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Using DTrace-enabled Python in a Joyent Accelerator
Bryan wrote about a presentation he gave at Google (video) where he demo’ed DTrace in Python. While we did the dtrace probes for Ruby 1.8.5 and 1.8.6, I thought I’d show you how to do it on our Accelerators as well.
John Levon at Sun has written about the DTrace probes that he put into Python 2.4 before. So we have somewhere to start.
Let’s get Python 2.4.4 and the DTrace patch
mkdir /a/src/ mkdir /a/1/languages/python244d curl -O http://python.org/ftp/python/2.4.4/Python-2.4.4.tgz tar zxvf Python-2.4.4.tgz curl -O http://cvs.opensolaris.org/source/xref//jds/spec-files/trunk/patches/Python-07-dtrace.diff
The patch expects a directory call Python-new, so let’s create it
cp -R Python-2.4.4 Python-new
Let’s now apply the patch
gpatch -p0 < Python-07-dtrace.diff
The output of this working looks like
patching file Python-new/Include/frameobject.h patching file Python-new/Makefile.pre.in patching file Python-new/Objects/frameobject.c patching file Python-new/Python/ceval.c patching file Python-new/Python/phelper.d patching file Python-new/Python/python.d
Move on in
cd Python-new/
Run configure
./configure --prefix=/a/1/languages/python244d --enable-shared
Now there’s going to be a couple of changes we’re going to make here so the thing builds, because if you type make && make install right now, it’ll fail. First in one way and then when you fix that, another.
Basically we have to bring the patch and Makefile up so that it’s a full 64-bit build (what our gcc compilers default to.
Open up the ustack helper file
nano Python/phelper.d
And take a look right at the top:
#define _SYS_STAT_H #include < stdio.h > #include "pyport.h"
And under the #include
#define _SYS_STAT_H #include < stdio.h > #include < sys/socket.h > #include < sys/socketvar.h > #include "pyport.h"
Now the makefile
# Compiler options OPT= -DNDEBUG -g -O3 -Wall -Wstrict-prototypes BASECFLAGS= -fno-strict-aliasing CFLAGS= $(BASECFLAGS) $(OPT) CPPFLAGS= -I. -I$(srcdir)/Include LDFLAGS= LDLAST= SGI_ABI= CCSHARED= -fPIC LINKFORSHARED=
Add the -m64 flag to LDFLAGS
# Compiler options OPT= -DNDEBUG -g -O3 -Wall -Wstrict-prototypes BASECFLAGS= -fno-strict-aliasing CFLAGS= $(BASECFLAGS) $(OPT) CPPFLAGS= -I. -I$(srcdir)/Include LDFLAGS= -m64 LDLAST= SGI_ABI= CCSHARED= -fPIC LINKFORSHARED=
And finally we’ll add a -64 flag to each of the dtrace compile lines, so that you’re doing a 64-bit build all the way around.
So lines like
dtrace -o $@ -DPHELPER $(DFLAGS) $(CPPFLAGS) -C -G -s $(srcdir)/Python/phelper.d
Become
# grep dtrace Makefile
DTRACE_OBJS=Python/dtrace.o Python/phelper.o
dtrace -o $@ -DPHELPER $(DFLAGS) $(CPPFLAGS) -C -G -64 -s $(srcdir)/Python/phelper.d
dtrace -o $@ $(DFLAGS) -C -64 -h -s $(srcdir)/Python/python.d
Python/dtrace.o: $(srcdir)/Python/python.d Python/ceval.o
dtrace -o $@ $(DFLAGS) -C -G -64 -s $(srcdir)/Python/python.d Python/ceval.o
Let’s build this bad-boy
make make install ln -s /a/1/languages/python244d /a/1/languages/python
Then we can take a simple dtrace script, like John Levon’s pywrites.d and see some stuff:
[jason:/tmp] root# ./pywrites.d -c ‘/a/1/languages/python244d/bin/python -V’
dtrace: script ‘./pywrites.d’ matched 2 probes
Python 2.4.4
dtrace: pid 21213 has exited
CPU ID FUNCTION:NAME 3 2 :END libc.so.1`_write+0xa libc.so.1`_dowrite+0×54 libc.so.1`_ndoprnt+0×2cb6 libc.so.1`fprintf+0×132 libpython2.4.so.1.0`Py_Main+0×48c python`_start+0×6c 1 libc.so.1`_write+0xa libc.so.1`_ndoprnt+0×3535 libc.so.1`fprintf+0×132 libpython2.4.so.1.0`Py_Main+0×48c python`_start+0×6c 1
[jason:/tmp] root# ./pywrites.d -c “/a/1/languages/python244d/bin/django-admin.py startproject jason”
dtrace: script ‘./pywrites.d’ matched 2 probes
dtrace: pid 21812 has exited
CPU ID FUNCTION:NAME 1 2 :END libc.so.1`_write+0xa libc.so.1`_fflush_u+0×34 libc.so.1`fclose+0×6b libpython2.4.so.1.0`file_close+0xbf libpython2.4.so.1.0`PyEval_EvalFrameReal+0×50c8 [ /a/1/languages/python244d/lib/python2.4/site-packages/django/core/management.py:803 (startproject) ] libpython2.4.so.1.0`PyEval_EvalFrame+0×1f libpython2.4.so.1.0`PyEval_EvalFrameReal+0×61dc [ /a/1/languages/python244d/lib/python2.4/site-packages/django/core/management.py:1599 (execute_from_command_line) ] libpython2.4.so.1.0`PyEval_EvalFrame+0×1f libpython2.4.so.1.0`PyEval_EvalCodeEx+0×727 libpython2.4.so.1.0`PyEval_EvalFrameReal+0×5195 [ /a/1/languages/python244d/bin/django-admin.py:5 (?) ] libpython2.4.so.1.0`PyEval_EvalFrame+0×1f libpython2.4.so.1.0`PyEval_EvalCodeEx+0×727 libpython2.4.so.1.0`PyEval_EvalCode+0×36 libpython2.4.so.1.0`PyRun_FileExFlags+0×97 libpython2.4.so.1.0`PyRun_SimpleFileExFlags+0×16f libpython2.4.so.1.0`Py_Main+0xac5 python`_start+0×6c 1 libc.so.1`_write+0xa libc.so.1`_fflush_u+0×34 libc.so.1`fclose+0×6b libpython2.4.so.1.0`file_close+0xbf libpython2.4.so.1.0`PyEval_EvalFrameReal+0×50c8 [ /a/1/languages/python244d/lib/python2.4/site-packages/django/core/management.py:783 (_start_helper) ] libpython2.4.so.1.0`PyEval_EvalFrame+0×1f libpython2.4.so.1.0`PyEval_EvalCodeEx+0×727 libpython2.4.so.1.0`PyEval_EvalFrameReal+0×5195 [ /a/1/languages/python244d/lib/python2.4/site-packages/django/core/management.py:795 (startproject) ] libpython2.4.so.1.0`PyEval_EvalFrame+0×1f libpython2.4.so.1.0`PyEval_EvalFrameReal+0×61dc [ /a/1/languages/python244d/lib/python2.4/site-packages/django/core/management.py:1599 (execute_from_command_line) ] libpython2.4.so.1.0`PyEval_EvalFrame+0×1f libpython2.4.so.1.0`PyEval_EvalCodeEx+0×727 libpython2.4.so.1.0`PyEval_EvalFrameReal+0×5195 [ /a/1/languages/python244d/bin/django-admin.py:5 (?) ] libpython2.4.so.1.0`PyEval_EvalFrame+0×1f libpython2.4.so.1.0`PyEval_EvalCodeEx+0×727 libpython2.4.so.1.0`PyEval_EvalCode+0×36 libpython2.4.so.1.0`PyRun_FileExFlags+0×97 libpython2.4.so.1.0`PyRun_SimpleFileExFlags+0×16f libpython2.4.so.1.0`Py_Main+0xac5 python`_start+0×6c 3 [jason:/tmp] root# ls jason/ init.py manage.py settings.py urls.py
I think I’m going to bring the patch up to Python 2.5 as well.
Commenting is closed for this article.
dtrace -o Python/dtrace.o -C -G -64 -s ./Python/python.d Python/ceval.o
dtrace: failed to link script ./Python/python.d: incorrect ELF class for object file: Python/ceval.o
—-
$ file Python/ceval.o
Python/ceval.o: ELF 32-bit LSB relocatable 80386 Version 1
32-bit?
$ which gcc
/opt/csw/gcc4/bin/gcc
Are you using something else?
Double checked that I had all your changes.
— Brett 330 days ago #Simply awesome. I’ll definitely be needing this in short order! Thanks for the details on how to get it rolling.
— Jonathan LaCour 330 days ago #Neat. I’m curious why you need sys/socket{var}.h in
the helper file?
If you use gpatch -p1, you don’t need a new directory.
You should be able to do
make DFLAGS=”-64”
and similarly for LDFLAGS etc to get the 64-bit build.
It’s worth looking at the spec file:
http://cvs.opensolaris.org/source/xref//jds/spec-files/trunk/SUNWPython.spec
We’re upgrading to Python 2.5 in Solaris “soon”, and the patch will get updated as needed then.
— John Levon 330 days ago #@Brett, I used gcc 3 at /usr/sfw/bin/gcc
— Jason A. Hoffman 330 days ago #Might I suggest adding pre { overflow: auto; } to your css.
— James 329 days ago #@ john, there was some odd, and yes I know about the flags passed to makefiles. I just wanted the post to be a bit more education (at least attempted). For the sys/socket{var}.h, the build failed with some time error (I forget the exact one but can reproduce it)
@ james, good idear, will do
— Jason A. Hoffman 329 days ago #@james, the pre funniness was my fault, I had a < pre ; as tag
— Jason A. Hoffman 329 days ago #