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2018-11-21perf jvmti: Separate jvmti cmlr checkJiri Olsa
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 <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ben Gainey <ben.gainey@arm.com> Cc: Gustavo Luiz Duarte <gduarte@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/20181121154341.21521-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-11-05perf tools: Fix undefined symbol scnprintf in libperf-jvmti.soGustavo Romero
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 <gromero@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> 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 <acme@redhat.com>
2018-07-11perf tools: Fix compilation errors on gcc8Jiri Olsa
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 <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20180702134202.17745-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-12-18perf jvmti: Generate correct debug information for inlined codeBen Gainey
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 -u Before 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 <ben.gainey@arm.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Stephane Eranian <eranian@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ben Gainey <ben.gainey@arm.com> Cc: Colin King <colin.king@canonical.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 598b7c6919c7 ("perf jit: add source line info support") Link: http://lkml.kernel.org/r/20171122182541.d25599a3eb1ada3480d142fa@arm.com Signed-off-by: Kim Phillips <kim.phillips@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman
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 <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-27perf jit: fix typo: "incalid" -> "invalid"Colin Ian King
Trivial fix to typo in jvmti_close() warnx warning message. Signed-off-by: Colin King <colin.king@canonical.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/20170627124917.19151-1-colin.king@canonical.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-19perf tools: Use __maybe_unused consistentlyArnaldo Carvalho de Melo
Instead of defining __unused or redefining __maybe_unused. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-4eleto5pih31jw1q4dypm9pf@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-11-14perf kvmti: Remove unused Makefile fileJiri Olsa
Now when jvmti compilation is plugged into Makefile.perf, there's no need for this makefile. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Stephane Eranian <eranian@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: William Cohen <wcohen@redhat.com> Link: http://lkml.kernel.org/r/20161112121016.GA17194@krava Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-11-14perf jvmti: Plug compilation into perf buildJiri Olsa
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.so Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Tested-by: Stephane Eranian <eranian@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: William Cohen <wcohen@redhat.com> Link: http://lkml.kernel.org/r/1478093749-5602-4-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-10-24perf jit: Remove unecessary padding in jitdump fileStephane Eranian
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 <eranian@google.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1476356383-30100-4-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-10-24perf jit: Improve error messages from JVMTIStephane Eranian
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 <eranian@google.com> Cc: Anton Blanchard <anton@ozlabs.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> 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 <acme@redhat.com>
2016-10-17perf jit: Fix build issue on UbuntuAnton Blanchard
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 <anton@samba.org> Reviewed-by: Stephane Eranian <eranian@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1476325243-15788-1-git-send-email-anton@ozlabs.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-18perf jit: Remove some no-op error handlingDan Carpenter
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 <dan.carpenter@oracle.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: kernel-janitors@vger.kernel.org Link: http://lkml.kernel.org/r/20160715210836.GB19522@mwanda Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-18perf jit: Add missing curly bracesDan Carpenter
It doesn't change the runtime behavior, but my static checker complains that curly braces were intended. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: kernel-janitors@vger.kernel.org Link: http://lkml.kernel.org/r/20160715210712.GA19522@mwanda Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-01perf jit: Add support for using TSC as a timestampAdrian Hunter
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 <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Cc: Wang Nan <wangnan0@huawei.com> 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 <acme@redhat.com>
2016-02-25perf jvmti: improve error message in MakefileStephane Eranian
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 <eranian@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1456378056-18812-1-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-16perf jvmti: Add check for java alternatives cmd in MakefileStephane Eranian
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 <eranian@google.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1455604661-9357-1-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-05perf jit: add source line info supportStephane Eranian
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 <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/1448874143-7269-5-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-02-05perf tools: add JVMTI agent libraryStephane Eranian
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 $ 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: Stephane Eranian <eranian@google.com> Tested-by: Arnaldo 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: Arnaldo Carvalho de Melo <acme@redhat.com>