2014-02-14 09:02:57

by Naresh Kamboju

[permalink] [raw]
Subject: How to get the Linux kernel coverage data on ARM arch when I run LTP test?

Hi All,

Sorry for the wide distribution:

According to LTP page info,
http://ltp.sourceforge.net/coverage/gcov.php
http://ltp.sourceforge.net/coverage/lcov.php

My question is
How to get kernel coverage when I run LTP test?

Since we do not have direct GCOV support on ARM I have enabled ( just
for experiment)

$ git diff kernel/gcov/Kconfig
diff --git a/kernel/gcov/Kconfig b/kernel/gcov/Kconfig
index d4da55d..fceac85 100644
--- a/kernel/gcov/Kconfig
+++ b/kernel/gcov/Kconfig
@@ -35,7 +35,7 @@ config GCOV_KERNEL
config GCOV_PROFILE_ALL
bool "Profile entire Kernel"
depends on GCOV_KERNEL
- depends on SUPERH || S390 || X86 || PPC || MICROBLAZE
+ depends on SUPERH || S390 || X86 || PPC || MICROBLAZE || ARM
default n
---help---
This options activates profiling for the entire kernel.

I have enabled below kernel config and built the kernel.
CONFIG_GCOV_KERNEL=y
CONFIG_GCOV_PROFILE_ALL=y
CONFIG_GCOV_FORMAT_AUTODETECT=y

of course I have disabled gcov on below folders and files, because
since it is an experiment i would like to be on safe side
- arch/arm/mm/
- arch/arm/kernel/
- arch/arm/boot/
- arch/arm/boot/compressed/
- arch/arm/boot/bootp/
- arch/arm/boot/dts

Arndale booted with this configuration successfully.
Took more than 65 seconds to finish boot.

gcov related files are found under /sys/ similer to X86 machine.
And gcov supporting files filename.gcda are having links to kernel source
root@linaro-developer:~# ls /sys/kernel/debug/gcov/
reset tmp
root@linaro-developer:~#

root@linaro-developer:~# ls /sys/kernel/debug/gcov/tmp/
linux-linaro-3.13-2014.01
root@linaro-developer:~# ls
/sys/kernel/debug/gcov/tmp/linux-linaro-3.13-2014.01/
arch block crypto drivers fs init ipc kernel lib mm security virt
root@linaro-developer:~# ls
/sys/kernel/debug/gcov/tmp/linux-linaro-3.13-2014.01/kernel/time.* -l
-rw------- 1 root root 0 Jan 1 1970
/sys/kernel/debug/gcov/tmp/linux-linaro-3.13-2014.01/kernel/time.gcda
lrwxrwxrwx 1 root root 0 Jan 1 1970
/sys/kernel/debug/gcov/tmp/linux-linaro-3.13-2014.01/kernel/time.gcno
-> /tmp/linux-linaro-3.13-2014.01/kernel/time.gcno
root@linaro-developer:~#

Source are placed under /tmp/
root@linaro-developer:/tmp/linux-linaro-3.13-2014.01# ls kernel/time.* -l
-rw-rw-r-- 1 linaro linaro 19233 Jan 24 2014 kernel/time.c
-rw-rw-r-- 1 linaro linaro 12768 Feb 13 2014 kernel/time.gcno
-rw-rw-r-- 1 linaro linaro 136444 Feb 13 2014 kernel/time.o
root@linaro-developer:/tmp/linux-linaro-3.13-2014.01#


root@linaro-developer:/tmp/linux-linaro-3.13-2014.01# gcov kernel/gcov/base.c -o
/sys/kernel/debug/gcov/tmp/linux-linaro-3.13-2014.01/kernel/gcov/
File 'kernel/gcov/base.c'
Lines executed:43.18% of 44
Creating 'base.c.gcov'

root@linaro-developer:/tmp/linux-linaro-3.13-2014.01#

The above experiment gives coverage of a single file base.c when i run
gcov manually.
Is there any way to get Linux kernel coverage of all files after
running LTP test cases ?

Thanks in advance.

Best regards
Naresh Kamboju


2014-02-14 09:43:08

by Peter Oberparleiter

[permalink] [raw]
Subject: Re: [LTP] How to get the Linux kernel coverage data on ARM arch when I run LTP test?

On 14.02.2014 10:02, Naresh Kamboju wrote:
> root@linaro-developer:/tmp/linux-linaro-3.13-2014.01# gcov kernel/gcov/base.c -o
> /sys/kernel/debug/gcov/tmp/linux-linaro-3.13-2014.01/kernel/gcov/
> File 'kernel/gcov/base.c'
> Lines executed:43.18% of 44
> Creating 'base.c.gcov'
>
> root@linaro-developer:/tmp/linux-linaro-3.13-2014.01#
>
> The above experiment gives coverage of a single file base.c when i run
> gcov manually.
> Is there any way to get Linux kernel coverage of all files after
> running LTP test cases ?

1. Reset coverage data: lcov -z
2. Run LTP (or any other test case)
3. Capture coverage data: lcov -c -o coverage.info
4. Generate HTML output: genhtml coverage.info -o out
5. View HTML output: <browser> out/index.html

More information on lcov can be found on the page behind the second URL
your quoted in your mail.


Regards,
Peter Oberparleiter

--
Peter Oberparleiter
Linux on System z Development - IBM Germany

2014-02-18 14:30:29

by Naresh Kamboju

[permalink] [raw]
Subject: Re: [LTP] How to get the Linux kernel coverage data on ARM arch when I run LTP test?

On 14 February 2014 15:13, Peter Oberparleiter
<[email protected]> wrote:
> On 14.02.2014 10:02, Naresh Kamboju wrote:
>> root@linaro-developer:/tmp/linux-linaro-3.13-2014.01# gcov kernel/gcov/base.c -o
>> /sys/kernel/debug/gcov/tmp/linux-linaro-3.13-2014.01/kernel/gcov/
>> File 'kernel/gcov/base.c'
>> Lines executed:43.18% of 44
>> Creating 'base.c.gcov'
>>
>> root@linaro-developer:/tmp/linux-linaro-3.13-2014.01#
>>
>> The above experiment gives coverage of a single file base.c when i run
>> gcov manually.
>> Is there any way to get Linux kernel coverage of all files after
>> running LTP test cases ?
>
> 1. Reset coverage data: lcov -z
> 2. Run LTP (or any other test case)
> 3. Capture coverage data: lcov -c -o coverage.info
> 4. Generate HTML output: genhtml coverage.info -o out
> 5. View HTML output: <browser> out/index.html

It is working !!!
LTP executed on linux-linaro build on vexpress-tc2 target.
Please find results obtained
http://people.linaro.org/~naresh.kamboju/linux-linaro-coverage-by-ltp/

The plan is to run all linaro test suite and to get coverage date.

Peter Oberparleiter,
Thank you very much for your help.

Best regards
Naresh Kamboju

>
> More information on lcov can be found on the page behind the second URL
> your quoted in your mail.
>
>
> Regards,
> Peter Oberparleiter
>
> --
> Peter Oberparleiter
> Linux on System z Development - IBM Germany
>