[lttng-dev] LTTNG on Android ICS

Ionut D. ionut5001 at gmail.com
Fri May 24 04:07:10 EDT 2013 

Hello,

Thank you for the slides. I manged to build the kernel modules and I insmod
them manually. On the device I copied in /data/lttng following binaries
`lttng`, `lttng-relayd` and `lttng-sessiond`. If I execute `./lttng list
-k` it shows me a list of available kernel events. I create a session
called mysession with `./lttng create mysession` and I enable tracing on
all the event with `./lttng enable-event -a -k`. But here starts my problem.

The output of the last command is the following:

root at android:/data/lttng # ./lttng enable-event -a -k
PERROR [3681/3681]: kernel start consumer exec: (null) (in
spawn_consumerd() at main.c:2007)
Error: Condition timed out. The consumer thread was never ready. Killing it
Warning: Using pthread_kill as pthread_cancel is missing on the current
platform
PERROR [3608/3658]: write poll pipe: (null) (in notify_thread_pipe() at
utils.c:43)
Error: Events: Fatal error of the session daemon (channel channel0, session
mysession)

Do you have any idea about what could be wrong? What options should I check
in the kernel configuration? (I checked all that is under Tracing)

--Ionut





On Thu, May 23, 2013 at 6:09 PM, Charles Brière
<charles.briere at polymtl.ca>wrote:

> Module location doesn't really matter, we used to push them to /data/...
> or /sdcard/... .
>
> Modprobe doesn't exists on Android so you'll need to use insmod. We used this
> script <https://docs.google.com/file/d/0B56W2viIJ4oqOU1qTHJZY0V2MzQ/edit>in order to compile, push to device and load modules.
>
> We also made a presentation you might be interested in that can be viewed
> on
> https://docs.google.com/presentation/d/14lte2AchEAyxMk3WSQ53SdbBm2tfmABBFQojuUhxg7Y/pub?start=false&loop=false&delayms=3000
>
>
> On Thu, May 23, 2013 at 10:40 AM, Ionut D. <ionut5001 at gmail.com> wrote:
>
>> About the kernel modules. Where should they be located on the target?
>> Should I have modprobe or insmod it is enough?
>>
>>
>> On Thu, May 23, 2013 at 2:19 PM, Ionut D. <ionut5001 at gmail.com> wrote:
>>
>>> Sorry for my late response. At the end after different some adds
>>> (defines in libc) I managed to compile them for ICS with NDK r7c. I was a
>>> problem of environment.
>>>
>>>
>>> On Tue, May 21, 2013 at 9:26 PM, Pierre-Luc St-Charles <
>>> pierre-luc.st-charles at polymtl.ca> wrote:
>>>
>>>> Well, I cannot get my hands on a R7 NDK this very moment, but I'm
>>>> surprised there are no grep hits in the ./platforms/android-XX/arch-arm
>>>> directory; can you verify that the NDK you have does include an ARM
>>>> architecture sysroot? That's the the one you should be compiling with, and
>>>> I believe you'll find the asm/unistd.h header there (as there is no 32/64
>>>> bit difference on Android+ARM yet).
>>>>
>>>>
>>>> On Tue, May 21, 2013 at 11:29 AM, Ionut D. <ionut5001 at gmail.com> wrote:
>>>>
>>>>> The problem is that I am trying to build it on ICS with NDK r7 and I
>>>>> tried to build it in the both ways with the ndk and also by creating
>>>>> Android.mk files and it looks like is not working. I searched with grep
>>>>> firstly through NDK and second through bionic and these are the results:
>>>>>
>>>>> NDK:
>>>>> #grep -r __NR_splice .
>>>>> ./platforms/android-9/arch-x86/usr/include/asm/unistd_32.h:#define
>>>>> __NR_splice 313
>>>>> ./platforms/android-14/arch-x86/usr/include/asm/unistd_32.h:#define
>>>>> __NR_splice 313
>>>>>
>>>>> bionic:
>>>>> grep -r __NR_splice bionic
>>>>> bionic/libc/kernel/arch-sh/asm/unistd_32.h:#define __NR_splice 313
>>>>> bionic/libc/kernel/arch-sh/asm/unistd_64.h:#define __NR_splice 341
>>>>> bionic/libc/kernel/arch-x86/asm/unistd_32.h:#define __NR_splice 313
>>>>>
>>>>> Looking through results I see that '__NR_splice' it not in unistd.h
>>>>> and I know this is important.
>>>>>
>>>>> Ionut
>>>>>
>>>>>
>>>>> On Tue, May 21, 2013 at 5:15 PM, Pierre-Luc St-Charles <
>>>>> pierre-luc.st-charles at polymtl.ca> wrote:
>>>>>
>>>>>> The first error refers to __NR_splice, which should be declared once
>>>>>> asm/unistd.h is included; in this case, it is included right above the
>>>>>> problematic line (src/common/compat/fcntl.h @ L35). Could you verify that
>>>>>> __NR_splice is defined somewhere in that file? If not, it might be a little
>>>>>> more problematic.
>>>>>>
>>>>>> As for the second error, I believe it is also caused by a missing
>>>>>> symbol that should be included in asm/signal.h, which is in turn usually
>>>>>> included via signal.h itself.
>>>>>>
>>>>>> Compiling with the NDK (v8, platform 14) is successful here, and I
>>>>>> can find all these missing symbols in the default system includes there.
>>>>>> Are you sure you specified the target sysroot when compiling?
>>>>>>
>>>>>> -PL
>>>>>>
>>>>>>
>>>>>> On Tue, May 21, 2013 at 6:26 AM, Ionut D. <ionut5001 at gmail.com>wrote:
>>>>>>
>>>>>>> I tried to compile lttng-tools and at compile time exits with the
>>>>>>> bellow error. I looked in the sources and it looks like for arm this is not
>>>>>>> implemented. Do you have any idea about how could this be fixed?
>>>>>>>
>>>>>>>
>>>>>>> In file included from
>>>>>>> external/lttng-tools/src/common/compat/compat-fcntl.c:19:
>>>>>>> external/lttng-tools/src/common/compat/../../../src/common/compat/fcntl.h:
>>>>>>> In function 'splice':
>>>>>>> external/lttng-tools/src/common/compat/../../../src/common/compat/fcntl.h:44:
>>>>>>> error: '__NR_splice' undeclared (first use in this function)
>>>>>>> external/lttng-tools/src/common/compat/../../../src/common/compat/fcntl.h:44:
>>>>>>> error: (Each undeclared identifier is reported only once
>>>>>>> external/lttng-tools/src/common/compat/../../../src/common/compat/fcntl.h:44:
>>>>>>> error: for each function it appears in.)
>>>>>>> In file included from
>>>>>>> external/lttng-tools/src/common/compat/compat-fcntl.c:19:
>>>>>>> external/lttng-tools/src/common/compat/../../../src/common/compat/fcntl.h:48:1:
>>>>>>> warning: "POSIX_FADV_DONTNEED" redefined
>>>>>>> In file included from
>>>>>>> external/lttng-tools/src/common/compat/../../../src/common/compat/fcntl.h:47,
>>>>>>>                  from
>>>>>>> external/lttng-tools/src/common/compat/compat-fcntl.c:19:
>>>>>>> bionic/libc/kernel/common/linux/fadvise.h:24:1: warning: this is the
>>>>>>> location of the previous definition
>>>>>>> In file included from bionic/libc/include/sys/select.h:34,
>>>>>>>                  from bionic/libc/include/unistd.h:34,
>>>>>>>                  from
>>>>>>> external/lttng-tools/src/common/compat/compat-fcntl.c:20:
>>>>>>> external/lttng-tools/src/common/compat/signal.h: At top level:
>>>>>>> external/lttng-tools/src/common/compat/signal.h:27: error: expected
>>>>>>> ';', ',' or ')' before '*' token
>>>>>>> external/lttng-tools/src/common/compat/signal.h:28: error: expected
>>>>>>> ';', ',' or ')' before '*' token
>>>>>>> external/lttng-tools/src/common/compat/signal.h:29: error: expected
>>>>>>> ';', ',' or ')' before '*' token
>>>>>>> In file included from bionic/libc/include/unistd.h:34,
>>>>>>>                  from
>>>>>>> external/lttng-tools/src/common/compat/compat-fcntl.c:20:
>>>>>>> bionic/libc/include/sys/select.h:42: error: expected ';', ',' or ')'
>>>>>>> before '*' token
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> On Sat, May 18, 2013 at 10:21 AM, Ionut D. <ionut5001 at gmail.com>wrote:
>>>>>>>
>>>>>>>> Great informations! I will post back the results.
>>>>>>>>
>>>>>>>>
>>>>>>>> On Fri, May 17, 2013 at 4:47 PM, Pierre-Luc St-Charles <
>>>>>>>> pierre-luc.st-charles at polymtl.ca> wrote:
>>>>>>>>
>>>>>>>>> Alright, small update for all following a quick (non-mailing-list)
>>>>>>>>> exchange:
>>>>>>>>>
>>>>>>>>> We did successfully complete a kernel-tracing port of LTTng for
>>>>>>>>> Android (somewhat old news), but we are still working on bringing our
>>>>>>>>> patches back up to date with the current version of the different projects
>>>>>>>>> (soon-ish still applies here, we're talking days). So far, we dwelled a
>>>>>>>>> little bit in LTTng-UST, but haven't done much changes, so userspace
>>>>>>>>> tracing is still not functional. Device that ran kernel traces successfully
>>>>>>>>> so far were the Nexus S and the Nexus 7 (example Nexus S trace available
>>>>>>>>> here<https://drive.google.com/folderview?id=0B55Ba7lWTLh4U0hGeTQ4bmRYRjQ&usp=sharing>;
>>>>>>>>> still not perfect).
>>>>>>>>>
>>>>>>>>> Basically, we cross-compiled everything via the Android NDK (no
>>>>>>>>> Android makefiles involved here), and pushed all required bins to a device
>>>>>>>>> without having to flash it (unless the default kernel config didn't allow
>>>>>>>>> tracing -- then we'd have to flash). This approach is not compatible with
>>>>>>>>> the official Android build system (meaning we wouldn't be able to add it to
>>>>>>>>> Android like this), but we might eventually get working on the damned
>>>>>>>>> Android makefiles (they're extremely painful to write, especially since
>>>>>>>>> LTTng uses Autotools).
>>>>>>>>>
>>>>>>>>> The librairies required by LTTng that are not already included in
>>>>>>>>> a regular Android build (uuid/popt) can actually be found/compiled from the
>>>>>>>>> official repo, in its 'external' directory (see oprofile and e2fsprog --
>>>>>>>>> from memory). That might not be the easiest way to get them (full repo
>>>>>>>>> download is BIG), but compatibility is assured, and you can skip a full
>>>>>>>>> build by simply making those two individually for your device (if that's
>>>>>>>>> all you need).
>>>>>>>>>
>>>>>>>>> You'll also need your device to be rooted to use LTTng at all;
>>>>>>>>> then, most initializations are done via scripts (we'll also provide those
>>>>>>>>> with our patches). We still had some trouble automating everything via
>>>>>>>>> daemons, so we always ran the sessiond locally (with success).
>>>>>>>>>
>>>>>>>>> Major problems we encountered so far were missing posix functions,
>>>>>>>>> and sysv shared memory. Basically, Android relies on Bionic for its system
>>>>>>>>> calls and other low-level functions, and since Bionic is pretty
>>>>>>>>> 'lightweight', they trimmed most of the fat out for performance. We had to
>>>>>>>>> make some more-or-less sketchy replacements here and there, but everything
>>>>>>>>> seems to be working decently now.
>>>>>>>>>
>>>>>>>>> So, simple 'how do I put LTTng on Android' workflow would be this:
>>>>>>>>>
>>>>>>>>>   - Compile modules (using NDK) against device's kernel, making
>>>>>>>>> sure its config is appropriate, ship them over via ADB
>>>>>>>>>
>>>>>>>>>   - Compile required external libraries (using repo build system)
>>>>>>>>> for the device, ship them over via ADB
>>>>>>>>>
>>>>>>>>>   - Patch up LTTng-* (soon-ish! I could send you the outdated
>>>>>>>>> patches right now if you're interested though, they might be a month behind
>>>>>>>>> or so on the current trunks)
>>>>>>>>>
>>>>>>>>>   - Cross-compile LTTng-* for the device (using NDK), ship
>>>>>>>>> binaries over via ADB
>>>>>>>>>
>>>>>>>>> Then, on the device, start up the sessiond manually & start
>>>>>>>>> tracing.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I think I went over everything, but if there's a part that's still
>>>>>>>>> cloudy, don't hesitate.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> -PL
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On May 17, 2013 1:32 AM, "Ionut D." <ionut5001 at gmail.com> wrote:
>>>>>>>>>
>>>>>>>>>> Hello all,
>>>>>>>>>>
>>>>>>>>>> Recently I started to integrate LTTNG in Android ICS by compiling
>>>>>>>>>> each package, each dependency, by using the Android build system. It is a
>>>>>>>>>> lot of work because I met different problems and to be sincere, I do not
>>>>>>>>>> know if at the end will work and I do not know how much I will need to
>>>>>>>>>> modify the sources in order to work.
>>>>>>>>>>
>>>>>>>>>> My questions are about this integration. I mention that I read a
>>>>>>>>>> lot of discussions about this on Internet, on this mailing list, but the
>>>>>>>>>> things are still not very clear for me.
>>>>>>>>>>
>>>>>>>>>> It is ok? what I am trying to do ? to integrate and build by
>>>>>>>>>> using the Android build system.
>>>>>>>>>> Could you give me some guidelines, indications about how I should
>>>>>>>>>> proceed, maybe a tutorial or maybe some android make files/patches that
>>>>>>>>>> would help me to see how the job must be done and if I am doing it right ?
>>>>>>>>>>
>>>>>>>>>> Until now I managed to build lttng-modules, liburcu, libuuid from
>>>>>>>>>> util-linux and configure lttng-ust by using the android toolchain for arm.
>>>>>>>>>> I got a lot of errors but until now I managed to configure/make these
>>>>>>>>>> packages.
>>>>>>>>>>
>>>>>>>>>> I mention that I am trying to build lttng 2.x on ICS 4.0.3.
>>>>>>>>>>
>>>>>>>>>> Would be great if you will give me a tutorial about how to do it.
>>>>>>>>>>
>>>>>>>>>> Ionut
>>>>>>>>>>
>>>>>>>>>> _______________________________________________
>>>>>>>>>> lttng-dev mailing list
>>>>>>>>>> lttng-dev at lists.lttng.org
>>>>>>>>>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
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>
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