perf kwork: Implement BPF trace

'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>

1 files changed, 10 insertions, 0 deletions

diff --git a/tools/perf/Documentation/perf-kwork.txt b/tools/perf/Documentation/perf-kwork.txt
index 51c1625bacae..3c36324712b6 100644
--- a/tools/perf/Documentation/perf-kwork.txt
+++ b/tools/perf/Documentation/perf-kwork.txt
@@ -26,7 +26,9 @@ There are several variants of 'perf kwork':
     Example usage:
         perf kwork record -- sleep 1
         perf kwork report
+        perf kwork report -b
         perf kwork latency
+        perf kwork latency -b
         perf kwork timehist
 
    By default it shows the individual work events such as irq, workqeueu,
@@ -73,6 +75,10 @@ OPTIONS
 OPTIONS for 'perf kwork report'
 ----------------------------
 
+-b::
+--use-bpf::
+	Use BPF to measure kwork runtime
+
 -C::
 --cpu::
 	Only show events for the given CPU(s) (comma separated list).
@@ -103,6 +109,10 @@ OPTIONS for 'perf kwork report'
 OPTIONS for 'perf kwork latency'
 ----------------------------
 
+-b::
+--use-bpf::
+	Use BPF to measure kwork latency
+
 -C::
 --cpu::
 	Only show events for the given CPU(s) (comma separated list).