Home
Reading
Searching
Subscribe
Sponsors
Statistics
Posting
Contact
Spam
Lists
Links
About
Hosting
Filtering
Features Download
Marketing
Archives
FAQ
Blog
 
Gmane
From: Namhyung Kim <namhyung <at> kernel.org>
Subject: [RFC 00/14] perf tools: Introduce new 'ftrace' command
Newsgroups: gmane.linux.kernel
Date: Tuesday 23rd April 2013 08:30:58 UTC (over 3 years ago)
Hello,

This patchset implements a front-end tool for kernel's ftrace.  It
uses function_graph tracer by default and normal function tracer is
also supported.  (Of course you need to enable those tracers in your
kernel first.)

NOTE: It's in very early stage, so may contain many rough edges.

It consists of 4 subcommands: live, record, show and report.

'perf ftrace live' just triggers ftrace and relay kernel buffer
contents to stdout.  It does no processing in the tool side.

'perf ftrace record' starts ftrace and saves its result to per-cpu
files and a perf.header file in the perf.data.dir directory.
Recording was done by multiple threads (a thread per cpu) in order not
to miss events overrun.  The perf.header file is compatible to current
perf.data file and contains useful information and sample data.

The sample data were synthesized for each recorded cpu to provide more
information - I'm not sure it's really needed though. :)

Once you had run 'perf ftrace record', you could play with other
subcommands.

'perf ftrace show' displays function traces like 'live' subcommand or
trace-cmd does.  It's not useful than them at this time but it could
be improved soon.

'perf ftrace report' displays usual 'perf report' style output from
the function trace data.  You can see which function is called most
frequently for example.  Currently it uses 1 as a period value for
each entry but we might use funcgraph_exit->calltime to get proper
overhead later.

Example below:

  # perf ftrace record sleep 0.1
  # ls -l perf.data.dir
  total 5568
  -rw-r--r--. 1 root root 3514375 Apr 23 16:43 perf.header
  -rw-r--r--. 1 root root   90112 Apr 23 16:43 trace-cpu0.buf
  -rw-r--r--. 1 root root       0 Apr 23 16:43 trace-cpu1.buf
  -rw-r--r--. 1 root root 2093056 Apr 23 16:43 trace-cpu2.buf
  -rw-r--r--. 1 root root       0 Apr 23 16:43 trace-cpu3.buf

  # perf ftrace show
  overriding event (11) ftrace:funcgraph_entry with new print handler
  overriding event (10) ftrace:funcgraph_exit with new print handler
           sleep-11573 [000] 717758.728678862: funcgraph_entry:     
finish_task_switch() {
           sleep-11573 [000] 717758.728682155: funcgraph_exit:       }
           sleep-11573 [000] 717758.728683099: funcgraph_entry:     
finish_wait() {
           sleep-11573 [000] 717758.728683617: funcgraph_exit:       }
           sleep-11573 [000] 717758.728683993: funcgraph_entry:     
pipe_lock() {
           sleep-11573 [000] 717758.728684425: funcgraph_entry:       
pipe_lock_nested.isra.
           sleep-11573 [000] 717758.728684863: funcgraph_entry:         
mutex_lock() {
           sleep-11573 [000] 717758.728685239: funcgraph_entry:           
_cond_resched() {
           sleep-11573 [000] 717758.728685807: funcgraph_exit:            
}
           sleep-11573 [000] 717758.728686296: funcgraph_exit:           }
           sleep-11573 [000] 717758.728686757: funcgraph_exit:         }
           sleep-11573 [000] 717758.728687529: funcgraph_exit:       }
           sleep-11573 [000] 717758.728688608: funcgraph_entry:     
mutex_unlock() {
           sleep-11573 [000] 717758.728689343: funcgraph_exit:       }
           sleep-11573 [000] 717758.728690685: funcgraph_entry:     
__audit_syscall_exit() {
           sleep-11573 [000] 717758.728691499: funcgraph_entry:       
path_put() {
           sleep-11573 [000] 717758.728692147: funcgraph_entry:         
dput() {
           sleep-11573 [000] 717758.728692845: funcgraph_exit:           }
           sleep-11573 [000] 717758.728693380: funcgraph_entry:         
mntput() {
           sleep-11573 [000] 717758.728694021: funcgraph_exit:           }
           sleep-11573 [000] 717758.728694520: funcgraph_exit:         }
           sleep-11573 [000] 717758.728695005: funcgraph_entry:       
unroll_tree_refs() {
           sleep-11573 [000] 717758.728695659: funcgraph_exit:         }
           sleep-11573 [000] 717758.728696301: funcgraph_entry:       
kfree() {
           sleep-11573 [000] 717758.728697085: funcgraph_exit:         }
           sleep-11573 [000] 717758.728697916: funcgraph_exit:       }


  # perf ftrace report
  # ========
  # captured on: Tue Apr 23 16:43:52 2013
  # hostname : sejong.aot.lge.com
  # os release : 3.6.11-5.fc17.x86_64
  # perf version : 3.9.rc8.gceb5f8
  # arch : x86_64
  # nrcpus online : 12
  # nrcpus avail : 12
  # cpudesc : Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz
  # cpuid : GenuineIntel,6,45,7
  # total memory : 32901952 kB
  # cmdline : /home/namhyung/project/linux/tools/perf/perf ftrace record
sleep 0.1 
  # event : name = ftrace:funcgraph_entry, type = 2, config = 0xb, config1
= 0x0, config2 = 0x0
  # event : name = ftrace:funcgraph_exit, type = 2, config = 0xa, config1 =
0x0, config2 = 0x0,
  # HEADER_CPU_TOPOLOGY info available, use -I to display
  # HEADER_NUMA_TOPOLOGY info available, use -I to display
  # ========
  #
  # Samples: 22K of event 'ftrace:funcgraph_entry'
  # Event count (approx.): 22433
  #
  # Overhead  Command      Shared Object                          Symbol
  # ........  .......  .................  ..............................
  #
       7.90%    sleep  [kernel.kallsyms]  [k] _cond_resched                
            
       4.57%    sleep  [kernel.kallsyms]  [k] ebitmap_get_bit              
            
       3.50%    sleep  [kernel.kallsyms]  [k] __phys_addr                  
            
       3.12%    sleep  [kernel.kallsyms]  [k] _raw_spin_lock               
            
       3.09%    sleep  [kernel.kallsyms]  [k] kmem_cache_free              
            
       2.93%    sleep  [kernel.kallsyms]  [k] __slab_free                  
            
       2.86%    sleep  [kernel.kallsyms]  [k] __tlb_remove_page            
            
       2.35%    sleep  [kernel.kallsyms]  [k] vm_normal_page               
            
       2.33%    sleep  [kernel.kallsyms]  [k] page_remove_rmap             
            
       1.87%    sleep  [kernel.kallsyms]  [k] mutex_unlock               



You can get it from 'perf/ftrace-v1' branch on my tree at:

  git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git


Also note that this patchset is based on my previous work [1][2].

Any comments are welcome, thanks,
Namhyung


[1] https://lkml.org/lkml/2013/4/11/194
[2] https://lkml.org/lkml/2013/4/15/13


Namhyung Kim (14):
  perf util: Move debugfs/tracing helper functions to util.c
  perf util: Use evsel->name to get tracepoint_paths
  perf util: Save pid-cmdline mapping into tracing header
  perf util: Add more debug message on failure path
  perf tools: Introduce new 'ftrace' tool
  perf ftrace: Add support for --pid option
  perf ftrace: Add support for -a and -C option
  perf ftrace: Split "live" sub-command
  perf ftrace: Add 'record' sub-command
  perf ftrace: Add 'show' sub-command
  perf ftrace: Add 'report' sub-command
  perf ftrace: Use pager for displaying result
  perf ftrace: Cleanup using ftrace_setup/teardown()
  perf tools: Add document for perf-ftrace command

 tools/perf/Documentation/perf-ftrace.txt |  114 ++
 tools/perf/Makefile                      |    1 +
 tools/perf/builtin-ftrace.c              | 1665
++++++++++++++++++++++++++++++
 tools/perf/builtin.h                     |    1 +
 tools/perf/command-list.txt              |    1 +
 tools/perf/perf.c                        |    1 +
 tools/perf/util/header.c                 |    4 +-
 tools/perf/util/trace-event-info.c       |  111 +-
 tools/perf/util/trace-event-parse.c      |   17 +
 tools/perf/util/trace-event-read.c       |   77 +-
 tools/perf/util/trace-event.h            |    1 +
 tools/perf/util/util.c                   |   59 ++
 tools/perf/util/util.h                   |    3 +
 13 files changed, 1981 insertions(+), 74 deletions(-)
 create mode 100644 tools/perf/Documentation/perf-ftrace.txt
 create mode 100644 tools/perf/builtin-ftrace.c

-- 
1.7.11.7
 
CD: 3ms