Tracepoints that display frame and scanline counters for all pipes were
added with commit 1489bba824 ("drm/i915: Add cxsr toggle tracepoint")
and commit 0b2599a43c ("drm/i915: Add pipe enable/disable
tracepoints"). At that time, we only had pipes A, B and C. Now that we
can also have pipe D, the TP_printk() calls are missing it.
As a quick and dirty fix for that, let's define two common macros to be
used for the format and values respectively, and also ensure we raise a
build bug if more pipes are added to enum pipe.
In the future, we should probably have a way of printing information for
available pipes only.
Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016135300.21428-6-gustavo.sousa@intel.com
The first part[1] of the LWN series on using TRACE_EVENT() mentions
about TP_printk():
"Do not create new tracepoint-specific helpers, because that will
confuse user-space tools that know about the TRACE_EVENT() helper
macros but will not know how to handle ones created for individual
tracepoints."
It seems this is what we ended up doing when using pipe_name() in
TP_printk().
For example, the format for the intel_pipe_update_start event is as
follows:
# cat /sys/kernel/debug/tracing/events/i915/intel_pipe_update_start/format
name: intel_pipe_update_start
ID: 1136
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:__data_loc char[] dev; offset:8; size:4; signed:0;
field:enum pipe pipe; offset:12; size:4; signed:1;
field:u32 frame; offset:16; size:4; signed:0;
field:u32 scanline; offset:20; size:4; signed:0;
field:u32 min; offset:24; size:4; signed:0;
field:u32 max; offset:28; size:4; signed:0;
print fmt: "dev %s, pipe %c, frame=%u, scanline=%u, min=%u, max=%u", __get_str(dev), ((REC->pipe) + 'A'), REC->frame, REC->scanline, REC->min, REC->max
The call to pipe_name(__entry->pipe) is expanted to ((REC->pipe) + 'A')
and that's how the format is saved.
Even though the output from /sys/kernel/debug/tracing/trace will look
correct (because it is generated in the kernel), we will see corrupted
lines when using a tool like trace-cmd to view the data.
While the output looks correct when looking at
/sys/kernel/debug/tracing/trace, we see corrupted lines when viewing the
trace data with "trace-cmd report":
$ trace-cmd report \
> | sed -n 's/.*dev 0000:00:02\.0, \(pipe .\).*/\1/p' \
> | cat -v | uniq -c
34 pipe ^A
, where ^A is a non-printable character.
As a fix, let's store the pipe name directly in the event. The fix was
done by applying the following sed script:
s/__field\s*(\s*enum\s\+pipe\s*,\s*pipe\s*)/__field(char, pipe_name)/
s/__entry\s*->\s*pipe\s*=\s*\([^;]\+\);/__entry->pipe_name = pipe_name(\1);/
s/pipe_name\s*(\s*__entry\s*->\s*pipe\s*)/__entry->pipe_name/
After these changes, using the same example, we have the following:
$ trace-cmd report \
> | sed -n 's/.*dev 0000:00:02\.0, \(pipe .\).*/\1/p' \
> | cat -v | sort | uniq -c
396 pipe A
34 pipe B
[1] https://lwn.net/Articles/379903/
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016135300.21428-4-gustavo.sousa@intel.com
With the rework of how the __string() handles dynamic strings where it
saves off the source string in field in the helper structure[1], the
assignment of that value to the trace event field is stored in the helper
value and does not need to be passed in again.
This means that with:
__string(field, mystring)
Which use to be assigned with __assign_str(field, mystring), no longer
needs the second parameter and it is unused. With this, __assign_str()
will now only get a single parameter.
There's over 700 users of __assign_str() and because coccinelle does not
handle the TRACE_EVENT() macro I ended up using the following sed script:
git grep -l __assign_str | while read a ; do
sed -e 's/\(__assign_str([^,]*[^ ,]\) *,[^;]*/\1)/' $a > /tmp/test-file;
mv /tmp/test-file $a;
done
I then searched for __assign_str() that did not end with ';' as those
were multi line assignments that the sed script above would fail to catch.
Note, the same updates will need to be done for:
__assign_str_len()
__assign_rel_str()
__assign_rel_str_len()
I tested this with both an allmodconfig and an allyesconfig (build only for both).
[1] https://lore.kernel.org/linux-trace-kernel/20240222211442.634192653@goodmis.org/
Link: https://lore.kernel.org/linux-trace-kernel/20240516133454.681ba6a0@rorschach.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Christian König <christian.koenig@amd.com> for the amdgpu parts.
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> #for
Acked-by: Rafael J. Wysocki <rafael@kernel.org> # for thermal
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Darrick J. Wong <djwong@kernel.org> # xfs
Tested-by: Guenter Roeck <linux@roeck-us.net>
Add display/intel_display_trace.[ch] for defining display
tracepoints. The main goal is to reduce cross-includes between gem and
display. It would be possible split up tracing even further, but that
would lead to more boilerplate.
We end up having to include intel_crtc.h in a few places because it was
pulled in implicitly via intel_de.h -> i915_trace.h -> intel_crtc.h, and
that's no longer the case.
There should be no changes to tracepoints.
v3:
- Rebase
v2:
- Define TRACE_INCLUDE_PATH relative to define_trace.h (Chris)
- Remove useless comments (Ville)
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/7862ad764fbd0748d903c76bc632d3d277874e5b.1638961423.git.jani.nikula@intel.com
