Hi Hans,
On 2 August 2018 at 17:48, Ezequiel Garcia wrote:
> v4:
> * Add patches and 1 and 2, to make q_lock mandatory,
> in other words, require output and capture locks to match.
> * Add WARN_ON if the lock is not held in v4l2_m2m_try_schedule,
> and also document the requirement.
> * Add a comment explaining why the job is scheduled.
>
> This series goal is to avoid drivers from having ad-hoc code
> to call .device_run in non-atomic context. Currently, .device_run
> can be called via v4l2_m2m_job_finish(), potentially running
> in interrupt context.
>
> This series will be useful for the upcoming Request API, where drivers
> typically require .device_run to be called in non-atomic context for
> v4l2_ctrl_request_setup() calls.
>
> The solution is to add a per-device worker that is scheduled
> by v4l2_m2m_job_finish, which replaces drivers having a threaded interrupt
> or similar.
>
> This change allows v4l2_m2m_job_finish() to be called in interrupt
> context, separating .device_run and v4l2_m2m_job_finish() contexts.
>
> It's worth mentioning that v4l2_m2m_cancel_job() doesn't need
> to flush or cancel the new worker, because the job_spinlock
> synchronizes both and also because the core prevents simultaneous
> jobs. Either v4l2_m2m_cancel_job() will wait for the worker, or the
> worker will be unable to run a new job.
>
> Testing
> ---
>
> In order to test the change, and make sure no regressions are
> introduced, a kselftest test is added to stress the mem2mem framework.
>
> Note that this series rework the kselftest media_tests target.
> Those tests that need hardware and human intervention are now
> marked as _EXTENDED, and a frontend script is added to run those
> tests that can run without hardware or human intervention.
>
> This will allow the media_tests target to be included in
> automatic regression testing setups.
>
> Hopefully, we will be able to introduce more and more automatic
> regression tests. Currently, our self-test run looks like:
>
> $ make TARGETS=media_tests kselftest
> make[1]: Entering directory '/home/zeta/repos/builds/virtme-x86_64'
> make[3]: warning: jobserver unavailable: using -j1. Add '+' to parent
> make rule.
> make[3]: Nothing to be done for 'all'.
> make[3]: warning: jobserver unavailable: using -j1. Add '+' to parent
> make rule.
> TAP version 13
> selftests: media_tests: m2m_job_test.sh
>
> ---
> running media tests
> ---
> media_device : no video4linux drivers loaded, vim2m is needed
> not ok 1..1 selftests: media_tests: m2m_job_test.sh [SKIP]
> make[1]: Leaving directory '/home/zeta/repos/builds/virtme-x86_64'
>
> Ezequiel Garcia (5):
> mem2mem: Require capture and output mutexes to match
> v4l2-ioctl.c: simplify locking for m2m devices
> v4l2-mem2mem: Avoid v4l2_m2m_prepare_buf from scheduling a job
> v4l2-mem2mem: Avoid calling .device_run in v4l2_m2m_job_finish
> selftests: media_tests: Add a memory-to-memory concurrent stress test
>
> Sakari Ailus (1):
> v4l2-mem2mem: Simplify exiting the function in __v4l2_m2m_try_schedule
>
> drivers/media/v4l2-core/v4l2-ioctl.c | 47 +--
> drivers/media/v4l2-core/v4l2-mem2mem.c| 94 --
> .../testing/selftests/media_tests/.gitignore | 1 +
> tools/testing/selftests/media_tests/Makefile | 5 +-
> .../selftests/media_tests/m2m_job_test.c | 287 ++
> .../selftests/media_tests/m2m_job_test.sh | 32 ++
> 6 files changed, 389 insertions(+), 77 deletions(-)
> create mode 100644 tools/testing/selftests/media_tests/m2m_job_test.c
> create mode 100755 tools/testing/selftests/media_tests/m2m_job_test.sh
>
> --
> 2.18.0
>
I am going to send a v5 soon, addressing Guillaume's comments.
Any feedback on media side?
Thanks,
--
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar
