Lines Matching +full:ftrace +full:- +full:size
1 .. SPDX-License-Identifier: GPL-2.0
20 -------------
22 Mechanism to filter what ends up in the kernel log by dis-/en-abling log
29 - pr_debug()
30 - dev_dbg()
31 - print_hex_dump_debug()
32 - print_hex_dump_bytes()
45 $ ddcmd '-p; file v4l2-h264.c +p'
47 drivers/media/v4l2-core/v4l2-h264.c:372 [v4l2_h264]print_ref_list_b =p
49 drivers/media/v4l2-core/v4l2-h264.c:333 [v4l2_h264]print_ref_list_p =p
52 **When should you use this over Ftrace ?**
54 - When the code contains one of the valid print statements (see above) or when
56 - When timing is not an issue, meaning if multiple pr_debug() statements in
58 - When you care more about receiving specific log messages than tracing the
61 For the full documentation see :doc:`/admin-guide/dynamic-debug-howto`
63 Ftrace chapter
64 ------
74 - You can perform a function trace by adding a function name to the
78 at: :ref:`trace/ftrace:dynamic ftrace`).
79 - In order to find out where calls originate from you can activate the
81 - Tracing the children of a function call and showing the return values are
84 :ref:`trace/ftrace:dynamic ftrace with the function graph tracer`.
86 For the full Ftrace documentation see :doc:`/trace/ftrace`
90 :ref:`Creating a custom Ftrace tracepoint
91 <process/debugging/driver_development_debugging_guide:ftrace>`.
93 For the full Ftrace event tracing documentation see :doc:`/trace/events`
97 Reading the ftrace log
101 ``head``, ``vim``, etc.), the size of the file is limited by the
103 :ref:`trace/ftrace:trace_pipe` will behave similarly to the ``trace`` file, but
110 output of the `trace-cmd
111 <https://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git/>`__ application.
116 -------------------
128 - you cannot define the issue
129 - you do not know where it occurs
130 - the running system should not be interrupted or it is a remote system, where
139 - ``top`` / ``htop`` / ``atop`` (*get an overview of the system load, see
141 - ``mpstat -P ALL`` (*look at the load distribution among CPUs*)
142 - ``iostat -x`` (*observe input and output devices utilization and performance*)
143 - ``vmstat`` (*overview of memory usage on the system*)
144 - ``pidstat`` (*similar to* ``vmstat`` *but per process, to dial it down to the
146 - ``strace -tp $PID`` (*once you know the process, you can figure out how it
161 # perf stat -d find /usr -name 'gcc*' | wc -l
163 Performance counter stats for 'find /usr -name gcc*':
165 1277.81 msec task-clock # 0.997 CPUs utilized
166 9 context-switches # 7.043 /sec
167 1 cpu-migrations # 0.783 /sec
168 704 page-faults # 550.943 /sec
172 3842573 branch-misses # 6.67% of all branches (97.15%)
173 281616097 L1-dcache-loads # 220.390 M/sec (97.15%)
174 4220975 L1-dcache-load-misses # 1.50% of all L1-dcache accesses (97.15%)
175 <not supported> LLC-loads
176 <not supported> LLC-load-misses
205 * perfetto cross-platform performance analysis stack, has extended
211 ---------------------------
216 For the full documentation see the :doc:`/admin-guide/kdump/kdump`
223 derivatives for the different platforms like ``aarch64-linux-gnu-objdump``).
230 …aarch64-linux-gnu-objdump -dS drivers/staging/media/rkvdec/rockchip-vdec.ko | grep rkvdec_device_r…
236 ad4: a9bd7bfd stp x29, x30, [sp, #-48]!
240 const struct rkvdec_coded_fmt_desc *desc = ctx->coded_fmt_desc;
242 struct rkvdec_dev *rkvdec = ctx->dev;
246 ret = pm_runtime_resume_and_get(rkvdec->dev);
255 dev_warn(rkvdec->dev, "Not good\n");
257 b0c: 90000001 adrp x1, 0 <rkvdec_try_ctrl-0x8>