30 May, 2020
1 commit
-
For each PC/BCI pair in the JVMTI compiler inlining record table, the
jitdump plugin emits debug line table entries for every source line in
the method preceding that BCI. Instead only emit one source line per
PC/BCI pair. Reported by Ian Rogers. This reduces the .dump size for
SPECjbb from ~230MB to ~40MB.Signed-off-by: Nick Gasson
Acked-by: Ian Rogers
Cc: Jiri Olsa
Cc: Peter Zijlstra
Cc: Stephane Eranian
Link: http://lore.kernel.org/lkml/20200528054049.13662-1-nick.gasson@arm.com
Signed-off-by: Arnaldo Carvalho de Melo
28 May, 2020
2 commits
-
If the Java sources are compiled with -g:none to disable debug
information the perf JVMTI plugin reports a lot of errors like:java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATION
java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATION
java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATION
java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATION
java: GetLineNumberTable failed with JVMTI_ERROR_ABSENT_INFORMATIONInstead if GetLineNumberTable returns JVMTI_ERROR_ABSENT_INFORMATION
simply skip emitting line number information for that method. Unlike the
previous patch these errors don't affect the jitdump generation, they
just generate a lot of noise.Similarly for native methods which also don't have line tables.
Signed-off-by: Nick Gasson
Reviewed-by: Ian Rogers
Tested-by: Ian Rogers
Cc: Alexander Shishkin
Cc: Jiri Olsa
Cc: Mark Rutland
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lore.kernel.org/lkml/20200427061520.24905-3-nick.gasson@arm.com
[ Moved || operator to the end of the line, not at the start of 2nd if condition ]
Signed-off-by: Arnaldo Carvalho de Melo -
If a Java class is compiled with -g:none to omit debug information, the
JVMTI plugin won't write jitdump entries for any method in this class
and prints a lot of errors like:java: GetSourceFileName failed with JVMTI_ERROR_ABSENT_INFORMATION
The call to GetSourceFileName is used to derive the file name `fn`, but
this value is not actually used since commit ca58d7e64bdf ("perf jvmti:
Generate correct debug information for inlined code") which moved the
file name lookup into fill_source_filenames(). So the call to
GetSourceFileName and related code can be safely removed.Signed-off-by: Nick Gasson
Reviewed-by: Ian Rogers
Tested-by: Ian Rogers
Cc: Alexander Shishkin
Cc: Jiri Olsa
Cc: Mark Rutland
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lore.kernel.org/lkml/20200427061520.24905-2-nick.gasson@arm.com
Signed-off-by: Arnaldo Carvalho de Melo
15 Oct, 2019
1 commit
-
The build of file libperf-jvmti.so succeeds but the resulting
object fails to load:# ~/linux/tools/perf/perf record -k mono -- java \
-XX:+PreserveFramePointer \
-agentpath:/root/linux/tools/perf/libperf-jvmti.so \
hog 100000 123450
Error occurred during initialization of VM
Could not find agent library /root/linux/tools/perf/libperf-jvmti.so
in absolute path, with error:
/root/linux/tools/perf/libperf-jvmti.so: undefined symbol: _ctypeAdd the missing _ctype symbol into the build script.
Fixes: 79743bc927f6 ("perf jvmti: Link against tools/lib/string.o to have weak strlcpy()")
Signed-off-by: Thomas Richter
Cc: Heiko Carstens
Cc: Vasily Gorbik
Link: http://lore.kernel.org/lkml/20191008093841.59387-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo
20 Sep, 2019
1 commit
-
That is needed in systems such some S/390 distros.
$ readelf -s /tmp/build/perf/jvmti/jvmti-in.o | grep strlcpy
452: 0000000000002990 125 FUNC WEAK DEFAULT 119 strlcpy
$Thanks to Jiri Olsa for fixing up my initial stab at this, I forgot how
Makefiles are picky about spaces versus tabs.Reported-by: Thomas Richter
Cc: Adrian Hunter
Cc: Andreas Krebbel
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Sergey Melnikov
Link: https://lkml.kernel.org/n/tip-x8vg9sffgb2t1tzqmhkrulh7@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
18 Jun, 2019
1 commit
-
Laura reported that the perf build failed in fedora when we got a glibc
that provides gettid(), which I reproduced using fedora rawhide with the
glibc-devel-2.29.9000-26.fc31.x86_64 package.Add a feature check to avoid providing a gettid() helper in such
systems.On a fedora rawhide system with this patch applied we now get:
[root@7a5f55352234 perf]# grep gettid /tmp/build/perf/FEATURE-DUMP
feature-gettid=1
[root@7a5f55352234 perf]# cat /tmp/build/perf/feature/test-gettid.make.output
[root@7a5f55352234 perf]# ldd /tmp/build/perf/feature/test-gettid.bin
linux-vdso.so.1 (0x00007ffc6b1f6000)
libc.so.6 => /lib64/libc.so.6 (0x00007f04e0a74000)
/lib64/ld-linux-x86-64.so.2 (0x00007f04e0c47000)
[root@7a5f55352234 perf]# nm /tmp/build/perf/feature/test-gettid.bin | grep -w gettid
U gettid@@GLIBC_2.30
[root@7a5f55352234 perf]#While on a fedora:29 system:
[acme@quaco perf]$ grep gettid /tmp/build/perf/FEATURE-DUMP
feature-gettid=0
[acme@quaco perf]$ cat /tmp/build/perf/feature/test-gettid.make.output
test-gettid.c: In function ‘main’:
test-gettid.c:8:9: error: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Werror=implicit-function-declaration]
return gettid();
^~~~~~
getgid
cc1: all warnings being treated as errors
[acme@quaco perf]$Reported-by: Laura Abbott
Tested-by: Laura Abbott
Acked-by: Jiri Olsa
Cc: Adrian Hunter
Cc: Florian Weimer
Cc: Namhyung Kim
Cc: Stephane Eranian
Link: https://lkml.kernel.org/n/tip-yfy3ch53agmklwu9o7rlgf9c@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
05 Jun, 2019
1 commit
-
We are getting false positive gcc warning when we compile with gcc9 (9.1.1):
CC jvmti/libjvmti.o
In file included from /usr/include/string.h:494,
from jvmti/libjvmti.c:5:
In function ‘strncpy’,
inlined from ‘copy_class_filename.constprop’ at jvmti/libjvmti.c:166:3:
/usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound depends on the length of the source argument [-Werror=stringop-overflow=]
106 | return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
jvmti/libjvmti.c: In function ‘copy_class_filename.constprop’:
jvmti/libjvmti.c:165:26: note: length computed here
165 | size_t file_name_len = strlen(file_name);
| ^~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errorsAs per Arnaldo's suggestion use strlcpy(), which does the same thing and keeps
gcc silent.Suggested-by: Arnaldo Carvalho de Melo
Signed-off-by: Jiri Olsa
Cc: Alexander Shishkin
Cc: Ben Gainey
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: Stephane Eranian
Link: http://lkml.kernel.org/r/20190531131321.GB1281@krava
Signed-off-by: Arnaldo Carvalho de Melo
22 Nov, 2018
1 commit
-
The Compiled Method Load Record (cmlr) is JDK specific interface to
access JVM stack info. This makes the jvmti agent code not compile under
another jdk, which does not support that.Separating jvmti cmlr check into special feature check, and adding
HAVE_JVMTI_CMLR macro to indicate that.Mark cmlr code in jvmti/libjvmti.c with HAVE_JVMTI_CMLR, so we can
compile it on system without cmlr support.This change makes the jvmti compile with java-1.8.0-ibm package. It's
without the line numbers support, but the rest works.Adding NO_JVMTI_CMLR compile variable for testing.
Signed-off-by: Jiri Olsa
Cc: Alexander Shishkin
Cc: Ben Gainey
Cc: Gustavo Luiz Duarte
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: Stephane Eranian
Link: http://lkml.kernel.org/r/20181121154341.21521-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
06 Nov, 2018
1 commit
-
Currently jvmti agent can not be used because function scnprintf is not
present in the agent libperf-jvmti.so. As a result the JVM when using
such agent to record JITed code profiling information will fail on
looking up scnprintf:java: symbol lookup error: lib/libperf-jvmti.so: undefined symbol: scnprintf
This commit fixes that by reverting to the use of snprintf, that can be
looked up, instead of scnprintf, adding a proper check for the returned
value in order to print a better error message when the jitdump file
pathname is too long. Checking the returned value also helps to comply
with some recent gcc versions, like gcc8, which will fail due to
truncated writing checks related to the -Werror=format-truncation= flag.Signed-off-by: Gustavo Romero
Acked-by: Jiri Olsa
LPU-Reference: 1541117601-18937-2-git-send-email-gromero@linux.vnet.ibm.com
Link: https://lkml.kernel.org/n/tip-mvpxxxy7wnzaj74cq75muw3f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
11 Jul, 2018
1 commit
-
We are getting following warnings on gcc8 that break compilation:
$ make
CC jvmti/jvmti_agent.o
jvmti/jvmti_agent.c: In function ‘jvmti_open’:
jvmti/jvmti_agent.c:252:35: error: ‘/jit-’ directive output may be truncated \
writing 5 bytes into a region of size between 1 and 4096 [-Werror=format-truncation=]
snprintf(dump_path, PATH_MAX, "%s/jit-%i.dump", jit_path, getpid());There's no point in checking the result of snprintf call in
jvmti_open, the following open call will fail in case the
name is mangled or too long.Using tools/lib/ function scnprintf that touches the return value from
the snprintf() calls and thus get rid of those warnings.$ make DEBUG=1
CC arch/x86/util/perf_regs.o
arch/x86/util/perf_regs.c: In function ‘arch_sdt_arg_parse_op’:
arch/x86/util/perf_regs.c:229:4: error: ‘strncpy’ output truncated before terminating nul
copying 2 bytes from a string of the same length [-Werror=stringop-truncation]
strncpy(prefix, "+0", 2);
^~~~~~~~~~~~~~~~~~~~~~~~Using scnprintf instead of the strncpy (which we know is safe in here)
to get rid of that warning.Signed-off-by: Jiri Olsa
Cc: Alexander Shishkin
Cc: David Ahern
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/20180702134202.17745-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
18 Dec, 2017
1 commit
-
tools/perf/jvmti is broken in so far as it generates incorrect debug
information. Specifically it attributes all debug lines to the original
method being output even in the case that some code is being inlined
from elsewhere. This patch fixes the issue.To test (from within linux/tools/perf):
export JDIR=/usr/lib/jvm/java-8-openjdk-amd64/
make
cat << __EOF > Test.java
public class Test
{
private StringBuilder b = new StringBuilder();private void loop(int i, String... args)
{
for (String a : args)
b.append(a);long hc = b.hashCode() * System.nanoTime();
b = new StringBuilder();
b.append(hc);System.out.printf("Iteration %d = %d\n", i, hc);
}public void run(String... args)
{
for (int i = 0; i < 10000; ++i)
{
loop(i, args);
}
}public static void main(String... args)
{
Test t = new Test();
t.run(args);
}
}
__EOF
$JDIR/bin/javac Test.java
./perf record -F 10000 -g -k mono $JDIR/bin/java -agentpath:`pwd`/libperf-jvmti.so Test
./perf inject --jit -i perf.data -o perf.data.jitted
./perf annotate -i perf.data.jitted --stdio | grep Test\.java: | sort -uBefore this patch, Test.java line numbers get reported that are greater
than the number of lines in the Test.java file. They come from the
source file of the inlined function, e.g. java/lang/String.java:1085.
For further validation one can examine those lines in the JDK source
distribution and confirm that they map to inlined functions called by
Test.java.After this patch, the filename of the inlined function is output
rather than the incorrect original source filename.Signed-off-by: Ben Gainey
Tested-by: Arnaldo Carvalho de Melo
Tested-by: Stephane Eranian
Cc: Alexander Shishkin
Cc: Ben Gainey
Cc: Colin King
Cc: Darren Hart
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Fixes: 598b7c6919c7 ("perf jit: add source line info support")
Link: http://lkml.kernel.org/r/20171122182541.d25599a3eb1ada3480d142fa@arm.com
Signed-off-by: Kim Phillips
Signed-off-by: Arnaldo Carvalho de Melo
02 Nov, 2017
1 commit
-
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.By default all files without license information are under the default
license of the kernel, which is GPL version 2.Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
27 Jun, 2017
1 commit
-
Trivial fix to typo in jvmti_close() warnx warning message.
Signed-off-by: Colin King
Cc: Alexander Shishkin
Cc: Dan Carpenter
Cc: Peter Zijlstra
Cc: Stephane Eranian
Link: http://lkml.kernel.org/r/20170627124917.19151-1-colin.king@canonical.com
Signed-off-by: Arnaldo Carvalho de Melo
20 Jun, 2017
1 commit
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Instead of defining __unused or redefining __maybe_unused.
Cc: Adrian Hunter
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Wang Nan
Link: http://lkml.kernel.org/n/tip-4eleto5pih31jw1q4dypm9pf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
14 Nov, 2016
2 commits
-
Now when jvmti compilation is plugged into Makefile.perf, there's no
need for this makefile.Signed-off-by: Jiri Olsa
Acked-by: Stephane Eranian
Cc: Andi Kleen
Cc: David Ahern
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: William Cohen
Link: http://lkml.kernel.org/r/20161112121016.GA17194@krava
Signed-off-by: Arnaldo Carvalho de Melo -
Compile jvmti agent as part of the perf build. The agent library is
called libperf-jvmti.so and is installed in default place together with
other files:$ make libperf-jvmti.so
BUILD: Doing 'make -j4' parallel build
...
CC jvmti/libjvmti.o
CC jvmti/jvmti_agent.o
LD jvmti/jvmti-in.o
LINK libperf-jvmti.so$ make DESTDIR=/tmp/krava/ install-bin
...
$ find /tmp/krava/ | grep libperf
/tmp/krava/lib64/libperf-jvmti.so
/tmp/krava/lib64/libperf-gtk.soSigned-off-by: Jiri Olsa
Tested-by: Arnaldo Carvalho de Melo
Tested-by: Stephane Eranian
Cc: Andi Kleen
Cc: David Ahern
Cc: Namhyung Kim
Cc: Peter Zijlstra
Cc: William Cohen
Link: http://lkml.kernel.org/r/1478093749-5602-4-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo
24 Oct, 2016
2 commits
-
This patch removes all the string padding generated in the jitdump file.
They are not necessary and were adding unnecessary complexity. Modern
processors can handle unaligned accesses quite well. The perf.data/
jitdump file are always post-processed, no need to add extra complexity
for no real gain.Signed-off-by: Stephane Eranian
Cc: Anton Blanchard
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/1476356383-30100-4-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo -
This patch improves the usefulness of error messages generated by the
JVMTI interfac.e This can help identify the root cause of a problem by
printing the actual error code. The patch adds a new helper function
called print_error().Signed-off-by: Stephane Eranian
Cc: Anton Blanchard
Cc: Jiri Olsa
Cc: Namhyung Kim
Cc: Nilay Vaish
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/1476356383-30100-2-git-send-email-eranian@google.com
[ Handle failure to convert numeric error to a string in print_error() ]
Signed-off-by: Arnaldo Carvalho de Melo
17 Oct, 2016
1 commit
-
When building on Ubuntu 16.04, I get the following error:
Makefile:49: *** the openjdk development package appears to me missing, install and try again. Stop.
The problem is that update-java-alternatives has multiple spaces between
fields, and cut treats each space as a new delimiter:java-1.8.0-openjdk-ppc64el 1081 /usr/lib/jvm/java-1.8.0-openjdk-ppc64el
Fix this by using awk, which handles this fine.
Signed-off-by: Anton Blanchard
Reviewed-by: Stephane Eranian
Cc: Alexander Shishkin
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/1476325243-15788-1-git-send-email-anton@ozlabs.org
Signed-off-by: Arnaldo Carvalho de Melo
18 Jul, 2016
2 commits
-
The 'info.e_machine' struct member is an uint16_t so 'm' is never less
than zero. It looks like this was maybe left over code from earlier
versions so I've just removed it.Signed-off-by: Dan Carpenter
Cc: Adrian Hunter
Cc: Alexander Shishkin
Cc: Peter Zijlstra
Cc: Stephane Eranian
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/20160715210836.GB19522@mwanda
Signed-off-by: Arnaldo Carvalho de Melo -
It doesn't change the runtime behavior, but my static checker complains
that curly braces were intended.Signed-off-by: Dan Carpenter
Cc: Adrian Hunter
Cc: Alexander Shishkin
Cc: Peter Zijlstra
Cc: Stephane Eranian
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/20160715210712.GA19522@mwanda
Signed-off-by: Arnaldo Carvalho de Melo
02 Apr, 2016
1 commit
-
Intel PT uses TSC as a timestamp, so add support for using TSC instead
of the monotonic clock. Use of TSC is selected by an environment
variable "JITDUMP_USE_ARCH_TIMESTAMP" and flagged in the jitdump file
with flag JITDUMP_FLAGS_ARCH_TIMESTAMP.Signed-off-by: Adrian Hunter
Cc: Alexander Shishkin
Cc: He Kuang
Cc: Jiri Olsa
Cc: Josh Poimboeuf
Cc: Peter Zijlstra
Cc: Stephane Eranian
Cc: Sukadev Bhattiprolu
Cc: Wang Nan
Link: http://lkml.kernel.org/r/1457426330-30226-1-git-send-email-adrian.hunter@intel.com
[ Added the fixup from He Kuang to make it build on other arches, ]
[ such as aarch64, to avoid inserting this bisectiong breakage upstream ]
Link: http://lkml.kernel.org/r/1459482572-129494-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo
25 Feb, 2016
1 commit
-
This patch improves the error message given by jvmti Makefile when the
alternatives command cannot be found. It now suggests the user locates
the root of their Java installation and pass it with JDIR=Signed-off-by: Stephane Eranian
Cc: Adrian Hunter
Cc: Andi Kleen
Cc: Jiri Olsa
Cc: Kan Liang
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/1456378056-18812-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo
17 Feb, 2016
1 commit
-
This patch modifies the jvmti makefile to check if the
/usr/sbin/java-update-alternatives utility is present. If so, then use
it, if not then use the altenatives command.This helps handle the difference between Ubuntu and Fedora Linux
distributions.Signed-off-by: Stephane Eranian
Tested-by: Arnaldo Carvalho de Melo
Cc: Adrian Hunter
Cc: Andi Kleen
Cc: David Ahern
Cc: Jiri Olsa
Cc: Kan Liang
Cc: Namhyung Kim
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/1455604661-9357-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo
05 Feb, 2016
2 commits
-
This patch adds source line information support to perf for jitted code.
The source line info must be emitted by the runtime, such as JVMTI.
Perf injects extract the source line info from the jitdump file and adds
the corresponding .debug_lines section in the ELF image generated for
each jitted function.The source line enables matching any address in the profile with a
source file and line number.The improvement is visible in perf annotate with the source code
displayed alongside the assembly code.The dwarf code leverages the support from OProfile which is also
released under GPLv2. Copyright 2007 OProfile authors.Signed-off-by: Stephane Eranian
Cc: Adrian Hunter
Cc: Andi Kleen
Cc: Carl Love
Cc: David Ahern
Cc: Jiri Olsa
Cc: John McCutchan
Cc: Namhyung Kim
Cc: Pawel Moll
Cc: Peter Zijlstra
Cc: Sonny Rao
Cc: Sukadev Bhattiprolu
Link: http://lkml.kernel.org/r/1448874143-7269-5-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo -
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:34f439278cef ("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
$ makeThen, 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.soSymbol 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/ae54a2ebc3ecf0ba547bfc8cabdea1519df5203fNote: 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.jittedLooking 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_threadSigned-off-by: Stephane Eranian
Tested-by: Arnaldo Carvalho de Melo
Cc: Adrian Hunter
Cc: Andi Kleen
Cc: Carl Love
Cc: David Ahern
Cc: Jiri Olsa
Cc: John McCutchan
Cc: Namhyung Kim
Cc: Pawel Moll
Cc: Peter Zijlstra
Cc: Sonny Rao
Cc: Sukadev Bhattiprolu
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: Arnaldo Carvalho de Melo