'perf record' generates perf.data, which generates extra interrupts
for hard disk, amount of data to be collected increases with time.
Using eBPF trace can process the data in kernel, which solves the
preceding two problems.
Add -b/--use-bpf option for latency and report to support
tracing kwork events using eBPF:
1. Create bpf prog and attach to tracepoints,
2. Start tracing after command is entered,
3. After user hit "ctrl+c", stop tracing and report,
4. Support CPU and name filtering.
This commit implements the framework code and
does not add specific event support.
Test cases:
# perf kwork rep -h
Usage: perf kwork report [<options>]
-b, --use-bpf Use BPF to measure kwork runtime
-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 lat -h
Usage: perf kwork latency [<options>]
-b, --use-bpf Use BPF to measure kwork latency
-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): avg, max, count
--time <str> Time span for analysis (start,stop)
# perf kwork lat -b
Unsupported bpf trace class irq
# perf kwork rep -b
Unsupported bpf trace class irq
Signed-off-by: Yang Jihong <yangjihong1@huawei.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/20220709015033.38326-15-yangjihong1@huawei.com
[ Simplify work_findnew() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Implements framework of perf kwork latency, which is used to report time
properties such as delay time and frequency.
Test cases:
# perf kwork lat -h
Usage: perf kwork latency [<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): avg, max, count
--time <str> Time span for analysis (start,stop)
# perf kwork lat -C 199
Requested CPU 199 too large. Consider raising MAX_NR_CPUS
Invalid cpu bitmap
# perf kwork lat -i perf_no_exist.data
failed to open perf_no_exist.data: No such file or directory
# perf kwork lat -s avg1
Error: Unknown --sort key: `avg1'
Usage: perf kwork latency [<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): avg, max, count
--time <str> Time span for analysis (start,stop)
# perf kwork lat --time FFFF,
Invalid time span
# perf kwork lat
Kwork Name | Cpu | Avg delay | Count | Max delay | Max delay start | Max delay end |
--------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------------------------------------------------
INFO: 36.570% skipped events (31537 including 0 raise, 31537 entry, 0 exit)
Since there are no latency-enabled events, the output is empty.
Signed-off-by: Yang Jihong <yangjihong1@huawei.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/20220709015033.38326-11-yangjihong1@huawei.com
[ Add {} for multiline if blocks ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
Record interrupt events irq:irq_handler_entry & irq_handler_exit
Test cases:
# perf kwork record -o perf_kwork.date -- sleep 1
[ perf record: Woken up 0 times to write data ]
[ perf record: Captured and wrote 0.556 MB perf_kwork.date ]
#
# perf evlist -i perf_kwork.date
irq:irq_handler_entry
irq:irq_handler_exit
dummy:HG
# Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events
#
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/20220709015033.38326-3-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The 'perf kwork' tool is used to trace time properties of kernel work
(such as irq, softirq, and workqueue), including runtime, latency, and
timehist, using the infrastructure in the perf tools to allow tracing
extra targets.
This is the first commit to reuse the 'perf record' framework code to
implement a simple record function, kwork is not supported currently.
Test cases:
# perf
usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]
The most commonly used perf commands are:
<SNIP>
iostat Show I/O performance metrics
kallsyms Searches running kernel for symbols
kmem Tool to trace/measure kernel memory properties
kvm Tool to trace/measure kvm guest os
kwork Tool to trace/measure kernel work properties (latencies)
list List all symbolic event types
lock Analyze lock events
mem Profile memory accesses
record Run a command and record its profile into perf.data
<SNIP>
See 'perf help COMMAND' for more information on a specific command.
# perf kwork
Usage: perf kwork [<options>] {record}
-D, --dump-raw-trace dump raw trace in ASCII
-f, --force don't complain, do it
-k, --kwork <kwork> list of kwork to profile
-v, --verbose be more verbose (show symbol address, etc)
# perf kwork record -- sleep 1
[ perf record: Woken up 0 times to write data ]
[ perf record: Captured and wrote 1.787 MB perf.data ]
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/20220709015033.38326-2-yangjihong1@huawei.com
[ Add {} for multiline if blocks ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Yang Jihong