On 18 May 2012 08:39, Jon Medhurst (Tixy) tixy@linaro.org wrote:

On Thu, 2012-05-17 at 18:25 +0100, Jon Medhurst (Tixy) wrote:

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On Thu, 2012-05-17 at 23:51 +0800, Andy Green wrote:

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On 17/05/12 23:46, Somebody in the thread at some point said:

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On 17 May 2012 11:44, David Longdave.long@linaro.org  wrote:

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On Thu, 2012-05-17 at 10:36 -0500, Zach Pfeffer wrote:

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We're getting an error when we build our tip Panda build:

1 /mnt/jenkins/workspace/linaro-android_panda-ics-gcc47-tilt-tracking-blob/build/external/gator/driver/gator_main.c:51:2: error: #error gator requires the kernel to have CONFIG_PERF_EVENTS defined to support pmu hardware counters

2 make[3]: *** [/mnt/jenkins/workspace/linaro-android_panda-ics-gcc47-tilt-tracking-blob/build/external/gator/driver/gator_main.o] Error 1

3 make[2]: *** [_module_/mnt/jenkins/workspace/linaro-android_panda-ics-gcc47-tilt-tracking-blob/build/external/gator/driver] Error 2

4 make[1]: *** [sub-make] Error 2

5 make: *** [gator_driver] Error 2

We turned this off in part to avoid errata in the core for which we have no workaround.  The kernel and perf tools should fall back to just using time in this case, and work more reliably.  I don't know what gator is or why it demands hardware counters, but turning this kernel option back on is quite undesirable.

Gator is a plugin used by ARM's DS-5 debugging and profiling tool. We need it and it should have been on for previous months so it is nothing new.

Hm.  If Dave is right - and this was his business for six months or so - that we turned off CONFIG_PERF_EVENTS because of "errata in the core for which we have no workaround", then I would ask Anmar which config option we should enable "because it's nothing new".

What is new is that the latest Gator code does an #error rather than #warning when perf events aren't enabled. I've contacted the main author of gator for advice and I will do some investigation myself.

If perf events turn out to be mandatory, then the only thing is to remove Gator from Panda build. If they aren't, I can revert the #error back to #warning. (There may be a middle way of modifying Gator to not mandate perf events.)

I will come up with a solution one way or another before this time tomorrow.

I have changed the #error lines back to #warning, this produces a Gator component with reduced functionality but it builds and works when perf events aren't configured in the kernel.

I rebuilt and tested Panda Android [1] and my topic branches have been updated with the change. Any kernels with problems should pull the topic branch again.

Thanks Tixy.

Andrey, can you refresh linux-linaro-core-tracking ?

Thanks

-- Tixy

[1] https://android-build.linaro.org/builds/~linaro-android/panda-ics-gcc47-tilt...