[lttng-dev] LTTNG on Android ICS

Pierre-Luc St-Charles pierre-luc.st-charles at polymtl.ca
Tue May 21 14:26:34 EDT 2013


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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