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f98919ec4f
Implements framework of 'perf kwork report', which is used to report
time properties such as run time and frequency:
Test cases:
# perf kwork
Usage: perf kwork [<options>] {record|report}
-D, --dump-raw-trace dump raw trace in ASCII
-f, --force don't complain, do it
-k, --kwork <kwork> list of kwork to profile (irq, softirq, workqueue, etc)
-v, --verbose be more verbose (show symbol address, etc)
# perf kwork report -h
Usage: perf kwork report [<options>]
-C, --cpu <cpu> list of cpus to profile
-i, --input <file> input file name
-n, --name <name> event name to profile
-s, --sort <key[,key2...]>
sort by key(s): runtime, max, count
-S, --with-summary Show summary with statistics
--time <str> Time span for analysis (start,stop)
# perf kwork report
Kwork Name | Cpu | Total Runtime | Count | Max runtime | Max runtime start | Max runtime end |
--------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------
# perf kwork report -S
Kwork Name | Cpu | Total Runtime | Count | Max runtime | Max runtime start | Max runtime end |
--------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------
Total count : 0
Total runtime (msec) : 0.000 (0.000% load average)
Total time span (msec) : 0.000
--------------------------------------------------------------------------------------------------------------------------------
# perf kwork report -C 0,100
Requested CPU 100 too large. Consider raising MAX_NR_CPUS
Invalid cpu bitmap
# perf kwork report -s runtime1
Error: Unknown --sort key: `runtime1'
Usage: perf kwork report [<options>]
-C, --cpu <cpu> list of cpus to profile
-i, --input <file> input file name
-n, --name <name> event name to profile
-s, --sort <key[,key2...]>
sort by key(s): runtime, max, count
-S, --with-summary Show summary with statistics
--time <str> Time span for analysis (start,stop)
# perf kwork report -i perf_no_exist.data
failed to open perf_no_exist.data: No such file or directory
# perf kwork report --time 00FFF,
Invalid time span
Since there are no report supported events, the output is empty.
Briefly describe the data structure:
1. "class" indicates event type. For example, irq and softiq correspond
to different types.
2. "cluster" refers to a specific event corresponding to a type. For
example, RCU and TIMER in softirq correspond to different clusters,
which contains three types of events: raise, entry, and exit.
3. "atom" includes time of each sample and sample of the previous phase.
(For example, exit corresponds to entry, which is used for timehist.)
Committer notes:
- Add {} for multiline if blocks.
- report_print_work() should either return that ret variable that
accounts how many bytes were printed or stop accounting and be void.
Do the former for now to avoid this:
builtin-kwork.c:534:6: error: variable 'ret' set but not used [-Werror,-Wunused-but-set-variable]
int ret = 0;
^
1 error generated.
When building with:
⬢[acme@toolbox perf]$ clang --version
clang version 13.0.0 (https://github.com/llvm/llvm-project e8991caea8690ec2d17b0b7e1c29bf0da6609076)
Also:
- if ((dst_type >= 0) && (dst_type < KWORK_TRACE_MAX)) {
+ if (dst_type < KWORK_TRACE_MAX) {
Several versions of clang and at least this gcc:
3 51.40 alpine:3.9 : FAIL gcc version 8.3.0 (Alpine 8.3.0)
builtin-kwork.c:411:16: error: comparison of unsigned enum expression >= 0 is
always true [-Werror,-Wtautological-compare]
if ((dst_type >= 0) && (dst_type < KWORK_TRACE_MAX)) {
As the first entry in a enum is zero.
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220709015033.38326-7-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.