[PATCH v2 0/4] perf: add support for profiling jitted code

[PATCH v2 0/4] perf: add support for profiling jitted code

[Stephane Eranian]

This patch series extends perf record/report/annotate to enable
profiling of jitted (just-in-time compiled) code. The current
perf tool provides very limited support for profiling jitted
code for some runtime environments. But the support is experimental
and cannot be used in complex environments. It relies on files
in /tmp, for instance. It does not support annotate mode or
rejitted code.

This patch series adds a better way of profiling jitted code
with the following advantages:
   - support any jitted code environment (some with modifications)
   - support Java runtime with JVMTI interface with no modifications
   - provides a portable JVMTI agent library
   - known to support V8 runtime
   - known to support DART runtime
   - supports code rejitting and movements
   - no files in /tmp
   - meta-data file is unique to each run
   - no changes to perf report/annotate

The support is based on cooperation with the runtime. For Java runtimes,
supporting the JVMTI interface, there is no change necessary. For other
runtimes, modifications are necessary to emit the meta-data necessary
to support symbolization and annotation of the samples. Those modifications
are fairly straighforward and already tested on V8 and DART.

The jit environment emits a binary dump file which contains the jitted
code (in raw format) and meta-data describing the mapping of functions.
The binary format is documented in the jitdump.h header file. It is
adapted from the OProfile jitdump format.

To enable synchronization of the runtime MMAPs with those recorded by
the kernel on behalf of the perf tool, the runtime needs to timestamp
any record in the dump file using the same time source. This second
version is using Pawell Moll's patch and David Ahern's re-packaging
on the patch which has a new POSIX clock: PERF_CLOCK. See the following
page:
   https://github.com/dsahern/linux/blob/perf-full-monty/README.ahern

Without this driver installed, records emitted by the runtime cannot
be properly synchronized (inserted in the flow on MMAPS) and symbolization
is not possible.

The current support only works when the runtime is monitored from
start to finish: perf record java --agenpath:libpfmjvmti.so my_class.

Once the run is completed, the jitdump file needs to be injected into
the perf.data file. This is accomplished by using the perf inject command.
This will also generate an ELF image for each jitted function. The
inject MMAP records will point to those ELF images. The reasoning
behind using ELF images is that it makes processing for perf report
and annotate automatic and transparent. It also makes it easier to
package and analyze on a remote machine. 

The reporting is unchanged, simply invoke perf report or perf annotate
on the modified perf.data file. The jitted code will appear symbolized
and the assembly view will display the instruction level profile!

As an added bonus, the series includes support for demangling function
signature from OpenJDK.

The current patch series does not include support for source line
information. Therefore, the source code cannot yet be displayed
in perf annotate. This will come in a later update.

Furthermore, we believe there is a way to skip the perf inject phase
and have perf report/annotate directly inject the MMAP records 
on the fly during processing of the perf.data file. Perf report would
also generate the ELF files if necessary. Such optimization, would
make using this extension seamless in system-wide mode and larger
environments. This will be added in a later update as well.

In V2, we have switchde to Pawell Moll and David Ahern posix
clock kernel module instead. We have dropped the patch which
modified the arguments to map_init() because the change was
not used. We are not printing the return type of Java methods
anymore and have made the Java demangler a separate module.
We also rebased to 3.19.0+ from tip.git.

To use the new feature:
  - compile and install the perf_posix_clock.ko module:
    - make modules (say M to PERF_CLOCK config option)
    - make modules_install;
    - modprobe perf_posix_clock
    - dmesg should say: perf_clock clock registered
  - compile perf
  - cd tools/perf/jvmti; make; install wherever is appropriate

  Example using openJDK:
   $ perf record java -agentpath:libjvmti.so my_class
   java: jvmti: jitdump in $HOME/.debug/jit/java-jit-20150207.XXL9649H/jit-6320.dump
   $ perf inject -i perf.data -j $HOME/.debug/jit/java-jit-20150207.XXL9649H/jit-6320.dump -o perf.data.jitted
   $ perf report -i perf.data.jitted

Thanks to all the contributors and testers.

Enjoy,

Stephane Eranian (4):
  perf tools: add Java demangling support
  perf inject: add jitdump mmap injection support
  perf tools: add JVMTI agent library
  clock: add perf_clock posix clock

 include/uapi/linux/time.h                |   1 +
 kernel/time/Kconfig                      |   6 +
 kernel/time/Makefile                     |   1 +
 kernel/time/perf_posix_clock.c           |  54 ++++
 tools/perf/Documentation/perf-inject.txt |  11 +
 tools/perf/Makefile.perf                 |   8 +-
 tools/perf/builtin-inject.c              | 205 ++++++++++++++
 tools/perf/jvmti/Makefile                |  70 +++++
 tools/perf/jvmti/jvmti_agent.c           | 320 +++++++++++++++++++++
 tools/perf/jvmti/jvmti_agent.h           |  23 ++
 tools/perf/jvmti/libjvmti.c              | 149 ++++++++++
 tools/perf/util/demangle-java.c          | 199 +++++++++++++
 tools/perf/util/demangle-java.h          |  10 +
 tools/perf/util/genelf.c                 | 463 +++++++++++++++++++++++++++++++
 tools/perf/util/genelf.h                 |   6 +
 tools/perf/util/jit.h                    |  27 ++
 tools/perf/util/jitdump.c                | 233 ++++++++++++++++
 tools/perf/util/jitdump.h                |  92 ++++++
 tools/perf/util/symbol-elf.c             |   3 +
 tools/perf/util/symbol.c                 |   6 +-
 20 files changed, 1885 insertions(+), 2 deletions(-)
 create mode 100644 kernel/time/perf_posix_clock.c
 create mode 100644 tools/perf/jvmti/Makefile
 create mode 100644 tools/perf/jvmti/jvmti_agent.c
 create mode 100644 tools/perf/jvmti/jvmti_agent.h
 create mode 100644 tools/perf/jvmti/libjvmti.c
 create mode 100644 tools/perf/util/demangle-java.c
 create mode 100644 tools/perf/util/demangle-java.h
 create mode 100644 tools/perf/util/genelf.c
 create mode 100644 tools/perf/util/genelf.h
 create mode 100644 tools/perf/util/jit.h
 create mode 100644 tools/perf/util/jitdump.c
 create mode 100644 tools/perf/util/jitdump.h

-- 
1.9.1

[PATCH v2 1/4] perf tools: add Java demangling support

[Stephane Eranian]

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: Stephane Eranian <eranian@google.com>
---
 tools/perf/Makefile.perf        |   2 +
 tools/perf/util/demangle-java.c | 199 ++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/demangle-java.h |  10 ++
 tools/perf/util/symbol-elf.c    |   3 +
 tools/perf/util/symbol.c        |   6 +-
 5 files changed, 219 insertions(+), 1 deletion(-)
 create mode 100644 tools/perf/util/demangle-java.c
 create mode 100644 tools/perf/util/demangle-java.h

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index aa6a504..53a44be 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -331,6 +331,7 @@ LIB_H += ui/ui.h
 LIB_H += util/data.h
 LIB_H += util/kvm-stat.h
 LIB_H += util/thread-stack.h
+LIB_H += util/demangle-java.h
 
 LIB_OBJS += $(OUTPUT)util/abspath.o
 LIB_OBJS += $(OUTPUT)util/alias.o
@@ -410,6 +411,7 @@ LIB_OBJS += $(OUTPUT)util/data.o
 LIB_OBJS += $(OUTPUT)util/tsc.o
 LIB_OBJS += $(OUTPUT)util/cloexec.o
 LIB_OBJS += $(OUTPUT)util/thread-stack.o
+LIB_OBJS += $(OUTPUT)util/demangle-java.o
 
 LIB_OBJS += $(OUTPUT)ui/setup.o
 LIB_OBJS += $(OUTPUT)ui/helpline.o
diff --git a/tools/perf/util/demangle-java.c b/tools/perf/util/demangle-java.c
new file mode 100644
index 0000000..79d5484
--- /dev/null
+++ b/tools/perf/util/demangle-java.c
@@ -0,0 +1,199 @@
+#include <sys/types.h>
+#include <stdio.h>
+#include <string.h>
+#include "util.h"
+#include "debug.h"
+#include "symbol.h"
+
+#include "demangle-java.h"
+
+enum {
+	MODE_PREFIX=0,
+	MODE_CLASS=1,
+	MODE_FUNC=2,
+	MODE_TYPE=3,
+	MODE_CTYPE=3, /* class arg */
+};
+
+#define BASE_ENT(c, n)	[c-'A']=n
+static const char *base_types['Z'-'A' + 1]={
+	BASE_ENT('B', "byte" ),
+	BASE_ENT('C', "char" ),
+	BASE_ENT('D', "double" ),
+	BASE_ENT('F', "float" ),
+	BASE_ENT('I', "int" ),
+	BASE_ENT('J', "long" ),
+	BASE_ENT('S', "short" ),
+	BASE_ENT('Z', "bool" ),
+};
+
+/*
+ * demangle Java symbol between str and end positions and stores
+ * up to maxlen characters into buf. The parser starts in mode.
+ *
+ * Use MODE_PREFIX to process entire prototype till end position
+ * Use MODE_TYPE to process return type if str starts on return type char
+ *
+ *  Return:
+ *	success: buf
+ *	error  : NULL
+ */
+static char *
+__demangle_java_sym(const char *str, const char *end, char *buf, int maxlen, int mode)
+{
+	int rlen = 0;
+	int array = 0;
+	int narg = 0;
+	const char *q;
+
+	if (!end)
+		end = str + strlen(str);
+
+	for (q = str; q != end; q++) {
+
+		if (rlen == (maxlen - 1))
+			break;
+
+		switch (*q) {
+		case 'L':
+			if (mode == MODE_PREFIX || mode == MODE_CTYPE) {
+				if (mode == MODE_CTYPE) {
+					if (narg)
+						rlen += snprintf(buf+rlen, maxlen - rlen, ", ");
+					narg++;
+				}
+				rlen += snprintf(buf+rlen, maxlen - rlen, "class ");
+				if (mode == MODE_PREFIX)
+					mode = MODE_CLASS;
+			} else
+				buf[rlen++] = *q;
+			break;
+		case 'B':
+		case 'C':
+		case 'D':
+		case 'F':
+		case 'I':
+		case 'J':
+		case 'S':
+		case 'Z':
+			if (mode == MODE_TYPE) {
+				if (narg)
+					rlen += snprintf(buf+rlen, maxlen - rlen, ", ");
+				rlen += snprintf(buf+rlen, maxlen - rlen, "%s", base_types[*q - 'A']);
+				while(array--)
+					rlen += snprintf(buf+rlen, maxlen - rlen, "[]");
+				array = 0;
+				narg++;
+			} else
+				buf[rlen++] = *q;
+			break;
+		case 'V':
+			if (mode == MODE_TYPE) {
+				rlen += snprintf(buf+rlen, maxlen - rlen, "void");
+				while(array--)
+					rlen += snprintf(buf+rlen, maxlen - rlen, "[]");
+				array = 0;
+			} else
+				buf[rlen++] = *q;
+			break;
+		case '[':
+			if (mode != MODE_TYPE)
+				goto error;
+			array++;
+			break;
+		case '(':
+			if (mode != MODE_FUNC)
+				goto error;
+			buf[rlen++] = *q;
+			mode = MODE_TYPE;
+			break;
+		case ')':
+			if (mode != MODE_TYPE)
+				goto error;
+			buf[rlen++] = *q;
+			narg = 0;
+			break;
+		case ';':
+			if (mode != MODE_CLASS && mode != MODE_CTYPE)
+				goto error;
+			/* safe because at least one other char to process */
+			if (isalpha(*(q+1)))
+				rlen += snprintf(buf+rlen, maxlen - rlen, ".");
+			if (mode == MODE_CLASS)
+				mode = MODE_FUNC;
+			else if (mode == MODE_CTYPE)
+				mode = MODE_TYPE;
+			break;
+		case '/':
+			if (mode != MODE_CLASS && mode != MODE_CTYPE)
+				goto error;
+			rlen += snprintf(buf+rlen, maxlen - rlen, ".");
+			break;
+		default :
+			buf[rlen++] = *q;
+		}
+	}
+	buf[rlen] = '\0';
+	return buf;
+error:
+	return NULL;
+}
+
+/*
+ * Demangle Java function signature (openJDK, not GCJ)
+ * input:
+ * 	str: string to parse. String is not modified
+ *    flags: comobination of JAVA_DEMANGLE_* flags to modify demangling
+ * return:
+ *	if input can be demangled, then a newly allocated string is returned.
+ *	if input cannot be demangled, then NULL is returned
+ *
+ * Note: caller is responsible for freeing demangled string
+ */
+char *
+java_demangle_sym(const char *str, int flags)
+{
+	char *buf, *ptr;
+	char *p;
+	size_t len, l1 = 0;
+
+	if (!str)
+		return NULL;
+
+	/* find start of retunr type */
+	p = strrchr(str, ')');
+	if (!p)
+		return NULL;
+
+	/*
+	 * expansion factor estimated to 3x
+	 */
+	len = strlen(str) * 3 + 1;
+	buf = malloc(len);
+	if (!buf)
+		return NULL;
+
+	buf[0] = '\0';
+	if (!(flags & JAVA_DEMANGLE_NORET)) {
+		/*
+		 * get return type first
+		 */
+		ptr = __demangle_java_sym(p+1, NULL, buf, len, MODE_TYPE);
+		if (!ptr)
+			goto error;
+
+		/* add space between return type and function prototype */
+		l1 = strlen(buf);
+		buf[l1++] = ' ';
+	}
+
+	/* process function up to return type */
+	ptr = __demangle_java_sym(str, p + 1, buf + l1, len - l1, MODE_PREFIX);
+	if (!ptr)
+		goto error;
+
+	return buf;
+error:
+	free(buf);
+	return NULL;
+}
diff --git a/tools/perf/util/demangle-java.h b/tools/perf/util/demangle-java.h
new file mode 100644
index 0000000..a981c1f
--- /dev/null
+++ b/tools/perf/util/demangle-java.h
@@ -0,0 +1,10 @@
+#ifndef __PERF_DEMANGLE_JAVA
+#define __PERF_DEMANGLE_JAVA 1
+/*
+ * demangle function flags
+ */
+#define JAVA_DEMANGLE_NORET	0x1 /* do not process return type */
+
+char * java_demangle_sym(const char *str, int flags);
+
+#endif /* __PERF_DEMANGLE_JAVA */
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index b24f9d8..73b3e8f 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -6,6 +6,7 @@
 #include <inttypes.h>
 
 #include "symbol.h"
+#include "demangle-java.h"
 #include "machine.h"
 #include "vdso.h"
 #include <symbol/kallsyms.h>
@@ -1019,6 +1020,8 @@ int dso__load_sym(struct dso *dso, struct map *map,
 				demangle_flags = DMGL_PARAMS | DMGL_ANSI;
 
 			demangled = bfd_demangle(NULL, elf_name, demangle_flags);
+			if (demangled == NULL)
+				demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
 			if (demangled != NULL)
 				elf_name = demangled;
 		}
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index a690668..3bc779b 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -9,6 +9,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <inttypes.h>
+#include <bfd.h>
 #include "build-id.h"
 #include "util.h"
 #include "debug.h"
@@ -1257,6 +1258,7 @@ static int dso__load_perf_map(struct dso *dso, struct map *map,
 		u64 start, size;
 		struct symbol *sym;
 		int line_len, len;
+		char *name;
 
 		line_len = getline(&line, &n, file);
 		if (line_len < 0)
@@ -1279,7 +1281,9 @@ static int dso__load_perf_map(struct dso *dso, struct map *map,
 		if (len + 2 >= line_len)
 			continue;
 
-		sym = symbol__new(start, size, STB_GLOBAL, line + len);
+		name = line + len;
+
+		sym = symbol__new(start, size, STB_GLOBAL, name);
 
 		if (sym == NULL)
 			goto out_delete_line;
-- 
1.9.1

[PATCH v2 2/4] perf inject: add jitdump mmap injection support

[Stephane Eranian]

This patch adds a -j jitdump 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:
$ java -agentpath:libpjvmti.so java_class
$ perf inject -j ~/.debug/jit/java-jit-20140514.XXAb0e5C/jit-7640.dump \
              -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.

Signed-off-by: Stephane Eranian <eranian@google.com>
---
 tools/perf/Documentation/perf-inject.txt |  11 +
 tools/perf/Makefile.perf                 |   6 +-
 tools/perf/builtin-inject.c              | 205 ++++++++++++++
 tools/perf/util/genelf.c                 | 463 +++++++++++++++++++++++++++++++
 tools/perf/util/genelf.h                 |   6 +
 tools/perf/util/jit.h                    |  27 ++
 tools/perf/util/jitdump.c                | 233 ++++++++++++++++
 tools/perf/util/jitdump.h                |  92 ++++++
 8 files changed, 1042 insertions(+), 1 deletion(-)
 create mode 100644 tools/perf/util/genelf.c
 create mode 100644 tools/perf/util/genelf.h
 create mode 100644 tools/perf/util/jit.h
 create mode 100644 tools/perf/util/jitdump.c
 create mode 100644 tools/perf/util/jitdump.h

diff --git a/tools/perf/Documentation/perf-inject.txt b/tools/perf/Documentation/perf-inject.txt
index dc7442c..237f195 100644
--- a/tools/perf/Documentation/perf-inject.txt
+++ b/tools/perf/Documentation/perf-inject.txt
@@ -40,6 +40,17 @@ OPTIONS
 	Merge sched_stat and sched_switch for getting events where and how long
 	tasks slept. sched_switch contains a callchain where a task slept and
 	sched_stat contains a timeslice how long a task slept.
+-j::
+--jit::
+	Merge a jitdump file into the perf.data file by adding mmap records to
+	cover jitted code and emit ELF images for each jitted function. The ELF
+	images are saved in the same directory as the jidump. Use -E to suppress
+	ELF images generation.
+-E::
+--jit-disable-elf::
+	When used with -, it prevents creating the ELF images for each jitted
+	function. Only the jitted code mmap records are injected into the perf.data
+	file. Option as no effect when -j is not used.
 
 --kallsyms=<file>::
 	kallsyms pathname
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 53a44be..d405632 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -324,6 +324,7 @@ LIB_H += util/perf_regs.h
 LIB_H += util/unwind.h
 LIB_H += util/vdso.h
 LIB_H += util/tsc.h
+LIB_H += util/jitdump.h
 LIB_H += ui/helpline.h
 LIB_H += ui/progress.h
 LIB_H += ui/util.h
@@ -412,6 +413,8 @@ LIB_OBJS += $(OUTPUT)util/tsc.o
 LIB_OBJS += $(OUTPUT)util/cloexec.o
 LIB_OBJS += $(OUTPUT)util/thread-stack.o
 LIB_OBJS += $(OUTPUT)util/demangle-java.o
+LIB_OBJS += $(OUTPUT)util/jitdump.o
+LIB_OBJS += $(OUTPUT)util/genelf.o
 
 LIB_OBJS += $(OUTPUT)ui/setup.o
 LIB_OBJS += $(OUTPUT)ui/helpline.o
@@ -498,7 +501,8 @@ BUILTIN_OBJS += $(OUTPUT)builtin-inject.o
 BUILTIN_OBJS += $(OUTPUT)tests/builtin-test.o
 BUILTIN_OBJS += $(OUTPUT)builtin-mem.o
 
-PERFLIBS = $(LIB_FILE) $(LIBAPIKFS) $(LIBTRACEEVENT)
+PERFLIBS = $(LIB_FILE) $(LIBAPIKFS) $(LIBTRACEEVENT) -lcrypto
+
 
 # We choose to avoid "if .. else if .. else .. endif endif"
 # because maintaining the nesting to match is a pain.  If
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index a13641e..436203c 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -16,6 +16,8 @@
 #include "util/debug.h"
 #include "util/build-id.h"
 #include "util/data.h"
+#include "util/jit.h"
+#include "util/genelf.h"
 
 #include "util/parse-options.h"
 
@@ -30,6 +32,12 @@ struct perf_inject {
 	struct perf_data_file	output;
 	u64			bytes_written;
 	struct list_head	samples;
+
+	const char		*jit_filename;
+	FILE		 	*jit_file;
+	struct jit_buf_desc	jit_desc;
+	char			jit_dir[PATH_MAX];
+	bool		 	jit_disable_elf;
 };
 
 struct event_entry {
@@ -334,7 +342,170 @@ static int perf_evsel__check_stype(struct perf_evsel *evsel,
 			name, sample_msg);
 		return -EINVAL;
 	}
+	return 0;
+}
+
+static int jit_emit_elf(char *filename,
+			const char *sym,
+			unsigned long code,
+			int csize)
+{
+	int ret, fd;
+	unsigned long addr = (unsigned long)code;
+
+	fd = open(filename, O_CREAT|O_TRUNC|O_WRONLY, 0644);
+	if (fd == -1) {
+		pr_warning("cannot create jit ELF %s: %s\n", filename, strerror(errno));
+		return -1;
+	}
+
+        ret = jit_write_elf(fd, addr, sym, (const void *)code, csize);
+
+        close(fd);
+
+        if (ret)
+                unlink(filename);
+
+	return ret;
+}
+
+static int jit_repipe_code_load(struct perf_inject *inject, union jr_entry *jr)
+{
+	struct perf_sample sample;
+	union perf_event *event;
+	unsigned long code, addr;
+	size_t size;
+	const char *sym;
+	uint32_t count;
+	int ret, csize;
+	pid_t pid;
+	struct {
+		u32 pid, tid;
+		u64 time;
+	} *id;
+
+	pid   = jr->load.pid;
+	csize = jr->load.code_size;
+	addr  = jr->load.code_addr;
+	sym   = (void *)((unsigned long)jr + sizeof(jr->load));
+	code  = (unsigned long)jr + jr->load.p.total_size - csize;
+	count = jr->load.code_index;
+
+	/*
+	 * +16 to account for sample_id_all (hack)
+	 */
+	event = malloc(sizeof(*event) + 16);
+	if (!event)
+		return -1;
+
+	memset(event, 0, sizeof(*event));
+
+	size = snprintf(event->mmap.filename, PATH_MAX, "%s/jitted-%d-%u",
+		 inject->jit_dir,
+		 pid,
+		 count) + 1;
+	size = PERF_ALIGN(size, sizeof(u64));
+	if (!inject->jit_disable_elf) {
+		ret = jit_emit_elf(event->mmap.filename, sym, code, csize);
+		if (ret) {
+			free(event);
+			return -1;
+		}
+	}
+
+	event->mmap.header.type = PERF_RECORD_MMAP;
+	event->mmap.header.misc = PERF_RECORD_MISC_USER;
+	//event->mmap.header.size = sizeof(event->mmap) + 16;
+	event->mmap.header.size = (sizeof(event->mmap) -
+			(sizeof(event->mmap.filename) - size) + 16); //machine->id_hdr_size);
+	event->mmap.pgoff = 0;
+	event->mmap.start = addr;
+	event->mmap.len   = csize;
+	event->mmap.pid   = pid;
+	event->mmap.tid   = jr->load.tid;
+
+	id = (void *)((unsigned long)event + event->mmap.header.size - 16);
+	id->pid  = pid;
+	id->tid  = jr->load.tid;
+	id->time = jr->load.p.timestamp;
+
+	memset(&sample, 0, sizeof(sample));
+	sample.time = id->time;
+
+	return perf_event__repipe_synth(&inject->tool, event);
+}
+
+static int jit_repipe_code_move(struct perf_inject *inject, union jr_entry *jr)
+{
+	struct perf_sample sample;
+	union perf_event *event;
+	pid_t pid;
+	struct {
+		u32 pid, tid;
+		u64 time;
+	} *id;
+
+	pid      = jr->move.pid;
+
+	/*
+	 * +16 to account for sample_id_all (hack)
+	 */
+	event = malloc(sizeof(*event) + 16);
+	if (!event)
+		return -1;
+
+	memset(event, 0, sizeof(*event));
+
+	snprintf(event->mmap.filename, PATH_MAX, "%s/jitted-%d-%"PRIu64,
+	         inject->jit_dir,
+	         pid,
+		 jr->move.code_index);
+
+	event->mmap.header.type = PERF_RECORD_MMAP;
+	event->mmap.header.misc = PERF_RECORD_MISC_USER;
+	event->mmap.header.size = sizeof(event->mmap) + 16;
+	event->mmap.pgoff = 0;
+	event->mmap.start = jr->move.new_code_addr;
+	event->mmap.len   = jr->move.code_size;
+	event->mmap.pid   = pid;
+	event->mmap.tid   = jr->move.tid;
+
+	id = (void *)((unsigned long)event + sizeof(event->mmap));
+	id->pid  = pid;
+	id->tid  = jr->move.tid;
+	id->time = jr->move.p.timestamp;
+
+	memset(&sample, 0, sizeof(sample));
+	sample.time = id->time;
+
+	return perf_event__repipe_synth(&inject->tool, event);
+}
+
+static int perf_jit_inject(struct perf_inject *inject)
+{
+	union jr_entry *jr;
+
+	strncpy(inject->jit_dir, inject->jit_filename, PATH_MAX);
+	dirname(inject->jit_dir);
+
+	if (!strcmp(inject->jit_filename, inject->jit_dir)) {
+		inject->jit_dir[0] = '.';
+		inject->jit_dir[1] = '\0';
+	}
 
+	while ((jr = jit_get_next_entry(&inject->jit_desc))) {
+		switch(jr->prefix.id) {
+		case JIT_CODE_LOAD:
+			jit_repipe_code_load(inject, jr);
+			break;
+		case JIT_CODE_MOVE:
+			pr_warning("CODE_MOVE\n");
+			jit_repipe_code_move(inject, jr);
+			break;
+		default:
+			continue;
+		}
+	}
 	return 0;
 }
 
@@ -381,6 +552,9 @@ static int __cmd_inject(struct perf_inject *inject)
 
 	ret = perf_session__process_events(session, &inject->tool);
 
+	if (ret == 0 && inject->jit_filename)
+		ret = perf_jit_inject(inject);
+
 	if (!file_out->is_pipe) {
 		if (inject->build_ids)
 			perf_header__set_feat(&session->header,
@@ -418,6 +592,8 @@ int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
 			.path = "-",
 			.mode = PERF_DATA_MODE_WRITE,
 		},
+		.jit_disable_elf = false,
+
 	};
 	struct perf_data_file file = {
 		.mode = PERF_DATA_MODE_READ,
@@ -434,6 +610,10 @@ int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
 		OPT_BOOLEAN('s', "sched-stat", &inject.sched_stat,
 			    "Merge sched-stat and sched-switch for getting events "
 			    "where and how long tasks slept"),
+		OPT_STRING('j', "jit", &inject.jit_filename, "merge jitdump file",
+			   "input file name"),
+		OPT_BOOLEAN('E', "jit-disable-elf", &inject.jit_disable_elf,
+			    "Do not emit ELF images from jitdump file"),
 		OPT_INCR('v', "verbose", &verbose,
 			 "be more verbose (show build ids, etc)"),
 		OPT_STRING(0, "kallsyms", &symbol_conf.kallsyms_name, "file",
@@ -463,6 +643,28 @@ int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (inject.session == NULL)
 		return -1;
 
+	if (inject.build_ids) {
+		/*
+		 * 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 at the same time for now.
+		 */
+		inject.tool.ordered_events = true;
+		inject.tool.ordering_requires_timestamps = true;
+	}
+
+	if (inject.jit_filename) {
+		inject.tool.ordered_events = true;
+		inject.tool.ordering_requires_timestamps = true;
+		ret = jit_open_dump(inject.jit_filename, &inject.jit_desc);
+		if (ret) {
+			fprintf(stderr, "cannot open jitdump file %s\n", inject.jit_filename);
+			return -1;
+		}
+	}
+
+
 	if (symbol__init(&inject.session->header.env) < 0)
 		return -1;
 
@@ -470,5 +672,8 @@ int cmd_inject(int argc, const char **argv, const char *prefix __maybe_unused)
 
 	perf_session__delete(inject.session);
 
+	if (inject.jit_filename)
+		jit_close_dump(&inject.jit_desc);
+
 	return ret;
 }
diff --git a/tools/perf/util/genelf.c b/tools/perf/util/genelf.c
new file mode 100644
index 0000000..a6f9e43
--- /dev/null
+++ b/tools/perf/util/genelf.c
@@ -0,0 +1,463 @@
+/*
+ * genelf.c
+ * Copyright (C) 2014, Google, Inc
+ *
+ * Contributed by:
+ * 	Stephane Eranian <eranian@gmail.com>
+ *
+ * Released under the GPL v2. (and only v2, not any later version)
+ */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <getopt.h>
+#include <stddef.h>
+#include <libelf.h>
+#include <string.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <err.h>
+
+#include "perf.h"
+#include "genelf.h"
+
+#define JVMTI
+#define BUILD_ID_MD5
+#undef BUILD_ID_SHA	/* does not seem to work well when linked with Java */
+#undef  BUILD_ID_URANDOM	/* different uuid for each run */
+
+#ifdef BUILD_ID_SHA
+#include <openssl/sha.h>
+#endif
+
+#ifdef BUILD_ID_MD5
+#include <openssl/md5.h>
+#endif
+
+#if   defined(__arm__)
+#define GEN_ELF_ARCH	EM_ARM
+#define GEN_ELF_ENDIAN	ELFDATA2LSB
+#define GEN_ELF_CLASS	ELFCLASS32
+#elif defined(__x86_64__)
+#define GEN_ELF_ARCH	EM_X86_64
+#define GEN_ELF_ENDIAN	ELFDATA2LSB
+#define GEN_ELF_CLASS	ELFCLASS64
+#elif defined(__i386__)
+#define GEN_ELF_ARCH	EM_386
+#define GEN_ELF_ENDIAN	ELFDATA2LSB
+#define GEN_ELF_CLASS	ELFCLASS32
+#elif defined(__ppcle__)
+#define GEN_ELF_ARCH	EM_PPC
+#define GEN_ELF_ENDIAN	ELFDATA2LSB
+#define GEN_ELF_CLASS	ELFCLASS64
+#elif defined(__powerpc__)
+#define GEN_ELF_ARCH	EM_PPC64
+#define GEN_ELF_ENDIAN	ELFDATA2MSB
+#define GEN_ELF_CLASS	ELFCLASS64
+#elif defined(__powerpcle__)
+#define GEN_ELF_ARCH	EM_PPC64
+#define GEN_ELF_ENDIAN	ELFDATA2LSB
+#define GEN_ELF_CLASS	ELFCLASS64
+#else
+#error "unsupported architecture"
+#endif
+
+#if GEN_ELF_CLASS == ELFCLASS64
+#define elf_newehdr	elf64_newehdr
+#define elf_getshdr	elf64_getshdr
+#define Elf_Ehdr	Elf64_Ehdr
+#define Elf_Shdr	Elf64_Shdr
+#define Elf_Sym		Elf64_Sym
+#define ELF_ST_TYPE(a)	ELF64_ST_TYPE(a)
+#define ELF_ST_BIND(a)	ELF64_ST_BIND(a)
+#define ELF_ST_VIS(a)	ELF64_ST_VISIBILITY(a)
+#else
+#define elf_newehdr	elf32_newehdr
+#define elf_getshdr	elf32_getshdr
+#define Elf_Ehdr	Elf32_Ehdr
+#define Elf_Shdr	Elf32_Shdr
+#define Elf_Sym		Elf32_Sym
+#define ELF_ST_TYPE(a)	ELF32_ST_TYPE(a)
+#define ELF_ST_BIND(a)	ELF32_ST_BIND(a)
+#define ELF_ST_VIS(a)	ELF32_ST_VISIBILITY(a)
+#endif
+
+typedef struct {
+  unsigned int namesz;  /* Size of entry's owner string */
+  unsigned int descsz;  /* Size of the note descriptor */
+  unsigned int type;    /* Interpretation of the descriptor */
+  char         name[0]; /* Start of the name+desc data */
+} Elf_Note;
+
+struct options {
+	char *output;
+	int fd;
+};
+
+static char shd_string_table[] = {
+	0,
+	'.', 't', 'e', 'x', 't', 0,			/*  1 */
+	'.', 's', 'h', 's', 't', 'r', 't', 'a', 'b', 0, /*  7 */
+	'.', 's', 'y', 'm', 't', 'a', 'b', 0,		/* 17 */
+	'.', 's', 't', 'r', 't', 'a', 'b', 0,		/* 25 */
+	'.', 'n', 'o', 't', 'e', '.', 'g', 'n', 'u', '.', 'b', 'u', 'i', 'l', 'd', '-', 'i', 'd', 0, /* 33 */
+};
+
+
+static struct buildid_note {
+	Elf_Note desc;		/* descsz: size of build-id, must be multiple of 4 */
+	char	 name[4];	/* GNU\0 */
+	char	 build_id[20];
+} bnote;
+
+static Elf_Sym symtab[]={
+	/* symbol 0 MUST be the undefined symbol */
+	{ .st_name  = 0, /* index in sym_string table */
+	  .st_info  = ELF_ST_TYPE(STT_NOTYPE),
+	  .st_shndx = 0, /* for now */
+	  .st_value = 0x0,
+	  .st_other = ELF_ST_VIS(STV_DEFAULT),
+	  .st_size  = 0,
+	},
+	{ .st_name  = 1, /* index in sym_string table */
+	  .st_info  = ELF_ST_BIND(STB_LOCAL) | ELF_ST_TYPE(STT_FUNC),
+	  .st_shndx = 1,
+	  .st_value = 0, /* for now */
+	  .st_other = ELF_ST_VIS(STV_DEFAULT),
+	  .st_size  = 0, /* for now */
+	}
+};
+
+#ifdef BUILD_ID_URANDOM
+static void
+gen_build_id(struct buildid_note *note, unsigned long load_addr, const void *code, size_t csize)
+{
+	int fd;
+
+	fd = open("/dev/urandom", O_RDONLY);
+	if (fd == -1)
+		err(1, "cannot access /dev/urandom for builid");
+	read(fd, note->build_id, sizeof(note->build_id));
+	close(fd);
+}
+#endif
+
+#ifdef BUILD_ID_SHA
+static void
+gen_build_id(struct buildid_note *note,
+	     unsigned long load_addr __maybe_unused,
+	     const void *code,
+	     size_t csize)
+{
+        if (sizeof(note->build_id) < SHA_DIGEST_LENGTH)
+                errx(1, "build_id too small for SHA1");
+
+	SHA1(code, csize, (unsigned char *)note->build_id);
+}
+#endif
+
+#ifdef BUILD_ID_MD5
+static void
+gen_build_id(struct buildid_note *note, unsigned long load_addr, const void *code, size_t csize)
+{
+        MD5_CTX context;
+
+        if (sizeof(note->build_id) < 16)
+                errx(1, "build_id too small for MD5");
+
+        MD5_Init(&context);
+        MD5_Update(&context, &load_addr, sizeof(load_addr));
+        MD5_Update(&context, code, csize);
+        MD5_Final((unsigned char *)note->build_id, &context);
+}
+#endif
+
+/*
+ * fd: file descriptor open for writing for the output file
+ * load_addr: code load address (could be zero, just used for buildid)
+ * sym: function name (for native code - used as the symbol)
+ * code: the native code
+ * csize: the code size in bytes
+ */
+int
+jit_write_elf(int fd, unsigned long load_addr, const char *sym, const void *code, int csize)
+{
+	Elf *e;
+	Elf_Data *d;
+	Elf_Scn *scn;
+	Elf_Ehdr *ehdr;
+	Elf_Shdr *shdr;
+	char *strsym = NULL;
+	int symlen;
+	int retval = -1;
+
+	if (elf_version(EV_CURRENT) == EV_NONE) {
+		warnx("ELF initialization failed");
+		return -1;
+	}
+
+	e = elf_begin(fd, ELF_C_WRITE, NULL);
+	if (!e) {
+		warnx("elf_begin failed");
+		goto error;
+	}
+
+	/*
+	 * setup ELF header
+	 */
+	ehdr = elf_newehdr(e);
+	if (!ehdr) {
+		warnx("cannot get ehdr");
+		goto error;
+	}
+
+	ehdr->e_ident[EI_DATA] = GEN_ELF_ENDIAN;
+	ehdr->e_ident[EI_CLASS] = GEN_ELF_CLASS;
+	ehdr->e_machine = GEN_ELF_ARCH;
+	ehdr->e_type = ET_DYN;
+	ehdr->e_entry = 0x0;
+	ehdr->e_version = EV_CURRENT;
+	ehdr->e_shstrndx= 2; /* shdr index for section name */
+
+	/*
+	 * setup text section
+	 */
+	scn = elf_newscn(e);
+	if (!scn) {
+		warnx("cannot create section");
+		goto error;
+	}
+
+	d = elf_newdata(scn);
+	if (!d) {
+		warnx("cannot get new data");
+		goto error;
+	}
+
+	d->d_align = 16;
+	d->d_off = 0LL;
+	d->d_buf = (void *)code;
+	d->d_type = ELF_T_BYTE;
+	d->d_size = csize;
+	d->d_version = EV_CURRENT;
+
+	shdr = elf_getshdr(scn);
+	if (!shdr) {
+		warnx("cannot get section header");
+		goto error;
+	}
+
+	shdr->sh_name = 1;
+	shdr->sh_type = SHT_PROGBITS;
+	shdr->sh_addr = 0; /* must be zero or == sh_offset -> dynamic object */
+	shdr->sh_flags = SHF_EXECINSTR | SHF_ALLOC;
+	shdr->sh_entsize = 0;
+
+	/*
+	 * setup section headers string table
+	 */
+	scn = elf_newscn(e);
+	if (!scn) {
+		warnx("cannot create section");
+		goto error;
+	}
+
+	d = elf_newdata(scn);
+	if (!d) {
+		warnx("cannot get new data");
+		goto error;
+	}
+
+	d->d_align = 1;
+	d->d_off = 0LL;
+	d->d_buf = shd_string_table;
+	d->d_type = ELF_T_BYTE;
+	d->d_size = sizeof(shd_string_table);
+	d->d_version = EV_CURRENT;
+
+	shdr = elf_getshdr(scn);
+	if (!shdr) {
+		warnx("cannot get section header");
+		goto error;
+	}
+
+	shdr->sh_name = 7; /* offset of '.shstrtab' in shd_string_table */
+	shdr->sh_type = SHT_STRTAB;
+	shdr->sh_flags = 0;
+	shdr->sh_entsize = 0;
+
+	/*
+	 * setup symtab section
+	 */
+	symtab[1].st_size  = csize;
+
+	scn = elf_newscn(e);
+	if (!scn) {
+		warnx("cannot create section");
+		goto error;
+	}
+
+	d = elf_newdata(scn);
+	if (!d) {
+		warnx("cannot get new data");
+		goto error;
+	}
+
+	d->d_align = 8;
+	d->d_off = 0LL;
+	d->d_buf = symtab;
+	d->d_type = ELF_T_SYM;
+	d->d_size = sizeof(symtab);
+	d->d_version = EV_CURRENT;
+
+	shdr = elf_getshdr(scn);
+	if (!shdr) {
+		warnx("cannot get section header");
+		goto error;
+	}
+
+	shdr->sh_name = 17; /* offset of '.symtab' in shd_string_table */
+	shdr->sh_type = SHT_SYMTAB;
+	shdr->sh_flags = 0;
+	shdr->sh_entsize = sizeof(Elf_Sym);
+	shdr->sh_link = 4; /* index of .strtab section */
+
+	/*
+	 * setup symbols string table
+	 * 2 = 1 for 0 in 1st entry, 1 for the 0 at end of symbol for 2nd entry
+	 */
+	symlen = 2 + strlen(sym);
+	strsym = calloc(1, symlen);
+	if (!strsym) {
+		warnx("cannot allocate strsym");
+		goto error;
+	}
+	strcpy(strsym + 1, sym);
+
+	scn = elf_newscn(e);
+	if (!scn) {
+		warnx("cannot create section");
+		goto error;
+	}
+
+	d = elf_newdata(scn);
+	if (!d) {
+		warnx("cannot get new data");
+		goto error;
+	}
+
+	d->d_align = 1;
+	d->d_off = 0LL;
+	d->d_buf = strsym;
+	d->d_type = ELF_T_BYTE;
+	d->d_size = symlen;
+	d->d_version = EV_CURRENT;
+
+	shdr = elf_getshdr(scn);
+	if (!shdr) {
+		warnx("cannot get section header");
+		goto error;
+	}
+
+	shdr->sh_name = 25; /* offset in shd_string_table */
+	shdr->sh_type = SHT_STRTAB;
+	shdr->sh_flags = 0;
+	shdr->sh_entsize = 0;
+
+	/*
+	 * setup build-id section
+	 */
+	scn = elf_newscn(e);
+	if (!scn) {
+		warnx("cannot create section");
+		goto error;
+	}
+
+	d = elf_newdata(scn);
+	if (!d) {
+		warnx("cannot get new data");
+		goto error;
+	}
+	
+	/*
+	 * build-id generation
+	 */
+	gen_build_id(&bnote, load_addr, code, csize);
+	bnote.desc.namesz = sizeof(bnote.name); /* must include 0 termination */
+	bnote.desc.descsz = sizeof(bnote.build_id);
+	bnote.desc.type   = NT_GNU_BUILD_ID;
+	strcpy(bnote.name, "GNU");
+
+	d->d_align = 4;
+	d->d_off = 0LL;
+	d->d_buf = &bnote;
+	d->d_type = ELF_T_BYTE;
+	d->d_size = sizeof(bnote);
+	d->d_version = EV_CURRENT;
+
+	shdr = elf_getshdr(scn);
+	if (!shdr) {
+		warnx("cannot get section header");
+		goto error;
+	}
+
+	shdr->sh_name = 33; /* offset in shd_string_table */
+	shdr->sh_type = SHT_NOTE;
+	shdr->sh_addr = 0x0;
+	shdr->sh_flags = SHF_ALLOC;
+	shdr->sh_size = sizeof(bnote);
+	shdr->sh_entsize = 0;
+
+	if (elf_update(e, ELF_C_WRITE) < 0) {
+		warnx("elf_update 4 failed");
+		goto error;
+	}
+	(void)elf_end(e);
+
+	retval = 0;
+error:
+	free(strsym);
+
+	return retval;
+}
+
+#ifndef JVMTI
+
+static unsigned char x86_code[] = {
+    0xBB, 0x2A, 0x00, 0x00, 0x00, /* movl $42, %ebx */
+    0xB8, 0x01, 0x00, 0x00, 0x00, /* movl $1, %eax */
+    0xCD, 0x80            /* int $0x80 */
+};
+
+static struct options options;
+
+int main(int argc, char **argv)
+{
+	int c, fd, ret;
+
+	while ((c = getopt(argc, argv, "o:h")) != -1) {
+		switch (c) {
+		case 'o':
+			options.output = optarg;
+			break;
+		case 'h':
+			printf("Usage: genelf -o output_file [-h]\n");
+			return 0;
+		default:
+			errx(1, "unknown option");
+		}
+	}
+
+	fd = open(options.output, O_CREAT|O_TRUNC|O_RDWR, 0666);
+	if (fd == -1)
+		err(1, "cannot create file %s", options.output);
+
+	ret = jit_write_elf(fd, "main", x86_code, sizeof(x86_code));
+	close(fd);
+
+	if (ret != 0)
+		unlink(options.output);
+
+	return ret;
+}
+#endif
diff --git a/tools/perf/util/genelf.h b/tools/perf/util/genelf.h
new file mode 100644
index 0000000..11307a2
--- /dev/null
+++ b/tools/perf/util/genelf.h
@@ -0,0 +1,6 @@
+#ifndef __GENELF_H__
+#define __GENELF_H__
+
+extern int jit_write_elf(int fd, unsigned long code_addr, const char *sym, const void *code, int csize);
+
+#endif
diff --git a/tools/perf/util/jit.h b/tools/perf/util/jit.h
new file mode 100644
index 0000000..e7a54cb
--- /dev/null
+++ b/tools/perf/util/jit.h
@@ -0,0 +1,27 @@
+#ifndef __JIT_H__
+#define __JIT_H__
+#include <sys/time.h>
+#include <stdint.h>
+
+#include "jitdump.h"
+
+struct jit_buf_desc {
+	union jr_entry  *entry;
+	void            *buf;
+	size_t          bufsize;
+	FILE            *in;
+	int             needs_bswap; /* handles cross-endianess */
+	uint32_t        code_load_count;
+	struct rb_root  code_root;
+};
+ 
+extern int jit_open_dump(const char *name, struct jit_buf_desc *jd);
+extern void jit_close_dump(struct jit_buf_desc *jd);
+extern union jr_entry *jit_get_next_entry(struct jit_buf_desc *jd);
+
+/*
+ * use type = -1 to match any record type
+ */
+extern union jr_entry *jit_get_next_entry_type(struct jit_buf_desc *jd, int type);
+
+#endif /* __JIT_H__ */
diff --git a/tools/perf/util/jitdump.c b/tools/perf/util/jitdump.c
new file mode 100644
index 0000000..28a9429
--- /dev/null
+++ b/tools/perf/util/jitdump.c
@@ -0,0 +1,233 @@
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <byteswap.h>
+
+#include "util.h"
+#include "debug.h"
+#include "symbol.h"
+#include "strlist.h"
+#include <elf.h>
+
+#include "jit.h"
+
+struct debug_line_info {
+	unsigned long vma;
+	unsigned int lineno;
+	/* The filename format is unspecified, absolute path, relative etc. */
+	char const filename[0];
+};
+
+#define hmax(a, b) ((a) > (b) ? (a) : (b))
+
+void
+jit_close_dump(struct jit_buf_desc *jd)
+{
+	if (!(jd && jd->in))
+		return;
+	fclose(jd->in);
+	jd->in = NULL;
+}
+
+int
+jit_open_dump(const char *name, struct jit_buf_desc *jd)
+{
+	struct jitheader header;
+	struct jr_prefix *prefix;
+	ssize_t bs, bsz = 0;
+	void *n, *buf = NULL;
+	int ret, retval = -1;
+
+	if (!jd || jd->in)
+		return -1;
+
+	memset(jd, 0, sizeof(*jd));
+
+	jd->in = fopen(name, "r");
+	if (!jd->in)
+		return -1;
+
+	bsz = hmax(sizeof(header), sizeof(*prefix));
+
+	buf = malloc(bsz);
+	if (!buf)
+		goto error;
+
+	ret = fread(buf, sizeof(header), 1, jd->in);
+	if (ret != 1)
+		goto error;
+
+	memcpy(&header, buf, sizeof(header));
+
+	if (header.magic != JITHEADER_MAGIC) {
+		if (header.magic != JITHEADER_MAGIC_SW)
+			goto error;
+		jd->needs_bswap = 1;
+	}
+
+	if (jd->needs_bswap) {
+		header.version    = bswap_32(header.version);
+		header.total_size = bswap_32(header.total_size);
+		header.pid	  = bswap_32(header.pid);
+		header.elf_mach   = bswap_32(header.elf_mach);
+		header.timestamp  = bswap_32(header.timestamp);
+	}
+
+	pr_debug("version=%u\nsize=%u(%zu)\nts=0x%llx\npid=%d\nelf_mach=%d\n",
+		header.version,
+		header.total_size,
+		header.total_size - sizeof(header),
+		(unsigned long long)header.timestamp,
+		header.pid,
+		header.elf_mach);
+
+	bs = header.total_size - sizeof(header);
+
+	if (bs > bsz) {
+		n = realloc(buf, bs);
+		if (!n)
+			goto error;
+		bsz = bs;
+		buf = n;
+		/* read extra we do not know about */
+		ret = fread(buf, bs - bsz, 1, jd->in);
+		if (ret != 1)
+			goto error;
+	}
+	retval = 0;
+error:
+	return retval;
+}
+
+union jr_entry *
+jit_get_next_entry(struct jit_buf_desc *jd)
+{
+	struct jr_prefix *prefix;
+	union jr_entry *jr;
+	void *addr;
+	size_t bs, size;
+	int id, ret;
+
+	if (!(jd && jd->in))
+		return NULL;
+
+	if (jd->buf == NULL) {
+		size_t sz = getpagesize();
+		if (sz < sizeof(*prefix))
+			sz = sizeof(*prefix);
+
+		jd->buf = malloc(sz);
+		if (jd->buf == NULL)
+			return NULL;
+
+		jd->bufsize = sz;
+	}
+
+	prefix = jd->buf;
+
+	ret = fread(prefix, sizeof(*prefix), 1, jd->in);
+	if (ret  != 1)
+		return NULL;
+
+	if (jd->needs_bswap) {
+		prefix->id   	   = bswap_32(prefix->id);
+		prefix->total_size = bswap_32(prefix->total_size);
+		prefix->timestamp  = bswap_64(prefix->timestamp);
+	}
+	id   = prefix->id;
+	size = prefix->total_size;
+
+	bs = (size_t)size;
+	if (bs < sizeof(*prefix))
+		return NULL;
+
+	if (id >= JIT_CODE_MAX) {
+		pr_warning("next_entry: unknown prefix %d, skipping\n", id);
+		return NULL;
+	}
+	if (bs > jd->bufsize) {
+		void *n;
+		n = realloc(jd->buf, bs);
+		if (!n)
+			return NULL;
+		jd->buf = n;
+		jd->bufsize = bs;
+	}
+
+	addr = ((void *)jd->buf) + sizeof(*prefix);
+
+	ret = fread(addr, bs - sizeof(*prefix), 1, jd->in);
+	if (ret != 1)
+		return NULL;
+
+	jr = (union jr_entry *)jd->buf;
+
+	switch(id) {
+	case JIT_CODE_DEBUG_INFO:
+	case JIT_CODE_CLOSE:
+		break;
+	case JIT_CODE_LOAD:
+		if (jd->needs_bswap) {
+			jr->load.pid       = bswap_32(jr->load.pid);
+			jr->load.tid       = bswap_32(jr->load.tid);
+			jr->load.vma       = bswap_64(jr->load.vma);
+			jr->load.code_addr = bswap_64(jr->load.code_addr);
+			jr->load.code_size = bswap_64(jr->load.code_size);
+			jr->load.code_index= bswap_64(jr->load.code_index);
+		}
+		jd->code_load_count++;
+		break;
+	case JIT_CODE_MOVE:
+		if (jd->needs_bswap) {
+			jr->move.pid           = bswap_32(jr->move.pid);
+			jr->move.tid           = bswap_32(jr->move.tid);
+			jr->move.vma           = bswap_64(jr->move.vma);
+			jr->move.old_code_addr = bswap_64(jr->move.old_code_addr);
+			jr->move.new_code_addr = bswap_64(jr->move.new_code_addr);
+			jr->move.code_size     = bswap_64(jr->move.code_size);
+			jr->move.code_index    = bswap_64(jr->move.code_index);
+		}
+		break;
+	case JIT_CODE_MAX:
+	default:
+		return NULL;
+	}
+	return jr;
+}
+
+union jr_entry *
+jit_get_next_entry_type(struct jit_buf_desc *jd, int type)
+{
+	union jr_entry *jr;
+
+	while ((jr = jit_get_next_entry(jd))) {
+		if (type == -1 || (uint32_t)type == jr->prefix.id)
+			goto found;
+	}
+	return NULL;
+found:
+	switch(jr->prefix.id) {
+	case JIT_CODE_DEBUG_INFO:
+	case JIT_CODE_CLOSE:
+		break;
+	case JIT_CODE_LOAD:
+		if (jd->needs_bswap) {
+			jr->load.pid       = bswap_32(jr->load.pid);
+			jr->load.tid       = bswap_32(jr->load.tid);
+			jr->load.vma       = bswap_64(jr->load.vma);
+			jr->load.code_addr = bswap_64(jr->load.code_addr);
+			jr->load.code_size = bswap_32(jr->load.code_size);
+			jr->load.code_index= bswap_64(jr->load.code_index);
+		}
+		jd->code_load_count++;
+		break;
+	case JIT_CODE_MAX:
+	default:
+		return NULL;
+	}
+	return jr;
+}
diff --git a/tools/perf/util/jitdump.h b/tools/perf/util/jitdump.h
new file mode 100644
index 0000000..120bdcf
--- /dev/null
+++ b/tools/perf/util/jitdump.h
@@ -0,0 +1,92 @@
+/*
+ * jitdump.h: jitted code info encapsulation file format
+ *
+ * Adapted from OProfile GPLv2 support jidump.h:
+ * Copyright 2007 OProfile authors
+ * Jens Wilke
+ * Daniel Hansel
+ * Copyright IBM Corporation 2007
+ */
+#ifndef JITDUMP_H
+#define JITDUMP_H
+
+#include <sys/time.h>
+#include <time.h>
+#include <stdint.h>
+
+/* JiTD */
+#define JITHEADER_MAGIC		0x4A695444
+#define JITHEADER_MAGIC_SW	0x4454694A
+
+#define PADDING_8ALIGNED(x) ((((x) + 7) & 7) ^ 7)
+
+#define JITHEADER_VERSION 1
+
+struct jitheader {
+	uint32_t magic;		/* characters "jItD" */
+	uint32_t version;	/* header version */
+	uint32_t total_size;	/* total size of header */
+	uint32_t elf_mach;	/* elf mach target */
+	uint32_t pad1;		/* reserved */
+	uint32_t pid;		/* JIT process id */
+	uint64_t timestamp;	/* timestamp */
+};
+
+enum jit_record_type {
+	JIT_CODE_LOAD		= 0,
+        JIT_CODE_MOVE           = 1,
+	JIT_CODE_DEBUG_INFO	= 2,
+	JIT_CODE_CLOSE		= 3,
+
+	JIT_CODE_MAX,
+};
+
+/* record prefix (mandatory in each record) */
+struct jr_prefix {
+	uint32_t id;
+	uint32_t total_size;
+	uint64_t timestamp;
+};
+
+struct jr_code_load {
+	struct jr_prefix p;
+
+	uint32_t pid;
+	uint32_t tid;
+	uint64_t vma;
+	uint64_t code_addr;
+	uint64_t code_size;
+	uint64_t code_index;
+};
+
+struct jr_code_close {
+	struct jr_prefix p;
+};
+
+struct jr_code_move {
+	struct jr_prefix p;
+
+	uint32_t pid;
+	uint32_t tid;
+	uint64_t vma;
+	uint64_t old_code_addr;
+	uint64_t new_code_addr;
+	uint64_t code_size;
+	uint64_t code_index;
+};
+
+struct jr_code_debug_info {
+	struct jr_prefix p;
+
+	uint64_t code_addr;
+	uint64_t nr_entry;
+};
+
+union jr_entry {
+        struct jr_code_debug_info info;
+        struct jr_code_close close;
+        struct jr_code_load load;
+        struct jr_code_move move;
+        struct jr_prefix prefix;
+};
+#endif /* !JITDUMP_H */
-- 
1.9.1

[PATCH v2 3/4] perf tools: add JVMTI agent library

[Stephane 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 .......

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 next step is to inject the jitdump information into the
perf.data file:
$ perf inject -j $HOME/.debug/java/jit/java-jit-XXXX/jit-ZZZ.dump \
              -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 David Ahern/Pawell Moll
PERF_CLOCK posix clock kernel module. The source code is available
at:
  https://github.com/dsahern/linux/blob/perf-full-monty/README.ahern

The patch is repackaged as a kernel module for convenience in the
patch series.

The PERF_CLOCK module simplifies the user level operation. No
file descriptor, no chmod 644 of the driver file.

Signed-off-by: Stephane Eranian <eranian@google.com>
---
 tools/perf/jvmti/Makefile      |  70 +++++++++
 tools/perf/jvmti/jvmti_agent.c | 320 +++++++++++++++++++++++++++++++++++++++++
 tools/perf/jvmti/jvmti_agent.h |  23 +++
 tools/perf/jvmti/libjvmti.c    | 149 +++++++++++++++++++
 4 files changed, 562 insertions(+)
 create mode 100644 tools/perf/jvmti/Makefile
 create mode 100644 tools/perf/jvmti/jvmti_agent.c
 create mode 100644 tools/perf/jvmti/jvmti_agent.h
 create mode 100644 tools/perf/jvmti/libjvmti.c

diff --git a/tools/perf/jvmti/Makefile b/tools/perf/jvmti/Makefile
new file mode 100644
index 0000000..22efd13
--- /dev/null
+++ b/tools/perf/jvmti/Makefile
@@ -0,0 +1,70 @@
+ARCH=$(shell uname -m)
+
+ifeq ($(ARCH), x86_64)
+JARCH=amd64
+endif
+ifeq ($(ARCH), armv7l)
+JARCH=armhf
+endif
+ifeq ($(ARCH), armv6l)
+JARCH=armhf
+endif
+ifeq ($(ARCH), ppc64)
+JARCH=powerpc
+endif
+ifeq ($(ARCH), ppc64le)
+JARCH=powerpc
+endif
+
+DESTDIR=/usr/local
+
+VERSION=1
+REVISION=0
+AGE=0
+
+LN=ln -sf
+RM=rm
+
+SLIBJVMTI=libjvmti.so.$(VERSION).$(REVISION).$(AGE)
+VLIBJVMTI=libjvmti.so.$(VERSION)
+SLDFLAGS=-shared -Wl,-soname -Wl,$(VLIBJVMTI)
+SOLIBEXT=so
+
+JDIR=$(shell /usr/sbin/update-java-alternatives -l | head -1 | cut -d ' ' -f 3)
+# -lrt required in 32-bit mode for clock_gettime()
+LIBS=-lelf -lrt
+INCDIR=-I $(JDIR)/include -I $(JDIR)/include/linux
+
+TARGETS=$(SLIBJVMTI)
+
+SRCS=libjvmti.c jvmti_agent.c
+OBJS=$(SRCS:.c=.o)
+SOBJS=$(OBJS:.o=.lo)
+OPT=-O2 -g -Werror -Wall
+
+CFLAGS=$(INCDIR) $(OPT)
+
+all: $(TARGETS)
+
+.c.o:
+	$(CC) $(CFLAGS) -c $*.c
+.c.lo:
+	$(CC) -fPIC -DPIC $(CFLAGS) -c $*.c -o $*.lo
+
+$(OBJS) $(SOBJS): Makefile jvmti_agent.h ../util/jitdump.h
+
+$(SLIBJVMTI):  $(SOBJS)
+	$(CC) $(CFLAGS) $(SLDFLAGS)  -o $@ $(SOBJS) $(LIBS)
+	$(LN) $@ libjvmti.$(SOLIBEXT)
+
+clean:
+	$(RM) -f *.o *.so.* *.so *.lo
+
+install:
+	-mkdir -p $(DESTDIR)/lib
+	install -m 755 $(SLIBJVMTI) $(DESTDIR)/lib/
+	(cd $(DESTDIR)/lib; $(LN) $(SLIBJVMTI) $(VLIBJVMTI))
+	(cd $(DESTDIR)/lib; $(LN) $(SLIBJVMTI) libjvmti.$(SOLIBEXT))
+	ldconfig
+
+.SUFFIXES: .c .S .o .lo
diff --git a/tools/perf/jvmti/jvmti_agent.c b/tools/perf/jvmti/jvmti_agent.c
new file mode 100644
index 0000000..ac85452
--- /dev/null
+++ b/tools/perf/jvmti/jvmti_agent.c
@@ -0,0 +1,320 @@
+/*
+ * jvmti_agent.c: JVMTI agent interface
+ *
+ * Adapted from the Oprofile code in opagent.c:
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Copyright 2007 OProfile authors
+ * Jens Wilke
+ * Daniel Hansel
+ * Copyright IBM Corporation 2007
+ */
+#include <sys/types.h>
+#include <sys/stat.h> /* for mkdir() */
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <time.h>
+#include <syscall.h> /* for gettid() */
+#include <err.h>
+
+#include "jvmti_agent.h"
+#include "../util/jitdump.h"
+
+#define JIT_LANG "java"
+
+static char jit_path[PATH_MAX];
+
+/*
+ * padding buffer
+ */
+static const char pad_bytes[7];
+
+static inline pid_t gettid(void)
+{
+	return (pid_t)syscall(__NR_gettid);
+}
+
+static int get_e_machine(struct jitheader *hdr)
+{
+	ssize_t sret;
+	char id[16];
+	int fd, ret = -1;
+	int m = -1;
+	struct {
+		uint16_t e_type;
+		uint16_t e_machine;
+	} info;
+
+	fd = open("/proc/self/exe", O_RDONLY);
+	if (fd == -1)
+		return -1;
+
+	sret = read(fd, id, sizeof(id));
+	if (sret != sizeof(id))
+		goto error;
+
+	/* check ELF signature */
+	if (id[0] != 0x7f || id[1] != 'E' || id[2] != 'L' || id[3] != 'F')
+		goto error;
+
+	sret = read(fd, &info, sizeof(info));
+	if (sret != sizeof(info))
+		goto error;
+
+	m = info.e_machine;
+	if (m < 0)
+		m = 0; /* ELF EM_NONE */
+
+	hdr->elf_mach = m;
+	ret = 0;
+error:
+	close(fd);
+	return ret;
+}
+
+#define NSEC_PER_SEC	1000000000
+#ifndef PERF_LOCK
+#define PERF_CLOCK 12
+#endif
+static int
+perf_open_timestamp(void)
+{
+	struct timespec ts;
+	int ret;
+	/*
+	 * check if PERF_LOCK available
+	 */
+	ret = clock_gettime(PERF_CLOCK, &ts);
+	if (ret)
+		return -1;
+
+	return 0;
+}
+
+static inline uint64_t
+timespec_to_ns(const struct timespec *ts)
+{
+        return ((uint64_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
+}
+
+static inline uint64_t
+perf_get_timestamp(void)
+{
+	struct timespec ts;
+	int ret;
+
+	ret = clock_gettime(PERF_CLOCK, &ts);
+	if (ret)
+		return 0;
+
+	return timespec_to_ns(&ts);
+}
+
+static int
+debug_cache_init(void)
+{
+	char str[32];
+	char *base, *p;
+	struct tm tm;
+	time_t t;
+	int ret;
+
+	time(&t);
+	localtime_r(&t, &tm);
+
+	base = getenv("JITDUMPDIR");
+	if (!base)
+		base = getenv("HOME");
+	if (!base)
+		base = ".";
+
+	strftime(str, sizeof(str), JIT_LANG"-jit-%Y%m%d", &tm);
+
+	snprintf(jit_path, PATH_MAX - 1, "%s/.debug/", base);
+
+	ret = mkdir(jit_path, 0755);
+	if (ret == -1) {
+		if (errno != EEXIST) {
+			warn("jvmti: cannot create jit cache dir %s", jit_path);
+			return -1;
+		}
+	}
+
+	snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit", base);
+	ret = mkdir(jit_path, 0755);
+	if (ret == -1) {
+		if (errno != EEXIST) {
+			warn("cannot create jit cache dir %s", jit_path);
+			return -1;
+		}
+	}
+
+	snprintf(jit_path, PATH_MAX - 1, "%s/.debug/jit/%s.XXXXXXXX", base, str);
+
+	p = mkdtemp(jit_path);
+	if (p != jit_path) {
+		warn("cannot create jit cache dir %s", jit_path);
+		return -1;
+	}
+
+	return 0;
+}
+
+void *jvmti_open(void)
+{
+	int pad_cnt;
+	char dump_path[PATH_MAX];
+	struct jitheader header;
+	FILE *fp;
+
+	if (perf_open_timestamp())
+		warnx("jvmti: kernel does not support /dev/trace_clock or permissions are wrong on that device");
+
+	memset(&header, 0, sizeof(header));
+
+	debug_cache_init();
+
+	snprintf(dump_path, PATH_MAX, "%s/jit-%i.dump", jit_path, getpid());
+
+	fp = fopen(dump_path, "w");
+	if (!fp) {
+		warn("jvmti: cannot create %s", dump_path);
+		goto error;
+	}
+
+	warnx("jvmti: jitdump in %s", dump_path);
+
+	if (get_e_machine(&header)) {
+		warn("get_e_machine failed\n");
+		goto error;
+	}
+
+	header.magic      = JITHEADER_MAGIC;
+	header.version    = JITHEADER_VERSION;
+	header.total_size = sizeof(header);
+	header.pid        = getpid();
+
+	/* calculate amount of padding '\0' */
+	pad_cnt = PADDING_8ALIGNED(header.total_size);
+	header.total_size += pad_cnt;
+
+	header.timestamp = perf_get_timestamp();
+
+	if (!fwrite(&header, sizeof(header), 1, fp)) {
+		warn("jvmti: cannot write dumpfile header");
+		goto error;
+	}
+
+	/* write padding '\0' if necessary */
+	if (pad_cnt && !fwrite(pad_bytes, pad_cnt, 1, fp)) {
+		warn("jvmti: cannot write dumpfile header padding");
+		goto error;
+	}
+
+	return fp;
+error:
+	fclose(fp);
+	return NULL;
+}
+
+int
+jvmti_close(void *agent)
+{
+	struct jr_code_close rec;
+	FILE *fp = agent;
+
+	if (!fp) {
+		warnx("jvmti: incalid fd in close_agent");
+		return -1;
+	}
+
+	rec.p.id = JIT_CODE_CLOSE;
+	rec.p.total_size = sizeof(rec);
+
+	rec.p.timestamp = perf_get_timestamp();
+
+	if (!fwrite(&rec, sizeof(rec), 1, fp))
+		return -1;
+
+	fclose(fp);
+
+	fp = NULL;
+
+	return 0;
+}
+
+int jvmti_write_code(void *agent, char const *sym,
+	uint64_t vma, void const *code, unsigned int const size)
+{
+	static int code_generation = 1;
+	struct jr_code_load rec;
+	size_t sym_len;
+	size_t padding_count;
+	FILE *fp = agent;
+	int ret = -1;
+
+	/* don't care about 0 length function, no samples */
+	if (size == 0)
+		return 0;
+
+	if (!fp) {
+		warnx("jvmti: invalid fd in write_native_code");
+		return -1;
+	}
+
+	sym_len = strlen(sym) + 1;
+
+	rec.p.id           = JIT_CODE_LOAD;
+	rec.p.total_size   = sizeof(rec) + sym_len;
+	padding_count      = PADDING_8ALIGNED(rec.p.total_size);
+	rec.p. total_size += padding_count;
+	rec.p.timestamp    = perf_get_timestamp();
+
+	rec.code_size  = size;
+	rec.vma        = vma;
+	rec.code_addr  = vma;
+	rec.pid	       = getpid();
+	rec.tid	       = gettid();
+	rec.code_index = code_generation++;
+
+	if (code)
+		rec.p.total_size += size;
+
+	/*
+	 * If JVM is multi-threaded, nultiple concurrent calls to agent
+	 * may be possible, so protect file writes
+	 */
+	flockfile(fp);
+
+	ret = fwrite_unlocked(&rec, sizeof(rec), 1, fp);
+	fwrite_unlocked(sym, sym_len, 1, fp);
+	if (code)
+		fwrite_unlocked(code, size, 1, fp);
+
+	if (padding_count)
+		fwrite_unlocked(pad_bytes, padding_count, 1, fp);
+
+	funlockfile(fp);
+
+	ret = 0;
+
+	return ret;
+}
diff --git a/tools/perf/jvmti/jvmti_agent.h b/tools/perf/jvmti/jvmti_agent.h
new file mode 100644
index 0000000..54e5c5e
--- /dev/null
+++ b/tools/perf/jvmti/jvmti_agent.h
@@ -0,0 +1,23 @@
+#ifndef __JVMTI_AGENT_H__
+#define __JVMTI_AGENT_H__
+
+#include <sys/types.h>
+#include <stdint.h>
+
+#define __unused __attribute__((unused))
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+void *jvmti_open(void);
+int   jvmti_close(void *agent);
+int   jvmti_write_code(void *agent, char const *symbol_name,
+		       uint64_t vma, void const *code,
+		       const unsigned int code_size);
+
+#if defined(__cplusplus)
+}
+
+#endif
+#endif /* __JVMTI_H__ */
diff --git a/tools/perf/jvmti/libjvmti.c b/tools/perf/jvmti/libjvmti.c
new file mode 100644
index 0000000..8b8d782
--- /dev/null
+++ b/tools/perf/jvmti/libjvmti.c
@@ -0,0 +1,149 @@
+#include <sys/types.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <err.h>
+#include <jvmti.h>
+
+#include "jvmti_agent.h"
+
+void *jvmti_agent;
+
+static void JNICALL
+compiled_method_load_cb(jvmtiEnv *jvmti,
+			jmethodID method,
+			jint code_size,
+			void const *code_addr,
+			jint map_length,
+			jvmtiAddrLocationMap const *map,
+			void const *compile_info __unused)
+{
+	jclass decl_class;
+	char *class_sign = NULL;
+	char *func_name = NULL;
+	char *func_sign = NULL;
+	jvmtiError ret;
+	size_t len;
+
+	ret = (*jvmti)->GetMethodDeclaringClass(jvmti, method,
+						&decl_class);
+	if (ret != JVMTI_ERROR_NONE) {
+		warnx("jvmti: getmethoddeclaringclass failed");
+		return;
+	}
+
+	ret = (*jvmti)->GetClassSignature(jvmti, decl_class,
+					  &class_sign, NULL);
+	if (ret != JVMTI_ERROR_NONE) {
+		warnx("jvmti: getclassignature failed");
+		goto error;
+	}
+
+	ret = (*jvmti)->GetMethodName(jvmti, method, &func_name,
+				      &func_sign, NULL);
+	if (ret != JVMTI_ERROR_NONE) {
+		warnx("jvmti: failed getmethodname");
+		goto error;
+	}
+
+	len = strlen(func_name) + strlen(class_sign) + strlen(func_sign) + 2;
+
+	{
+		char str[len];
+		uint64_t addr = (uint64_t)(unsigned long)code_addr;
+		snprintf(str, len, "%s%s%s", class_sign, func_name, func_sign);
+		ret = jvmti_write_code(jvmti_agent, str, addr, code_addr, code_size);
+		if (ret)
+			warnx("jvmti: write_code() failed");
+	}
+error:
+	(*jvmti)->Deallocate(jvmti, (unsigned char *)func_name);
+	(*jvmti)->Deallocate(jvmti, (unsigned char *)func_sign);
+	(*jvmti)->Deallocate(jvmti, (unsigned char *)class_sign);
+}
+
+static void JNICALL
+code_generated_cb(jvmtiEnv *jvmti,
+		  char const *name,
+		  void const *code_addr,
+		  jint code_size)
+{
+	uint64_t addr = (uint64_t)(unsigned long)code_addr;
+	int ret;
+
+	ret = jvmti_write_code(jvmti_agent, name, addr, code_addr, code_size);
+	if (ret)
+		warnx("jvmti: write_code() failed for code_generated");
+}
+
+JNIEXPORT jint JNICALL
+Agent_OnLoad(JavaVM *jvm, char *options, void *reserved __unused)
+{
+	jvmtiEventCallbacks cb;
+	jvmtiCapabilities caps1;
+	jvmtiEnv *jvmti = NULL;
+	jint ret;
+
+	jvmti_agent = jvmti_open();
+	if (!jvmti_agent) {
+		warnx("jvmti: open_agent failed");
+		return -1;
+	}
+
+	/*
+	 * Request a JVMTI interface version 1 environment
+	 */
+	ret = (*jvm)->GetEnv(jvm, (void *)&jvmti, JVMTI_VERSION_1);
+	if (ret != JNI_OK) {
+		warnx("jvmti: jvmti version 1 not supported");
+		return -1;
+	}
+
+	/*
+	 * acquire method_load capability, we require it
+	 */
+	memset(&caps1, 0, sizeof(caps1));
+	caps1.can_generate_compiled_method_load_events = 1;
+
+	ret = (*jvmti)->AddCapabilities(jvmti, &caps1);
+	if (ret != JVMTI_ERROR_NONE) {
+		warnx("jvmti: acquire compiled_method capability failed");
+		return -1;
+	}
+
+	memset(&cb, 0, sizeof(cb));
+
+	cb.CompiledMethodLoad   = compiled_method_load_cb;
+	cb.DynamicCodeGenerated = code_generated_cb;
+
+	ret = (*jvmti)->SetEventCallbacks(jvmti, &cb, sizeof(cb));
+	if (ret != JVMTI_ERROR_NONE) {
+		warnx("jvmti: cannot set event callbacks");
+		return -1;
+	}
+
+	ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
+			JVMTI_EVENT_COMPILED_METHOD_LOAD, NULL);
+	if (ret != JVMTI_ERROR_NONE) {
+		warnx("jvmti: setnotification failed for method_load");
+		return -1;
+	}
+
+	ret = (*jvmti)->SetEventNotificationMode(jvmti, JVMTI_ENABLE,
+			JVMTI_EVENT_DYNAMIC_CODE_GENERATED, NULL);
+	if (ret != JVMTI_ERROR_NONE) {
+		warnx("jvmti: setnotification failed on code_generated");
+		return -1;
+	}
+	return 0;
+}
+
+JNIEXPORT void JNICALL
+Agent_OnUnload(JavaVM *jvm __unused)
+{
+	int ret;
+
+	ret = jvmti_close(jvmti_agent);
+	if (ret)
+		errx(1, "Error: op_close_agent()");
+}
-- 
1.9.1

[PATCH v2 4/4] clock: add perf_clock posix clock

[Stephane Eranian]

This patch is a re-packaging of David's Ahern
posix perf clock available here:

	https://github.com/dsahern/linux/blob/perf-full-monty/README.ahern

The patch itself is based on Pawel Moll's original post:

	https://lkml.org/lkml/2013/3/14/523

The new clock is call PERF_CLOCK. To use it

	#include <time.h>
	#include <linux/time.h>

	struct timespec ts;

	clock_gettime(PERF_CLOCK, &ts);

Signed-off-by: Stephane Eranian <eranian@google.com>
---
 include/uapi/linux/time.h      |  1 +
 kernel/time/Kconfig            |  6 +++++
 kernel/time/Makefile           |  1 +
 kernel/time/perf_posix_clock.c | 54 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 62 insertions(+)
 create mode 100644 kernel/time/perf_posix_clock.c

diff --git a/include/uapi/linux/time.h b/include/uapi/linux/time.h
index e75e1b6..9066bf0 100644
--- a/include/uapi/linux/time.h
+++ b/include/uapi/linux/time.h
@@ -56,6 +56,7 @@ struct itimerval {
 #define CLOCK_BOOTTIME_ALARM		9
 #define CLOCK_SGI_CYCLE			10	/* Hardware specific */
 #define CLOCK_TAI			11
+#define CLOCK_PERF			12
 
 #define MAX_CLOCKS			16
 #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
index d626dc9..6e4b707 100644
--- a/kernel/time/Kconfig
+++ b/kernel/time/Kconfig
@@ -201,5 +201,11 @@ config HIGH_RES_TIMERS
 	  hardware is not capable then this option only increases
 	  the size of the kernel image.
 
+config PERF_CLOCK
+	tristate "Perf_events posix clock timer source"
+	help
+	  This option adds a new posix clock timer source which uses the same time
+	  source as the perf_events subsystem. It makes it possible to correlate
+          user level samples with perf_events samples.
 endmenu
 endif
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index f622cf2..41cd183 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_TICK_ONESHOT)			+= tick-sched.o
 obj-$(CONFIG_TIMER_STATS)			+= timer_stats.o
 obj-$(CONFIG_DEBUG_FS)				+= timekeeping_debug.o
 obj-$(CONFIG_TEST_UDELAY)			+= test_udelay.o
+obj-$(CONFIG_PERF_CLOCK)			+= perf_posix_clock.o
 
 $(obj)/time.o: $(obj)/timeconst.h
 
diff --git a/kernel/time/perf_posix_clock.c b/kernel/time/perf_posix_clock.c
new file mode 100644
index 0000000..03c58b2
--- /dev/null
+++ b/kernel/time/perf_posix_clock.c
@@ -0,0 +1,54 @@
+/*
+ * Implements CLOCK_PERF.
+ *
+ * perf_clock is not exported, but for as long as I can remember perf_clock
+ * is local_clock which is exported. Make use of that.
+ *
+ * posix clock implementation by Pawel Moll
+ *     https://lkml.org/lkml/2013/3/14/523
+ *
+ * module by David Ahern, December 2013
+ */
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/posix-timers.h>
+
+static int perf_posix_clock_getres(const clockid_t which_clock,
+	                struct timespec *tp)
+{
+	*tp = ns_to_timespec(TICK_NSEC);
+	return 0;
+}
+
+static int perf_posix_clock_get(clockid_t which_clock, struct timespec *tp)
+{
+	*tp = ns_to_timespec(local_clock());
+	return 0;
+}
+
+
+static struct k_clock perf_posix_clock = {
+	.clock_getres = perf_posix_clock_getres,
+	.clock_get = perf_posix_clock_get,
+};
+
+static int perf_posix_clock_init(void)
+{
+	/* register this character driver */
+	posix_timers_register_clock(CLOCK_PERF, &perf_posix_clock);
+
+	printk(KERN_INFO "perf_clock clock registered\n");
+
+	/* no API to unregister a clock so this module cannot be unloaded */
+	__module_get(THIS_MODULE);
+
+	return 0;
+}
+
+module_init(perf_posix_clock_init);
+
+MODULE_AUTHOR("David Ahern");
+MODULE_LICENSE("GPL");
-- 
1.9.1

Re: [PATCH v2 0/4] perf: add support for profiling jitted code

[Ingo Molnar]

* Stephane Eranian <eranian@google.com> wrote:

> The current support only works when the runtime is 
> monitored from start to finish: perf record java 
> --agenpath:libpfmjvmti.so my_class.

Could we add '--agenpath:libpfmjvmti.so' automatically if a 
binary called 'java' is recorded?

( With a --nojavajit flag to not do that, should someone
  feel like having a 'java' executable that doesn't accept
  the --agenpath flag, or so? Assuming the major JVMs 
  accept the --agenpath flag. )

> Once the run is completed, the jitdump file needs to be 
> injected into the perf.data file. This is accomplished by 
> using the perf inject command. This will also generate an 
> ELF image for each jitted function. The inject MMAP 
> records will point to those ELF images. The reasoning 
> behind using ELF images is that it makes processing for 
> perf report and annotate automatic and transparent. It 
> also makes it easier to package and analyze on a remote 
> machine.

So it would be nice if this part was automatic, i.e. if I 
could just profile a java run with the regular perf 
profiling flow.

> The reporting is unchanged, simply invoke perf report or 
> perf annotate on the modified perf.data file. The jitted 
> code will appear symbolized and the assembly view will 
> display the instruction level profile!
> 
> As an added bonus, the series includes support for 
> demangling function signature from OpenJDK.

Cool!

> Furthermore, we believe there is a way to skip the perf 
> inject phase and have perf report/annotate directly 
> inject the MMAP records on the fly during processing of 
> the perf.data file. Perf report would also generate the 
> ELF files if necessary. Such optimization, would make 
> using this extension seamless in system-wide mode and 
> larger environments. This will be added in a later update 
> as well.

I think angling for seemless operation is really important.

> To use the new feature:
>   - compile and install the perf_posix_clock.ko module:
>     - make modules (say M to PERF_CLOCK config option)
>     - make modules_install;
>     - modprobe perf_posix_clock
>     - dmesg should say: perf_clock clock registered
>   - compile perf
>   - cd tools/perf/jvmti; make; install wherever is appropriate

Will 'make -C tools/perf install' DTRT, or is the last step 
needed separately?

Thanks,

	Ingo

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[Ingo Molnar]

* Stephane Eranian <eranian@google.com> wrote:

> This patch is a re-packaging of David's Ahern
> posix perf clock available here:
> 
> 	https://github.com/dsahern/linux/blob/perf-full-monty/README.ahern
> 
> The patch itself is based on Pawel Moll's original post:
> 
> 	https://lkml.org/lkml/2013/3/14/523
> 
> The new clock is call PERF_CLOCK. To use it
> 
> 	#include <time.h>
> 	#include <linux/time.h>
> 
> 	struct timespec ts;
> 
> 	clock_gettime(PERF_CLOCK, &ts);

So what's the justification for this new clock, as opposed 
to say CLOCK_MONOTONIC?

Thanks,

	Ingo

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[John Stultz]

On Wed, Feb 18, 2015 at 9:21 AM, Stephane Eranian <eranian@google.com> wrote:
> This patch is a re-packaging of David's Ahern
> posix perf clock available here:
>
>         https://github.com/dsahern/linux/blob/perf-full-monty/README.ahern
>
> The patch itself is based on Pawel Moll's original post:
>
>         https://lkml.org/lkml/2013/3/14/523
>
> The new clock is call PERF_CLOCK. To use it
>
>         #include <time.h>
>         #include <linux/time.h>
>
>         struct timespec ts;
>
>         clock_gettime(PERF_CLOCK, &ts);

I'd still strongly recommend against exposing the perf clock to
userspace this way.  The time domain isn't clearly different from
something like CLOCK_MONOTONIC_RAW and doesn't really have well
defined behavior. We're just exporting "whatever the kernel does
internally" to userspace, and in the past similar internal use clocks
like the sched_clock have changed their behavior, so I'm not confident
the perf clock is really baked enough (including cross architectures)
to make it part of the ABI.

Pawel and others have continued to work on other approaches that allow
for perf events to be interpolated to, or use CLOCK_MONOTONIC itself,
which I don't object to, so you might want to follow up on those?

thanks
-john

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[Stephane Eranian]

On Wed, Feb 18, 2015 at 1:00 PM, John Stultz <john.stultz@linaro.org> wrote:
> On Wed, Feb 18, 2015 at 9:21 AM, Stephane Eranian <eranian@google.com> wrote:
>> This patch is a re-packaging of David's Ahern
>> posix perf clock available here:
>>
>>         https://github.com/dsahern/linux/blob/perf-full-monty/README.ahern
>>
>> The patch itself is based on Pawel Moll's original post:
>>
>>         https://lkml.org/lkml/2013/3/14/523
>>
>> The new clock is call PERF_CLOCK. To use it
>>
>>         #include <time.h>
>>         #include <linux/time.h>
>>
>>         struct timespec ts;
>>
>>         clock_gettime(PERF_CLOCK, &ts);
>
> I'd still strongly recommend against exposing the perf clock to
> userspace this way.  The time domain isn't clearly different from
> something like CLOCK_MONOTONIC_RAW and doesn't really have well
> defined behavior. We're just exporting "whatever the kernel does
> internally" to userspace, and in the past similar internal use clocks
> like the sched_clock have changed their behavior, so I'm not confident
> the perf clock is really baked enough (including cross architectures)
> to make it part of the ABI.
>
> Pawel and others have continued to work on other approaches that allow
> for perf events to be interpolated to, or use CLOCK_MONOTONIC itself,
> which I don't object to, so you might want to follow up on those?
>
Personally, I don't have a preference. I want something that is EASY to
correlate to the perf_events timestamp and that is PORTABLE across
architectures. Where is the patch that uses CLOCK_MONOTONIC?
I assume it changes the clock used by perf_events and I further assume
this clock can be read from NMI context (without requiring locking).

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[David Ahern]

On 2/18/15 11:00 AM, John Stultz wrote:
> I'd still strongly recommend against exposing the perf clock to
> userspace this way.  The time domain isn't clearly different from
> something like CLOCK_MONOTONIC_RAW and doesn't really have well
> defined behavior. We're just exporting "whatever the kernel does
> internally" to userspace, and in the past similar internal use clocks
> like the sched_clock have changed their behavior, so I'm not confident
> the perf clock is really baked enough (including cross architectures)
> to make it part of the ABI.
>
> Pawel and others have continued to work on other approaches that allow
> for perf events to be interpolated to, or use CLOCK_MONOTONIC itself,
> which I don't object to, so you might want to follow up on those?

AFAIK Stephane is not proposing this patch for inclusion but rather it 
is an unfortunate necessary evil. The module exposes perf_clock (ie., 
local_clock) to userspace and allows in this case the generation of 
samples with a perf timestamp which is required for proper sorting.

I understand this solution is not liked, but it works, requires no 
kernel modifications to achieve the end goal and can be used for kernels 
going back to at least 2.6.38 (perhaps earlier, have not checked).

David

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[John Stultz]

On Wed, Feb 18, 2015 at 10:10 AM, Stephane Eranian <eranian@google.com> wrote:
> On Wed, Feb 18, 2015 at 1:00 PM, John Stultz <john.stultz@linaro.org> wrote:
>> On Wed, Feb 18, 2015 at 9:21 AM, Stephane Eranian <eranian@google.com> wrote:
>>> This patch is a re-packaging of David's Ahern
>>> posix perf clock available here:
>>>
>>>         https://github.com/dsahern/linux/blob/perf-full-monty/README.ahern
>>>
>>> The patch itself is based on Pawel Moll's original post:
>>>
>>>         https://lkml.org/lkml/2013/3/14/523
>>>
>>> The new clock is call PERF_CLOCK. To use it
>>>
>>>         #include <time.h>
>>>         #include <linux/time.h>
>>>
>>>         struct timespec ts;
>>>
>>>         clock_gettime(PERF_CLOCK, &ts);
>>
>> I'd still strongly recommend against exposing the perf clock to
>> userspace this way.  The time domain isn't clearly different from
>> something like CLOCK_MONOTONIC_RAW and doesn't really have well
>> defined behavior. We're just exporting "whatever the kernel does
>> internally" to userspace, and in the past similar internal use clocks
>> like the sched_clock have changed their behavior, so I'm not confident
>> the perf clock is really baked enough (including cross architectures)
>> to make it part of the ABI.
>>
>> Pawel and others have continued to work on other approaches that allow
>> for perf events to be interpolated to, or use CLOCK_MONOTONIC itself,
>> which I don't object to, so you might want to follow up on those?
>>
> Personally, I don't have a preference. I want something that is EASY to
> correlate to the perf_events timestamp and that is PORTABLE across
> architectures. Where is the patch that uses CLOCK_MONOTONIC?
> I assume it changes the clock used by perf_events and I further assume
> this clock can be read from NMI context (without requiring locking).

I believe it can be found here:
https://lkml.org/lkml/2015/1/21/711

thanks
-john

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[John Stultz]

On Wed, Feb 18, 2015 at 10:11 AM, David Ahern <dsahern@gmail.com> wrote:
> On 2/18/15 11:00 AM, John Stultz wrote:
>>
>> I'd still strongly recommend against exposing the perf clock to
>> userspace this way.  The time domain isn't clearly different from
>> something like CLOCK_MONOTONIC_RAW and doesn't really have well
>> defined behavior. We're just exporting "whatever the kernel does
>> internally" to userspace, and in the past similar internal use clocks
>> like the sched_clock have changed their behavior, so I'm not confident
>> the perf clock is really baked enough (including cross architectures)
>> to make it part of the ABI.
>>
>> Pawel and others have continued to work on other approaches that allow
>> for perf events to be interpolated to, or use CLOCK_MONOTONIC itself,
>> which I don't object to, so you might want to follow up on those?
>
>
> AFAIK Stephane is not proposing this patch for inclusion but rather it is an
> unfortunate necessary evil. The module exposes perf_clock (ie., local_clock)
> to userspace and allows in this case the generation of samples with a perf
> timestamp which is required for proper sorting.
>
> I understand this solution is not liked, but it works, requires no kernel
> modifications to achieve the end goal and can be used for kernels going back
> to at least 2.6.38 (perhaps earlier, have not checked).

Yep. And I'm sympathetic to the fact that an alternative solution
hasn't made it upstream yet. I'm hopeful Pawel's recent approach will
make it in (it seems like it hasn't raised any flags w/ scheduler
folks - but I've not always been able to follow the discussion
closely).

thanks
-john

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[Stephane Eranian]

On Wed, Feb 18, 2015 at 1:18 PM, John Stultz <john.stultz@linaro.org> wrote:
> On Wed, Feb 18, 2015 at 10:11 AM, David Ahern <dsahern@gmail.com> wrote:
>> On 2/18/15 11:00 AM, John Stultz wrote:
>>>
>>> I'd still strongly recommend against exposing the perf clock to
>>> userspace this way.  The time domain isn't clearly different from
>>> something like CLOCK_MONOTONIC_RAW and doesn't really have well
>>> defined behavior. We're just exporting "whatever the kernel does
>>> internally" to userspace, and in the past similar internal use clocks
>>> like the sched_clock have changed their behavior, so I'm not confident
>>> the perf clock is really baked enough (including cross architectures)
>>> to make it part of the ABI.
>>>
>>> Pawel and others have continued to work on other approaches that allow
>>> for perf events to be interpolated to, or use CLOCK_MONOTONIC itself,
>>> which I don't object to, so you might want to follow up on those?
>>
>>
>> AFAIK Stephane is not proposing this patch for inclusion but rather it is an
>> unfortunate necessary evil. The module exposes perf_clock (ie., local_clock)
>> to userspace and allows in this case the generation of samples with a perf
>> timestamp which is required for proper sorting.
>>
>> I understand this solution is not liked, but it works, requires no kernel
>> modifications to achieve the end goal and can be used for kernels going back
>> to at least 2.6.38 (perhaps earlier, have not checked).
>
> Yep. And I'm sympathetic to the fact that an alternative solution
> hasn't made it upstream yet. I'm hopeful Pawel's recent approach will
> make it in (it seems like it hasn't raised any flags w/ scheduler
> folks - but I've not always been able to follow the discussion
> closely).
>
Ok, let me try switching my series to Pawel's patch then. Should not take long.

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[Ingo Molnar]

* John Stultz <john.stultz@linaro.org> wrote:

> > AFAIK Stephane is not proposing this patch for 
> > inclusion but rather it is an unfortunate necessary 
> > evil. The module exposes perf_clock (ie., local_clock) 
> > to userspace and allows in this case the generation of 
> > samples with a perf timestamp which is required for 
> > proper sorting.
> >
> > I understand this solution is not liked, but it works, 
> > requires no kernel modifications to achieve the end 
> > goal and can be used for kernels going back to at least 
> > 2.6.38 (perhaps earlier, have not checked).
> 
> Yep. And I'm sympathetic to the fact that an alternative 
> solution hasn't made it upstream yet. I'm hopeful Pawel's 
> recent approach will make it in (it seems like it hasn't 
> raised any flags w/ scheduler folks - but I've not always 
> been able to follow the discussion closely).

So if it's part of this series and reviews fine then I'll 
be happy to apply it! Nothing better than having a kernel 
patch and an actual usecase go hand in hand.

Thanks,

	Ingo

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[Paul Bolle]

Whitespace trivialities follow.

On Wed, 2015-02-18 at 18:21 +0100, Stephane Eranian wrote:
> This patch is a re-packaging of David's Ahern
> posix perf clock available here:
> 
> 	https://github.com/dsahern/linux/blob/perf-full-monty/README.ahern
> 
> The patch itself is based on Pawel Moll's original post:
> 
> 	https://lkml.org/lkml/2013/3/14/523
> 
> The new clock is call PERF_CLOCK. To use it
> 
> 	#include <time.h>
> 	#include <linux/time.h>
> 
> 	struct timespec ts;
> 
> 	clock_gettime(PERF_CLOCK, &ts);
> 
> Signed-off-by: Stephane Eranian <eranian@google.com>
> ---
>  include/uapi/linux/time.h      |  1 +
>  kernel/time/Kconfig            |  6 +++++
>  kernel/time/Makefile           |  1 +
>  kernel/time/perf_posix_clock.c | 54 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 62 insertions(+)
>  create mode 100644 kernel/time/perf_posix_clock.c
> 
> diff --git a/include/uapi/linux/time.h b/include/uapi/linux/time.h
> index e75e1b6..9066bf0 100644
> --- a/include/uapi/linux/time.h
> +++ b/include/uapi/linux/time.h
> @@ -56,6 +56,7 @@ struct itimerval {
>  #define CLOCK_BOOTTIME_ALARM		9
>  #define CLOCK_SGI_CYCLE			10	/* Hardware specific */
>  #define CLOCK_TAI			11
> +#define CLOCK_PERF			12
>  
>  #define MAX_CLOCKS			16
>  #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
> diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
> index d626dc9..6e4b707 100644
> --- a/kernel/time/Kconfig
> +++ b/kernel/time/Kconfig
> @@ -201,5 +201,11 @@ config HIGH_RES_TIMERS
>  	  hardware is not capable then this option only increases
>  	  the size of the kernel image.
>  
> +config PERF_CLOCK
> +	tristate "Perf_events posix clock timer source"
> +	help
> +	  This option adds a new posix clock timer source which uses the same time
> +	  source as the perf_events subsystem. It makes it possible to correlate
> +          user level samples with perf_events samples.

Tab and two spaces followed by an empty line here, please.

>  endmenu
>  endif

Thanks,


Paul Bolle

Re: [PATCH v2 4/4] clock: add perf_clock posix clock

[Paul Bolle]

[s/pawell.moll/pawel.moll/]

On Wed, 2015-02-18 at 18:21 +0100, Stephane Eranian wrote:
> This patch is a re-packaging of David's Ahern
> posix perf clock available here:
> 
> 	https://github.com/dsahern/linux/blob/perf-full-monty/README.ahern
> 
> The patch itself is based on Pawel Moll's original post:
> 
> 	https://lkml.org/lkml/2013/3/14/523
> 
> The new clock is call PERF_CLOCK. To use it
> 
> 	#include <time.h>
> 	#include <linux/time.h>
> 
> 	struct timespec ts;
> 
> 	clock_gettime(PERF_CLOCK, &ts);
> 
> Signed-off-by: Stephane Eranian <eranian@google.com>
> ---
>  include/uapi/linux/time.h      |  1 +
>  kernel/time/Kconfig            |  6 +++++
>  kernel/time/Makefile           |  1 +
>  kernel/time/perf_posix_clock.c | 54 ++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 62 insertions(+)
>  create mode 100644 kernel/time/perf_posix_clock.c
> 
> diff --git a/include/uapi/linux/time.h b/include/uapi/linux/time.h
> index e75e1b6..9066bf0 100644
> --- a/include/uapi/linux/time.h
> +++ b/include/uapi/linux/time.h
> @@ -56,6 +56,7 @@ struct itimerval {
>  #define CLOCK_BOOTTIME_ALARM		9
>  #define CLOCK_SGI_CYCLE			10	/* Hardware specific */
>  #define CLOCK_TAI			11
> +#define CLOCK_PERF			12
>  
>  #define MAX_CLOCKS			16
>  #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
> diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig
> index d626dc9..6e4b707 100644
> --- a/kernel/time/Kconfig
> +++ b/kernel/time/Kconfig
> @@ -201,5 +201,11 @@ config HIGH_RES_TIMERS
>  	  hardware is not capable then this option only increases
>  	  the size of the kernel image.
>  
> +config PERF_CLOCK
> +	tristate "Perf_events posix clock timer source"
> +	help
> +	  This option adds a new posix clock timer source which uses the same time
> +	  source as the perf_events subsystem. It makes it possible to correlate
> +          user level samples with perf_events samples.
>  endmenu
>  endif
> diff --git a/kernel/time/Makefile b/kernel/time/Makefile
> index f622cf2..41cd183 100644
> --- a/kernel/time/Makefile
> +++ b/kernel/time/Makefile
> @@ -14,6 +14,7 @@ obj-$(CONFIG_TICK_ONESHOT)			+= tick-sched.o
>  obj-$(CONFIG_TIMER_STATS)			+= timer_stats.o
>  obj-$(CONFIG_DEBUG_FS)				+= timekeeping_debug.o
>  obj-$(CONFIG_TEST_UDELAY)			+= test_udelay.o
> +obj-$(CONFIG_PERF_CLOCK)			+= perf_posix_clock.o
>  
>  $(obj)/time.o: $(obj)/timeconst.h
>  
> diff --git a/kernel/time/perf_posix_clock.c b/kernel/time/perf_posix_clock.c
> new file mode 100644
> index 0000000..03c58b2
> --- /dev/null
> +++ b/kernel/time/perf_posix_clock.c
> @@ -0,0 +1,54 @@
> +/*
> + * Implements CLOCK_PERF.
> + *
> + * perf_clock is not exported, but for as long as I can remember perf_clock
> + * is local_clock which is exported. Make use of that.
> + *
> + * posix clock implementation by Pawel Moll
> + *     https://lkml.org/lkml/2013/3/14/523
> + *
> + * module by David Ahern, December 2013
> + */
> +#include <linux/version.h>
> +#include <linux/module.h>
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/time.h>
> +#include <linux/posix-timers.h>
> +
> +static int perf_posix_clock_getres(const clockid_t which_clock,
> +	                struct timespec *tp)
> +{
> +	*tp = ns_to_timespec(TICK_NSEC);
> +	return 0;
> +}
> +
> +static int perf_posix_clock_get(clockid_t which_clock, struct timespec *tp)
> +{
> +	*tp = ns_to_timespec(local_clock());
> +	return 0;
> +}
> +
> +
> +static struct k_clock perf_posix_clock = {
> +	.clock_getres = perf_posix_clock_getres,
> +	.clock_get = perf_posix_clock_get,
> +};
> +
> +static int perf_posix_clock_init(void)
> +{
> +	/* register this character driver */
> +	posix_timers_register_clock(CLOCK_PERF, &perf_posix_clock);
> +
> +	printk(KERN_INFO "perf_clock clock registered\n");
> +
> +	/* no API to unregister a clock so this module cannot be unloaded */
> +	__module_get(THIS_MODULE);
> +
> +	return 0;
> +}
> +
> +module_init(perf_posix_clock_init);
> +
> +MODULE_AUTHOR("David Ahern");
> +MODULE_LICENSE("GPL");