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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2018-12-06 11:52:20 +0300 |
|---|---|---|
| committer | Minda Chen <minda.chen@starfivetech.com> | 2023-11-06 14:24:48 +0300 |
| commit | 21d7bdc560685efe4b6d35c81d209719bf38a2d3 (patch) | |
| tree | ddcdd0aa3017ebe92459d7c2e8d929fe5f3d40a1 | |
| parent | 1582d433a4208dcb37a673263049f3dc240332e6 (diff) | |
| download | linux-21d7bdc560685efe4b6d35c81d209719bf38a2d3.tar.xz | |
drm/i915: Disable tracing points on PREEMPT_RT
Luca Abeni reported this:
| BUG: scheduling while atomic: kworker/u8:2/15203/0x00000003
| CPU: 1 PID: 15203 Comm: kworker/u8:2 Not tainted 4.19.1-rt3 #10
| Call Trace:
| rt_spin_lock+0x3f/0x50
| gen6_read32+0x45/0x1d0 [i915]
| g4x_get_vblank_counter+0x36/0x40 [i915]
| trace_event_raw_event_i915_pipe_update_start+0x7d/0xf0 [i915]
The tracing events use trace_i915_pipe_update_start() among other events
use functions acquire spinlock_t locks which are transformed into
sleeping locks on PREEMPT_RT. A few trace points use
intel_get_crtc_scanline(), others use ->get_vblank_counter() wich also
might acquire a sleeping locks on PREEMPT_RT.
At the time the arguments are evaluated within trace point, preemption
is disabled and so the locks must not be acquired on PREEMPT_RT.
Based on this I don't see any other way than disable trace points on
PREMPT_RT.
Reported-by: Luca Abeni <lucabe72@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
| -rw-r--r-- | drivers/gpu/drm/i915/i915_trace.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h index 63fec1c3c132..0cddc5bb0ebe 100644 --- a/drivers/gpu/drm/i915/i915_trace.h +++ b/drivers/gpu/drm/i915/i915_trace.h @@ -2,6 +2,10 @@ #if !defined(_I915_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ) #define _I915_TRACE_H_ +#ifdef CONFIG_PREEMPT_RT +#define NOTRACE +#endif + #include <linux/stringify.h> #include <linux/types.h> #include <linux/tracepoint.h> |