op,comm --stdio
  ...
  #           ------ Mem Op -------
  # Overhead     Load  Store  Other  Command
  # ........  .....................  ...............
  #
      44.85%    21.1%  30.7%  48.3%  swapper
      26.82%    98.8%   0.3%   0.9%  netsli-prober
       7.19%    51.7%  13.7%  34.6%  perf
       5.81%    89.7%   2.2%   8.1%  qemu-system-ppc
       4.77%   100.0%   0.0%   0.0%  notifications_c
       1.77%    95.9%   1.2%   3.0%  MemoryReleaser
       0.77%    71.6%   4.1%  24.3%  DefaultEventMan
       0.19%    66.7%  22.2%  11.1%  gnome-shell
       ...

On Intel machines, the event is only for loads or stores so it'll have
only one column:

  #            Mem Op
  # Overhead     Load  Command
  # ........  .......  ...............
  #
      20.55%   100.0%  swapper
      17.13%   100.0%  chrome
       9.02%   100.0%  data-loop.0
       6.26%   100.0%  pipewire-pulse
       5.63%   100.0%  threaded-ml
       5.47%   100.0%  GraphRunner
       5.37%   100.0%  AudioIP~allback
       5.30%   100.0%  Chrome_ChildIOT
       3.17%   100.0%  Isolated Web Co
       ...

Committer testing:

  # grep "model name" -m1 /proc/cpuinfo
  model name	: AMD Ryzen 9 9950X3D 16-Core Processo
  # perf mem report -F overhead,op,comm --stdio
  # Total Lost Samples: 0
  #
  # Samples: 2K of event 'cycles:P'
  # Total weight : 2637
  # Sort order   : local_weight,mem,sym,dso,symbol_daddr,dso_daddr,snoop,tlb,locked,blocked,local_ins_lat,local_p_stage_cyc
  #
  #           ------ Mem Op -------
  # Overhead     Load  Store  Other  Command
  # ........  .....................  ...............
  #
      61.02%    14.4%  25.5%  60.1%  swapper
       5.61%    26.4%  13.5%  60.1%  Isolated Web Co
       5.50%    21.4%  29.7%  49.0%  perf
       4.74%    27.2%  15.2%  57.6%  gnome-shell
       4.63%    33.6%  11.5%  54.9%  mdns_service
       4.29%    28.3%  12.4%  59.3%  ptyxis
       2.16%    24.6%  19.3%  56.1%  DOM Worker
       0.99%    23.1%  34.6%  42.3%  firefox
       0.72%    26.3%  15.8%  57.9%  IPC I/O Parent
       0.61%    12.5%  12.5%  75.0%  kworker/u130:20
       0.61%    37.5%  18.8%  43.8%  podman
       0.57%    33.3%   6.7%  60.0%  Timer
       0.53%    14.3%   7.1%  78.6%  KMS thread
       0.49%    30.8%   7.7%  61.5%  kworker/u130:3-
       0.46%    41.7%  33.3%  25.0%  IPDL Background

Signed-off-by: Namhyung Kim 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Link: https://lore.kernel.org/r/20250430205548.789750-9-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf hist: Basic support for mem_stat accounting

2025-05-02T18:36:14+00:00

Add a logic to account he->mem_stat based on mem_stat_type in hists.

Each mem_stat entry will have different meaning based on the type so the
index in the array is calculated at runtime using the corresponding
value in the sample.data_src.

Still hists has no mem_stat_types yet so this code won't work for now.

Later hists->mem_stat_types will be allocated based on what users want
in the output actually.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Link: https://lore.kernel.org/r/20250430205548.789750-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf hist: Add struct he_mem_stat

2025-05-02T18:36:14+00:00

The 'struct he_mem_stat' is to save detailed information about memory
instruction.  It'll be used to show breakdown of various data from
PERF_SAMPLE_DATA_SRC.  Note that this structure is generic and the
contents will be different depending on actual data it'll use later.

The information about the actual data will be saved in 'struct hists'
and its length is in nr_mem_stats.  This commit just adds ground works
and does nothing since hists->nr_mem_stats is 0 for now.

Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Leo Yan 
Cc: Peter Zijlstra 
Cc: Ravi Bangoria 
Link: https://lore.kernel.org/r/20250430205548.789750-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo