From patchwork Thu Aug 2 20:48:44 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ezequiel Garcia X-Patchwork-Id: 10554217 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BF12313B4 for ; Thu, 2 Aug 2018 20:49:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AB9B82BDFA for ; Thu, 2 Aug 2018 20:49:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9FD662BE04; Thu, 2 Aug 2018 20:49:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 265882BDFC for ; Thu, 2 Aug 2018 20:49:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730951AbeHBWlt (ORCPT ); Thu, 2 Aug 2018 18:41:49 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:50296 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729763AbeHBWlt (ORCPT ); Thu, 2 Aug 2018 18:41:49 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id 812BD261486 From: Ezequiel Garcia To: linux-media@vger.kernel.org Cc: Hans Verkuil , kernel@collabora.com, paul.kocialkowski@bootlin.com, maxime.ripard@bootlin.com, Hans Verkuil , Shuah Khan , linux-kselftest@vger.kernel.org, Ezequiel Garcia Subject: [PATCH v4 0/6] Make sure .device_run is always called in non-atomic context Date: Thu, 2 Aug 2018 17:48:44 -0300 Message-Id: <20180802204850.31633-1-ezequiel@collabora.com> X-Mailer: git-send-email 2.18.0 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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