Merge tag 'perf-tools-for-v6.17-2025-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Namhyung Kim:
 "Build-ID processing goodies:

     Build-IDs are content based hashes to link regions of memory to ELF
     files in post processing. They have been available in distros for
     quite a while:

       $ file /bin/bash
       /bin/bash: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV),
       dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2,
       BuildID[sha1]=707a1c670cd72f8e55ffedfbe94ea98901b7ce3a,
       for GNU/Linux 3.2.0, stripped

     It is possible to ask the kernel to get it from mmap executable
     backing storage at time they are being put in place and send it as
     metadata at that moment to have in perf.data.

     Prefer that across the board to speed up 'record' time - it post
     processes the samples to find binaries touched by any samples and
     to save them with build-ID. It can skip reading build-ID in
     userspace if it comes from the kernel.

  perf record:

   * Make --buildid-mmap default.  The kernel can generate MMAP2 events
     with a build-ID from ELF header.  Use that by default instead of using
     inode and device ID to identify binaries.  It also can be disabled
     with --no-buildid-mmap.

   * Use BPF for -u/--uid option to sample processes belong to a user.
     BPF can track user processes more accurately and the existing logic
     often fails to get the list of processes due to race with reading the
     /proc filesystem.

   * Generate PERF_RECORD_BPF_METADATA when it profiles BPF programs and
     they have variables starting with "bpf_metadata_".  This will help to
     identify BPF objects used in the profile.  This has been supported in
     bpftool for some time and allows the recording of metadata such as
     commit hashes, versions, etc, that now gets recorded in perf.data as
     well.

   * Collect list of DSOs touched in the sample callchains as well as in
     the sample itself.  This would increase the processing time at the end
     of record, but can improve the data quality.

  perf stat:

   * Add a new 'drm' pseudo-PMU support like in 'hwmon'.  It can collect
     DRM usage stats using fdinfo in /proc.

     On my Intel laptop, it shows like below:

       $ perf list drm
       ...

       drm:
         drm-active-stolen-system0
              [Total memory active in one or more engines. Unit: drm_i915]
         drm-active-system0
              [Total memory active in one or more engines. Unit: drm_i915]
         drm-engine-capacity-video
              [Engine capacity. Unit: drm_i915]
         drm-engine-copy
              [Utilization in ns. Unit: drm_i915]
         drm-engine-render
              [Utilization in ns. Unit: drm_i915]
         drm-engine-video
              [Utilization in ns. Unit: drm_i915]
         ...

       $ sudo perf stat -a -e drm-engine-render,drm-engine-video,drm-engine-capacity-video sleep 1

        Performance counter stats for 'system wide':

       48,137,316,988,873 ns       drm-engine-render
           34,452,696,746 ns       drm-engine-video
                       20 capacity drm-engine-capacity-video

              1.002086194 seconds time elapsed

  perf list

   * Add description for software events.  The description is in JSON format
     and the event parser now can handle the software events like others
     (for example, it's case-insensitive and subject to wildcard matching).

       $ perf list software

       List of pre-defined events (to be used in -e or -M):

       software:
         alignment-faults
              [Number of kernel handled memory alignment faults. Unit: software]
         bpf-output
              [An event used by BPF programs to write to the perf ring buffer. Unit: software]
         cgroup-switches
              [Number of context switches to a task in a different cgroup. Unit: software]
         context-switches
              [Number of context switches [This event is an alias of cs]. Unit: software]
         cpu-clock
              [Per-CPU high-resolution timer based event. Unit: software]
         cpu-migrations
              [Number of times a process has migrated to a new CPU [This event is an alias of migrations]. Unit: software]
         cs
              [Number of context switches [This event is an alias of context-switches]. Unit: software]
         dummy
              [A placeholder event that doesn't count anything. Unit: software]
         emulation-faults
              [Number of kernel handled unimplemented instruction faults handled through emulation. Unit: software]
         faults
              [Number of page faults [This event is an alias of page-faults]. Unit: software]
         major-faults
              [Number of major page faults. Major faults require I/O to handle. Unit: software]
         migrations
              [Number of times a process has migrated to a new CPU [This event is an alias of cpu-migrations]. Unit: software]
         minor-faults
              [Number of minor page faults. Minor faults don't require I/O to handle. Unit: software]
         page-faults
              [Number of page faults [This event is an alias of faults]. Unit: software]
         task-clock
              [Per-task high-resolution timer based event. Unit: software]

  perf ftrace:

   * Add -e/--events option to perf ftrace latency to measure latency
     between the two events instead of a function.

       $ sudo perf ftrace latency -ab -e i915_request_wait_begin,i915_request_wait_end --hide-empty -- sleep 1
       #   DURATION     |      COUNT | GRAPH                                |
          256 -  512 us |          4 | ######                               |
            2 -    4 ms |          2 | ###                                  |
            4 -    8 ms |         12 | ###################                  |
            8 -   16 ms |         10 | ################                     |

       # statistics  (in usec)
         total time:               194915
           avg time:                 6961
           max time:                12855
           min time:                  373
              count:                   28

   * Add new function graph tracer options (--graph-opts) to display more
     info like arguments and return value.  They will be passed to the
     kernel ftrace directly.

       $ sudo perf ftrace -G vfs_write --graph-opts retval,retaddr
       # tracer: function_graph
       #
       # CPU  DURATION                  FUNCTION CALLS
       # |     |   |                     |   |   |   |
       ...
       5)               |  mutex_unlock() { /* <-rb_simple_write+0xda/0x150 */
       5)   0.188 us    |    local_clock(); /* <-lock_release+0x2ad/0x440 ret=0x3bf2a3cf90e */
       5)               |    rt_mutex_slowunlock() { /* <-rb_simple_write+0xda/0x150 */
       5)               |      _raw_spin_lock_irqsave() { /* <-rt_mutex_slowunlock+0x4f/0x200 */
       5)   0.123 us    |        preempt_count_add(); /* <-_raw_spin_lock_irqsave+0x23/0x90 ret=0x0 */
       5)   0.128 us    |        local_clock(); /* <-__lock_acquire.isra.0+0x17a/0x740 ret=0x3bf2a3cfc8b */
       5)   0.086 us    |        do_raw_spin_trylock(); /* <-_raw_spin_lock_irqsave+0x4a/0x90 ret=0x1 */
       5)   0.845 us    |      } /* _raw_spin_lock_irqsave ret=0x292 */
       ...

  Misc:

   * Add perf archive --exclude-buildids <FILE> option to skip some binaries.
     The format of the FILE should be same as an output of perf buildid-list.

   * Get rid of dependency of libcrypto.  It was just to get SHA-1 hash so
     implement it directly like in the kernel.  A side effect is that it
     needs -fno-strict-aliasing compiler option (again, like in the kernel).

   * Convert all shell script tests to use bash"

* tag 'perf-tools-for-v6.17-2025-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (179 commits)
  perf record: Cache build-ID of hit DSOs only
  perf test: Ensure lock contention using pipe mode
  perf python: Stop using deprecated PyUnicode_AsString()
  perf list: Skip ABI PMUs when printing pmu values
  perf list: Remove tracepoint printing code
  perf tp_pmu: Add event APIs
  perf tp_pmu: Factor existing tracepoint logic to new file
  perf parse-events: Remove non-json software events
  perf jevents: Add common software event json
  perf tools: Remove libtraceevent in .gitignore
  perf test: Fix comment ordering
  perf sort: Use perf_env to set arch sort keys and header
  perf test: Move PERF_SAMPLE_WEIGHT_STRUCT parsing to common test
  perf sample: Remove arch notion of sample parsing
  perf env: Remove global perf_env
  perf trace: Avoid global perf_env with evsel__env
  perf auxtrace: Pass perf_env from session through to mmap read
  perf machine: Explicitly pass in host perf_env
  perf bench synthesize: Avoid use of global perf_env
  perf top: Make perf_env locally scoped
  ...

1 files changed, 53 insertions, 29 deletions

diff --git a/tools/perf/scripts/python/flamegraph.py b/tools/perf/scripts/python/flamegraph.py
index cf7ce8229a6c..ad735990c5be 100755
--- a/tools/perf/scripts/python/flamegraph.py
+++ b/tools/perf/scripts/python/flamegraph.py
@@ -18,7 +18,6 @@
 # pylint: disable=missing-class-docstring
 # pylint: disable=missing-function-docstring
 
-from __future__ import print_function
 import argparse
 import hashlib
 import io
@@ -26,9 +25,10 @@ import json
 import os
 import subprocess
 import sys
+from typing import Dict, Optional, Union
 import urllib.request
 
-minimal_html = """<head>
+MINIMAL_HTML = """<head>
   <link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/d3-flamegraph.css">
 </head>
 <body>
@@ -50,20 +50,20 @@ minimal_html = """<head>
 
 # pylint: disable=too-few-public-methods
 class Node:
-    def __init__(self, name, libtype):
+    def __init__(self, name: str, libtype: str):
         self.name = name
         # "root" | "kernel" | ""
         # "" indicates user space
         self.libtype = libtype
-        self.value = 0
-        self.children = []
+        self.value: int = 0
+        self.children: list[Node] = []
 
-    def to_json(self):
+    def to_json(self) -> Dict[str, Union[str, int, list[Dict]]]:
         return {
             "n": self.name,
             "l": self.libtype,
             "v": self.value,
-            "c": self.children
+            "c": [x.to_json() for x in self.children]
         }
 
 
@@ -73,7 +73,7 @@ class FlameGraphCLI:
         self.stack = Node("all", "root")
 
     @staticmethod
-    def get_libtype_from_dso(dso):
+    def get_libtype_from_dso(dso: Optional[str]) -> str:
         """
         when kernel-debuginfo is installed,
         dso points to /usr/lib/debug/lib/modules/*/vmlinux
@@ -84,7 +84,7 @@ class FlameGraphCLI:
         return ""
 
     @staticmethod
-    def find_or_create_node(node, name, libtype):
+    def find_or_create_node(node: Node, name: str, libtype: str) -> Node:
         for child in node.children:
             if child.name == name:
                 return child
@@ -93,7 +93,12 @@ class FlameGraphCLI:
         node.children.append(child)
         return child
 
-    def process_event(self, event):
+    def process_event(self, event) -> None:
+        # ignore events where the event name does not match
+        # the one specified by the user
+        if self.args.event_name and event.get("ev_name") != self.args.event_name:
+            return
+
         pid = event.get("sample", {}).get("pid", 0)
         # event["dso"] sometimes contains /usr/lib/debug/lib/modules/*/vmlinux
         # for user-space processes; let's use pid for kernel or user-space distinction
@@ -101,7 +106,7 @@ class FlameGraphCLI:
             comm = event["comm"]
             libtype = "kernel"
         else:
-            comm = "{} ({})".format(event["comm"], pid)
+            comm = f"{event['comm']} ({pid})"
             libtype = ""
         node = self.find_or_create_node(self.stack, comm, libtype)
 
@@ -116,20 +121,30 @@ class FlameGraphCLI:
             node = self.find_or_create_node(node, name, libtype)
         node.value += 1
 
-    def get_report_header(self):
+    def get_report_header(self) -> str:
         if self.args.input == "-":
             # when this script is invoked with "perf script flamegraph",
             # no perf.data is created and we cannot read the header of it
             return ""
 
         try:
-            output = subprocess.check_output(["perf", "report", "--header-only"])
-            return output.decode("utf-8")
+            # if the file name other than perf.data is given,
+            # we read the header of that file
+            if self.args.input:
+                output = subprocess.check_output(["perf", "report", "--header-only",
+                                                  "-i", self.args.input])
+            else:
+                output = subprocess.check_output(["perf", "report", "--header-only"])
+
+            result = output.decode("utf-8")
+            if self.args.event_name:
+                result += "\nFocused event: " + self.args.event_name
+            return result
         except Exception as err:  # pylint: disable=broad-except
-            print("Error reading report header: {}".format(err), file=sys.stderr)
+            print(f"Error reading report header: {err}", file=sys.stderr)
             return ""
 
-    def trace_end(self):
+    def trace_end(self) -> None:
         stacks_json = json.dumps(self.stack, default=lambda x: x.to_json())
 
         if self.args.format == "html":
@@ -153,7 +168,8 @@ graph template (--template PATH) or use another output format (--format
 FORMAT).""",
                               file=sys.stderr)
                         if self.args.input == "-":
-                            print("""Not attempting to download Flame Graph template as script command line
+                            print(
+"""Not attempting to download Flame Graph template as script command line
 input is disabled due to using live mode. If you want to download the
 template retry without live mode. For example, use 'perf record -a -g
 -F 99 sleep 60' and 'perf script report flamegraph'. Alternatively,
@@ -162,37 +178,40 @@ https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/templates/d3-flamegraph-b
 and place it at:
 /usr/share/d3-flame-graph/d3-flamegraph-base.html""",
                                   file=sys.stderr)
-                            quit()
+                            sys.exit(1)
                         s = None
-                        while s != "y" and s != "n":
-                            s = input("Do you wish to download a template from cdn.jsdelivr.net? (this warning can be suppressed with --allow-download) [yn] ").lower()
+                        while s not in ["y", "n"]:
+                            s = input("Do you wish to download a template from cdn.jsdelivr.net?" +
+                                      "(this warning can be suppressed with --allow-download) [yn] "
+                                      ).lower()
                         if s == "n":
-                            quit()
-                    template = "https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/templates/d3-flamegraph-base.html"
+                            sys.exit(1)
+                    template = ("https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/templates/"
+                                "d3-flamegraph-base.html")
                     template_md5sum = "143e0d06ba69b8370b9848dcd6ae3f36"
 
             try:
-                with urllib.request.urlopen(template) as template:
+                with urllib.request.urlopen(template) as url_template:
                     output_str = "".join([
-                        l.decode("utf-8") for l in template.readlines()
+                        l.decode("utf-8") for l in url_template.readlines()
                     ])
             except Exception as err:
                 print(f"Error reading template {template}: {err}\n"
                       "a minimal flame graph will be generated", file=sys.stderr)
-                output_str = minimal_html
+                output_str = MINIMAL_HTML
                 template_md5sum = None
 
             if template_md5sum:
                 download_md5sum = hashlib.md5(output_str.encode("utf-8")).hexdigest()
                 if download_md5sum != template_md5sum:
                     s = None
-                    while s != "y" and s != "n":
+                    while s not in ["y", "n"]:
                         s = input(f"""Unexpected template md5sum.
 {download_md5sum} != {template_md5sum}, for:
 {output_str}
 continue?[yn] """).lower()
                     if s == "n":
-                        quit()
+                        sys.exit(1)
 
             output_str = output_str.replace("/** @options_json **/", options_json)
             output_str = output_str.replace("/** @flamegraph_json **/", stacks_json)
@@ -206,12 +225,12 @@ continue?[yn] """).lower()
             with io.open(sys.stdout.fileno(), "w", encoding="utf-8", closefd=False) as out:
                 out.write(output_str)
         else:
-            print("dumping data to {}".format(output_fn))
+            print(f"dumping data to {output_fn}")
             try:
                 with io.open(output_fn, "w", encoding="utf-8") as out:
                     out.write(output_str)
             except IOError as err:
-                print("Error writing output file: {}".format(err), file=sys.stderr)
+                print(f"Error writing output file: {err}", file=sys.stderr)
                 sys.exit(1)
 
 
@@ -235,6 +254,11 @@ if __name__ == "__main__":
                         default=False,
                         action="store_true",
                         help="allow unprompted downloading of HTML template")
+    parser.add_argument("-e", "--event",
+                        default="",
+                        dest="event_name",
+                        type=str,
+                        help="specify the event to generate flamegraph for")
 
     cli_args = parser.parse_args()
     cli = FlameGraphCLI(cli_args)