2008-08-27 00:27:41

by Peter Teoh

[permalink] [raw]
Subject: Locking API testsuite: Failures

[ 0.000999] | Locking API testsuite:
[ 0.000999] ----------------------------------------------------------------------------
[ 0.000999] | spin |wlock |rlock
|mutex | wsem | rsem |
[ 0.000999]
--------------------------------------------------------------------------
[ 0.000999] A-A deadlock:failed|failed| ok
|failed|failed|failed|
[ 0.000999] A-B-B-A deadlock:failed|failed| ok
|failed|failed|failed|
[ 0.000999] A-B-B-C-C-A deadlock:failed|failed| ok
|failed|failed|failed|
[ 0.000999] A-B-C-A-B-C deadlock:failed|failed| ok
|failed|failed|failed|
[ 0.000999] A-B-B-C-C-D-D-A deadlock:failed|failed| ok
|failed|failed|failed|
[ 0.000999] A-B-C-D-B-D-D-A deadlock:failed|failed| ok
|failed|failed|failed|
[ 0.000999] A-B-C-D-B-C-D-A deadlock:failed|failed| ok
|failed|failed|failed|
[ 0.000999] double
unlock:failed|failed|failed|failed|failed|failed|
[ 0.000999] initialize
held:failed|failed|failed|failed|failed|failed|
[ 0.000999] bad unlock order: ok | ok | ok |
ok | ok | ok |
[ 0.000999]
--------------------------------------------------------------------------
[ 0.000999] recursive read-lock: | ok |
|failed|
[ 0.000999] recursive read-lock #2: | ok |
|failed|
[ 0.000999] mixed read-write-lock: |failed|
|failed|
[ 0.000999] mixed write-read-lock: |failed|
|failed|
[ 0.000999]
--------------------------------------------------------------------------
[ 0.000999] hard-irqs-on + irq-safe-A/12:failed|failed| ok |
[ 0.000999] soft-irqs-on + irq-safe-A/12:failed|failed| ok |
[ 0.000999] hard-irqs-on + irq-safe-A/21:failed|failed| ok |
[ 0.000999] soft-irqs-on + irq-safe-A/21:failed|failed| ok |
[ 0.000999] sirq-safe-A => hirqs-on/12:failed|failed| ok |
[ 0.000999] sirq-safe-A => hirqs-on/21:failed|failed| ok |
[ 0.000999] hard-safe-A + irqs-on/12:failed|failed| ok |
[ 0.000999] soft-safe-A + irqs-on/12:failed|failed| ok |
[ 0.000999] hard-safe-A + irqs-on/21:failed|failed| ok |
[ 0.000999] soft-safe-A + irqs-on/21:failed|failed| ok |
[ 0.000999] hard-safe-A + unsafe-B #1/123:failed|failed| ok |
[ 0.000999] soft-safe-A + unsafe-B #1/123:failed|failed| ok |

truncated....

I am just curious what does all these failures imply?

thanks.

--
Regards,
Peter Teoh


2008-08-27 01:58:41

by Peter Zijlstra

[permalink] [raw]
Subject: Re: Locking API testsuite: Failures

On Wed, 2008-08-27 at 08:27 +0800, Peter Teoh wrote:
> [ 0.000999] | Locking API testsuite:
> [ 0.000999] ----------------------------------------------------------------------------
> [ 0.000999] | spin |wlock |rlock
> |mutex | wsem | rsem |
> [ 0.000999]
> --------------------------------------------------------------------------
> [ 0.000999] A-A deadlock:failed|failed| ok
> |failed|failed|failed|
> [ 0.000999] A-B-B-A deadlock:failed|failed| ok
> |failed|failed|failed|
> [ 0.000999] A-B-B-C-C-A deadlock:failed|failed| ok
> |failed|failed|failed|
> [ 0.000999] A-B-C-A-B-C deadlock:failed|failed| ok
> |failed|failed|failed|
> [ 0.000999] A-B-B-C-C-D-D-A deadlock:failed|failed| ok
> |failed|failed|failed|
> [ 0.000999] A-B-C-D-B-D-D-A deadlock:failed|failed| ok
> |failed|failed|failed|
> [ 0.000999] A-B-C-D-B-C-D-A deadlock:failed|failed| ok
> |failed|failed|failed|
> [ 0.000999] double
> unlock:failed|failed|failed|failed|failed|failed|
> [ 0.000999] initialize
> held:failed|failed|failed|failed|failed|failed|
> [ 0.000999] bad unlock order: ok | ok | ok |
> ok | ok | ok |
> [ 0.000999]
> --------------------------------------------------------------------------
> [ 0.000999] recursive read-lock: | ok |
> |failed|
> [ 0.000999] recursive read-lock #2: | ok |
> |failed|
> [ 0.000999] mixed read-write-lock: |failed|
> |failed|
> [ 0.000999] mixed write-read-lock: |failed|
> |failed|
> [ 0.000999]
> --------------------------------------------------------------------------
> [ 0.000999] hard-irqs-on + irq-safe-A/12:failed|failed| ok |
> [ 0.000999] soft-irqs-on + irq-safe-A/12:failed|failed| ok |
> [ 0.000999] hard-irqs-on + irq-safe-A/21:failed|failed| ok |
> [ 0.000999] soft-irqs-on + irq-safe-A/21:failed|failed| ok |
> [ 0.000999] sirq-safe-A => hirqs-on/12:failed|failed| ok |
> [ 0.000999] sirq-safe-A => hirqs-on/21:failed|failed| ok |
> [ 0.000999] hard-safe-A + irqs-on/12:failed|failed| ok |
> [ 0.000999] soft-safe-A + irqs-on/12:failed|failed| ok |
> [ 0.000999] hard-safe-A + irqs-on/21:failed|failed| ok |
> [ 0.000999] soft-safe-A + irqs-on/21:failed|failed| ok |
> [ 0.000999] hard-safe-A + unsafe-B #1/123:failed|failed| ok |
> [ 0.000999] soft-safe-A + unsafe-B #1/123:failed|failed| ok |
>
> truncated....
>
> I am just curious what does all these failures imply?

Probably that you forgot to enable lockdep ;-)

In which case the error cases fail to produce an error, and the test
fails, but its an expected error, otherwise it would have shouted much
more verbose.


2008-08-27 06:32:21

by Peter Teoh

[permalink] [raw]
Subject: Re: Locking API testsuite: Failures

Thanks for the reply.

On Wed, Aug 27, 2008 at 9:58 AM, Peter Zijlstra <[email protected]> wrote:
> On Wed, 2008-08-27 at 08:27 +0800, Peter Teoh wrote:
>> [ 0.000999] | Locking API testsuite:
>> [ 0.000999] ----------------------------------------------------------------------------
>> [ 0.000999] | spin |wlock |rlock
>> |mutex | wsem | rsem |
>> [ 0.000999]
>> --------------------------------------------------------------------------
>> [ 0.000999] A-A deadlock:failed|failed| ok
>> |failed|failed|failed|
>> [ 0.000999] A-B-B-A deadlock:failed|failed| ok
>> |failed|failed|failed|
>> [ 0.000999] A-B-B-C-C-A deadlock:failed|failed| ok
>> |failed|failed|failed|
>> [ 0.000999] A-B-C-A-B-C deadlock:failed|failed| ok
>> |failed|failed|failed|
>> [ 0.000999] A-B-B-C-C-D-D-A deadlock:failed|failed| ok
>> |failed|failed|failed|
>> [ 0.000999] A-B-C-D-B-D-D-A deadlock:failed|failed| ok
>> |failed|failed|failed|
>> [ 0.000999] A-B-C-D-B-C-D-A deadlock:failed|failed| ok
>> |failed|failed|failed|
>> [ 0.000999] double
>> unlock:failed|failed|failed|failed|failed|failed|
>> [ 0.000999] initialize
>> held:failed|failed|failed|failed|failed|failed|
>> [ 0.000999] bad unlock order: ok | ok | ok |
>> ok | ok | ok |
>> [ 0.000999]
>> --------------------------------------------------------------------------
>> [ 0.000999] recursive read-lock: | ok |
>> |failed|
>> [ 0.000999] recursive read-lock #2: | ok |
>> |failed|
>> [ 0.000999] mixed read-write-lock: |failed|
>> |failed|
>> [ 0.000999] mixed write-read-lock: |failed|
>> |failed|
>> [ 0.000999]
>> --------------------------------------------------------------------------
>> [ 0.000999] hard-irqs-on + irq-safe-A/12:failed|failed| ok |
>> [ 0.000999] soft-irqs-on + irq-safe-A/12:failed|failed| ok |
>> [ 0.000999] hard-irqs-on + irq-safe-A/21:failed|failed| ok |
>> [ 0.000999] soft-irqs-on + irq-safe-A/21:failed|failed| ok |
>> [ 0.000999] sirq-safe-A => hirqs-on/12:failed|failed| ok |
>> [ 0.000999] sirq-safe-A => hirqs-on/21:failed|failed| ok |
>> [ 0.000999] hard-safe-A + irqs-on/12:failed|failed| ok |
>> [ 0.000999] soft-safe-A + irqs-on/12:failed|failed| ok |
>> [ 0.000999] hard-safe-A + irqs-on/21:failed|failed| ok |
>> [ 0.000999] soft-safe-A + irqs-on/21:failed|failed| ok |
>> [ 0.000999] hard-safe-A + unsafe-B #1/123:failed|failed| ok |
>> [ 0.000999] soft-safe-A + unsafe-B #1/123:failed|failed| ok |
>>
>> truncated....
>>
>> I am just curious what does all these failures imply?
>
> Probably that you forgot to enable lockdep ;-)
>

Several questions:

1. I noticed there is a Kconfig.debug with this entry:

config DEBUG_LOCKING_API_SELFTESTS
bool "Locking API boot-time self-tests"
depends on DEBUG_KERNEL
help
Say Y here if you want the kernel to run a short self-test during
bootup. The self-test checks whether common types of locking bugs
are detected by debugging mechanisms or not. (if you disable
lock debugging then those bugs wont be detected of course.)
The following locking APIs are covered: spinlocks, rwlocks,
mutexes and rwsems.

How do I use this Kconfig.debug, just overwriting the standard
lib/Kconfig? I overwrote it and got the following errors:

scripts/kconfig/conf -o arch/x86/Kconfig
file kernel/trace/Kconfig already scanned?
make[1]: *** [oldconfig] Error 1
make: *** [oldconfig] Error 2

2. So does it make sense to compile with
CONFIG_DEBUG_LOCKING_API_SELFTESTS without CONFIG_LOCKDEP?
Should the lib/Kconfig indicate such a dependency?

3. My current .config (which gave rise to the failure errors) has
CONFIG_LOCKDEP_SUPPORT=y, and CONFIG_DEBUG_LOCKING_API_SELFTESTS=y.
Question is what is the different between LOCKDEP_SUPPORT and LOCKDEP
alone?

Thanks.

> In which case the error cases fail to produce an error, and the test
> fails, but its an expected error, otherwise it would have shouted much
> more verbose.
>
>
>
>



--
Regards,
Peter Teoh

2008-08-27 06:46:17

by Ingo Molnar

[permalink] [raw]
Subject: Re: Locking API testsuite: Failures


* Peter Teoh <[email protected]> wrote:

> Several questions:

[...]
> 3. My current .config (which gave rise to the failure errors) [...]

You should have read this bit of the self-test printout:

[ 0.004000] 133 out of 218 testcases failed, as expected. |

there was no unexpected failure. A real test-case failure is displayed
as: 'FAILED', and you'll get a verbose printout about the unexpected
testcase failures.

> 1. I noticed there is a Kconfig.debug with this entry:
>
> config DEBUG_LOCKING_API_SELFTESTS
> bool "Locking API boot-time self-tests"
> depends on DEBUG_KERNEL
> help
> Say Y here if you want the kernel to run a short self-test during
> bootup. The self-test checks whether common types of locking bugs
> are detected by debugging mechanisms or not. (if you disable
> lock debugging then those bugs wont be detected of course.)
> The following locking APIs are covered: spinlocks, rwlocks,
> mutexes and rwsems.
>
> How do I use this Kconfig.debug, just overwriting the standard
> lib/Kconfig? [...]

no, that messes up the kernel. Kconfig.debug is a separate, unique
kconfig file with debugging related options.

> 2. So does it make sense to compile with
> CONFIG_DEBUG_LOCKING_API_SELFTESTS without CONFIG_LOCKDEP?

yes. It shows the kinds of bugs we dont find when PROVE_LOCKING is
disabled. It also shows that the test-cases are working as expected.

Ingo