From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: [PATCH RFC tip/core/rcu 2/4] drivers/gpu/drm: Dynamically allocate drm_unplug_srcu Date: Tue, 2 Apr 2019 07:29:31 -0700 Message-ID: <20190402142933.14547-2-paulmck@linux.ibm.com> References: <20190402142816.GA13084@linux.ibm.com> Return-path: In-Reply-To: <20190402142816.GA13084@linux.ibm.com> Sender: linux-kernel-owner@vger.kernel.org To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" , Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , Tejun Heo , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org Having DEFINE_SRCU() or DEFINE_STATIC_SRCU() in a loadable module requires that the size of the reserved region be increased, which is not something we really want to be doing. This commit therefore removes the DEFINE_STATIC_SRCU() from drivers/gpu/drm/drm_drv.c in favor of defining drm_unplug_srcu as a simple srcu_struct, initializing it in drm_core_init(), and cleaning it up in drm_core_exit(). In this particular case, drm_unplug_srcu is statically allocated and thus guaranteed to be initially zero. Unfortunately, cleanup_srcu_struct() cannot rely on this in the general case (which includes dynamically allocated srcu_struct structures), and therefore cannot tell whether it is being called on something that has been passed to init_srcu_struct(). Thus the code added to drm_core_init() is a bit non-standard. Reported-by: kbuild test robot Signed-off-by: Paul E. McKenney Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Sean Paul Cc: David Airlie Cc: Daniel Vetter Cc: Tejun Heo Cc: --- drivers/gpu/drm/drm_drv.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 381581b01d48..ce4582af814d 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -77,7 +77,7 @@ static bool drm_core_init_complete = false; static struct dentry *drm_debugfs_root; -DEFINE_STATIC_SRCU(drm_unplug_srcu); +static struct srcu_struct drm_unplug_srcu; /* * DRM Minors @@ -958,12 +958,18 @@ static void drm_core_exit(void) drm_sysfs_destroy(); idr_destroy(&drm_minors_idr); drm_connector_ida_destroy(); + cleanup_srcu_struct(&drm_unplug_srcu); } static int __init drm_core_init(void) { int ret; + ret = init_srcu_struct(&drm_unplug_srcu); + if (ret) { + DRM_ERROR("Cannot create DRM class: %d\n", ret); + return ret; /* cannot cleanup after failed srcu_struct init. */ + } drm_connector_ida_init(); idr_init(&drm_minors_idr); -- 2.17.1