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  1. 05 Feb, 2016 6 commits
    • Stephane Eranian's avatar
      perf tools: add JVMTI agent library · 209045ad
      Stephane Eranian authored 
      This is a standalone JVMTI library to help  profile Java jitted code with perf
record/perf report. The library is not installed or compiled automatically by
perf Makefile. It is not used directly by perf. It is arch agnostic and has
been tested on X86 and ARM. It needs to be used with a Java runtime, such as
OpenJDK, as follows:

  $ java -agentpath:libjvmti.so .......

See the "Committer Notes" below on how to build it.

When used this way, java will generate a jitdump binary file in
$HOME/.debug/java/jit/java-jit-*

This binary dump file contains information to help symbolize and
annotate jitted code.

The jitdump information must be injected into the perf.data file
using:

  $ perf inject --jit -i perf.data -o perf.data.jitted

This injects the MMAP records to cover the jitted code and also generates
one ELF image for each jitted function. The ELF images are created in the
same subdir as the jitdump file. The MMAP records point there too.

Then, to visualize the function or asm profile, simply use the regular
perf commands:

  $ perf report -i perf.data.jitted

or

  $ perf annotate -i perf.data.jitted

JVMTI agent code adapted from the OProfile's opagent code.

This version of the JVMTI agent is using the CLOCK_MONOTONIC as the time
source to timestamp jit samples. To correlate with perf_events samples,
it needs to run on kernel 4.0.0-rc5+ or later with the following commit
from Peter Zijlstra:

  34f43927 ("perf: Add per event clockid support")

With this patch recording jitted code is done as follows:

   $ perf record -k mono -- java -agentpath:libjvmti.so .......

 --------------------------------------------------------------------------

Committer Notes:

Extended testing instructions:

  $ cd tools/perf/jvmti/
  $ dnf install java-devel
  $ make

Then, create some simple java stuff to record some samples:

  $ cat hello.java
  public class hello {
	public static void main(String[] args) {
                 System.out.println("Hello, World");
       	}
  }
  $ javac hello.java
  $ java hello
  Hello, World
  $

And then record it using this jvmti thing:

  $ perf record -k mono java -agentpath:/home/acme/git/linux/tools/perf/jvmti/libjvmti.so hello
  java: jvmti: jitdump in /home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jit-1908.dump
  Hello, World
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.030 MB perf.data (268 samples) ]
  $

Now lets insert the PERF_RECORD_MMAP2 records to point jitted mmaps to
files created by the agent:

  $ perf inject --jit -i perf.data -o perf.data.jitted

And finally see that it did its job:

  $ perf report -D -i perf.data.jitted | grep PERF_RECORD_MMAP2 | tail -5
  79197149129422 0xfe10 [0xa0]: PERF_RECORD_MMAP2 1908/1923: [0x7f172428bd60(0x80) @ 0x40 fd:02 1840554 1]: --xs /home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jitted-1908-283.so
  79197149235701 0xfeb0 [0xa0]: PERF_RECORD_MMAP2 1908/1923: [0x7f172428ba60(0x180) @ 0x40 fd:02 1840555 1]: --xs /home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jitted-1908-284.so
  79197149250558 0xff50 [0xa0]: PERF_RECORD_MMAP2 1908/1923: [0x7f172428b860(0x180) @ 0x40 fd:02 1840556 1]: --xs /home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jitted-1908-285.so
  79197149714746 0xfff0 [0xa0]: PERF_RECORD_MMAP2 1908/1923: [0x7f172428b660(0x180) @ 0x40 fd:02 1840557 1]: --xs /home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jitted-1908-286.so
  79197149806558 0x10090 [0xa0]: PERF_RECORD_MMAP2 1908/1923: [0x7f172428b460(0x180) @ 0x40 fd:02 1840558 1]: --xs /home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jitted-1908-287.so
  $

So:

  $ perf report -D -i perf.data | grep PERF_RECORD_MMAP2 | wc -l
  Failed to open /tmp/perf-1908.map, continuing without symbols
  21
  $ perf report -D -i perf.data.jitted | grep PERF_RECORD_MMAP2 | wc -l
  307
  $ echo $((307 - 21))
  286
  $

286 extra PERF_RECORD_MMAP2 records.

All for thise tiny, with just one function, ELF files:

  $ file /home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jitted-1908-9.so
  /home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jitted-1908-9.so: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), corrupted program header size, BuildID[sha1]=ae54a2ebc3ecf0ba547bfc8cabdea1519df5203f, not stripped
  $ readelf -sw /home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jitted-1908-9.so

  Symbol table '.symtab' contains 2 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
     0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 0000000000000040     9 FUNC    LOCAL  DEFAULT    1 atomic_cmpxchg_long
  $

Inserted into the build-id cache:

  $ ls -la ~/.debug/.build-id/ae/54a2ebc3ecf0ba547bfc8cabdea1519df5203f
  lrwxrwxrwx. 1 acme acme 111 Feb  5 11:30 /home/acme/.debug/.build-id/ae/54a2ebc3ecf0ba547bfc8cabdea1519df5203f -> ../../home/acme/.debug/jit/java-jit-20160205.XXWIEDls/jitted-1908-9.so/ae54a2ebc3ecf0ba547bfc8cabdea1519df5203f

Note: check why 'file' reports that 'corrupted program header size'.

With a stupid java hog to do some profiling:

$ cat hog.java
  public class hog {
	private static double do_something_else(int i) {
		double total = 0;
		while (i > 0) {
			total += Math.log(i--);
		}
		return total;
	}
	private static double do_something(int i) {
		double total = 0;
		while (i > 0) {
			total += Math.sqrt(i--) + do_something_else(i / 100);
		}
		return total;
	}
	public static void main(String[] args) {
		System.out.println(String.format("%s=%f & %f", args[0],
				   do_something(Integer.parseInt(args[0])),
				   do_something_else(Integer.parseInt(args[1]))));
	}
  }
  $ javac hog.java
  $ perf record -F 10000 -g -k mono java -agentpath:/home/acme/git/linux/tools/perf/jvmti/libjvmti.so hog 100000 2345000
  java: jvmti: jitdump in /home/acme/.debug/jit/java-jit-20160205.XX4sqd14/jit-8670.dump
  100000=291561592.669602 & 32050989.778714
  [ perf record: Woken up 6 times to write data ]
  [ perf record: Captured and wrote 1.536 MB perf.data (12538 samples) ]
  $ perf inject --jit -i perf.data -o perf.data.jitted

Looking at the 'perf report' TUI, at one expanded callchain leading
to the jitted code:

  $ perf report --no-children -i perf.data.jitted

Samples: 12K of event 'cycles:pp', Event count (approx.): 3829569932
  Overhead  Comm  Shared Object       Symbol
-   93.38%  java  jitted-8670-291.so  [.] class hog.do_something_else(int)
     class hog.do_something_else(int)
   - Interpreter
      - 75.86% call_stub
           JavaCalls::call_helper
           jni_invoke_static
           jni_CallStaticVoidMethod
           JavaMain
           start_thread
      - 17.52% JavaCalls::call_helper
           jni_invoke_static
           jni_CallStaticVoidMethod
           JavaMain
           start_thread
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carl Love <cel@us.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John McCutchan <johnmccutchan@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1448874143-7269-4-git-send-email-eranian@google.com
[ Made it build on fedora23, added some build/usage instructions ]
[ Check if filename != NULL in compiled_method_load_cb, fixing segfault ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      209045ad
    • Stephane Eranian's avatar
      perf inject: Add jitdump mmap injection support · 9b07e27f
      Stephane Eranian authored 
      This patch adds a --jit/-j option to perf inject.

This options injects MMAP records into the perf.data file to cover the
jitted code mmaps. It also emits ELF images for each function in the
jidump file.  Those images are created where the jitdump file is.  The
MMAP records point to that location as well.

Typical flow:

  $ perf record -k mono -- java -agentpath:libpjvmti.so java_class
  $ perf inject --jit -i perf.data -o perf.data.jitted
  $ perf report -i perf.data.jitted

Note that jitdump.h support is not limited to Java, it works with any
jitted environment modified to emit the jitdump file format, include
those where code can be jitted multiple times and moved around.

The jitdump.h format is adapted from the Oprofile project.

The genelf.c (ELF binary generation) depends on MD5 hash encoding for
the buildid. To enable this, libssl-dev must be installed. If not, then
genelf.c defaults to using urandom to generate the buildid, which is not
ideal.  The Makefile auto-detects the presence on libssl-dev.

This version mmaps the jitdump file to create a marker MMAP record in
the perf.data file. The marker is used to detect jitdump and cause perf
inject to inject the jitted mmaps and generate ELF images for jitted
functions.

In V8, the following fixes and changes were made among other things:

  -  the jidump header format include a new flags field to be used
     to carry information about the configuration of the runtime agent.
     Contributed by: Adrian Hunter <adrian.hunter@intel.com>

  - Fix mmap pgoff: MMAP event pgoff must be the offset within the ELF file
    at which the code resides.
    Contributed by: Adrian Hunter <adrian.hunter@intel.com>

  - Fix ELF virtual addresses: perf tools expect the ELF virtual addresses of dynamic
    objects to match the file offset.
    Contributed by: Adrian Hunter <adrian.hunter@intel.com>

  - JIT MMAP injection does not obey finished_round semantics. JIT MMAP injection injects all
    MMAP events in one go, so it does not obey finished_round semantics, so drop the
    finished_round events from the output perf.data file.
    Contributed by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carl Love <cel@us.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John McCutchan <johnmccutchan@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1448874143-7269-3-git-send-email-eranian@google.com
[ Moved inject.build_ids ordering bits to a separate patch, fixed the NO_LIBELF=1 build ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      9b07e27f
    • Arnaldo Carvalho de Melo's avatar
      perf inject: Make sure mmap records are ordered when injecting build_ids · 921f3fad
      Arnaldo Carvalho de Melo authored 
      To make sure the mmap records are ordered correctly and so that the
correct especially due to jitted code mmaps.

We cannot generate the buildid hit list and inject the jit mmaps (will
come right after this patch) in at the same time for now.
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carl Love <cel@us.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John McCutchan <johnmccutchan@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1448874143-7269-3-git-send-email-eranian@google.com
[ Carved out from a larger patch ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      921f3fad
    • Stephane Eranian's avatar
      perf build: Add libcrypto feature detection · 8ee46460
      Stephane Eranian authored 
      Will be used to generate build-ids in the jitdump code.
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carl Love <cel@us.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John McCutchan <johnmccutchan@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1448874143-7269-3-git-send-email-eranian@google.com
[ tools/perf/Makefile.perf comment about NO_LIBCRYPTO and added it to tests/make ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      8ee46460
    • Stephane Eranian's avatar
      perf symbols: add Java demangling support · e9c4bcdd
      Stephane Eranian authored 
      Add Java function descriptor demangling support.  Something bfd cannot
do.

Use the JAVA_DEMANGLE_NORET flag to avoid decoding the return type of
functions.
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Carl Love <cel@us.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John McCutchan <johnmccutchan@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1448874143-7269-2-git-send-email-eranian@google.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      e9c4bcdd
    • Marcin Ślusarz's avatar
      perf tools: handle spaces in file names obtained from /proc/pid/maps · 89fee59b
      Marcin Ślusarz authored 
      Steam frequently puts game binaries in folders with spaces.

Note: "(deleted)" markers are now treated as part of the file name.
Signed-off-by: default avatarMarcin Ślusarz <marcin.slusarz@gmail.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Fixes: 60648033 ("perf tools: Use sscanf for parsing /proc/pid/maps")
Link: http://lkml.kernel.org/r/20160119190303.GA17579@marcin-Inspiron-7720Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      89fee59b
  3. 04 Feb, 2016 16 commits
  5. 03 Feb, 2016 18 commits
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