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Subject[PATCH 00/10] new mmap_read interfaces for ring buffer
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From: Kan Liang <kan.liang@intel.com>

The mmap_read interfaces for ring buffer has some issues
- Not well organized. For example, perf record maintains some codes in
builtin-record.c. Other perf tools use perf_mmap__read* functions to
access ring buffer. Some of the codes should be shared.
- Only support forward mode. Although there is
perf_mmap__read_backward, no one use it. It's not well maintained.
But perf top need to switch to overwrite backward mode for good
performance.
- There is bug found on overwrite backward mode.

The patch series will move all the mmap_read related code to evlist.c,
and provide new standard interfaces to access ring buffer.
The new interfaces include,
perf_evlist__mmap_read_init //wrapper of perf_mmap__read_init
perf_mmap__read_init //Initialization and calculate the range
perf_mmap__read_to_file //read the ring buffer and write to file
perf_mmap__read_event //read the event in specified range
perf_mmap__read_done //Update the md->prev for later use

For perf record, it needs to read all available data in ring buffer and
write them to perf.data file.
It can be done as below,
perf_mmap__read_init
perf_mmap__read_to_file
perf_mmap__consume

For other perf tools, it needs to read and process events one by one.
It can be done as below,
perf_mmap__read_init
while (event = perf_mmap__read_event) {
//process the event
perf_mmap__consume
}
perf_mmap__read_done


All the stale interfaces will be removed, which include
perf_evlist__mmap_read
perf_evlist__mmap_read_forward
perf_evlist__mmap_read_backward
perf_evlist__mmap_read_catchup
perf_mmap__read_catchup
perf_mmap__read_forward
perf_mmap__read_backward

The patch series only changes the interfaces. It doesn't change the
core perf_mmap__read function. There is no functional change.

Kan Liang (10):
perf record: new interfaces to read ring buffer to file
perf tool: fix: Don't discard prev in backward mode
perf tool: new functions to read event from ring buffer
perf tool: perf_mmap__read_init wraper for evlist
perf top: apply new mmap_read interfaces
perf trace: apply new mmap_read interfaces
perf kvm: apply new mmap_read interfaces
perf python: apply new mmap_read interfaces
perf tests: apply new mmap_read interfaces
perf tool: remove stale mmap_read interfaces

tools/perf/arch/x86/tests/perf-time-to-tsc.c | 9 +-
tools/perf/builtin-kvm.c | 10 +-
tools/perf/builtin-record.c | 111 +++---------
tools/perf/builtin-top.c | 9 +-
tools/perf/builtin-trace.c | 9 +-
tools/perf/tests/backward-ring-buffer.c | 10 +-
tools/perf/tests/bpf.c | 10 +-
tools/perf/tests/code-reading.c | 8 +-
tools/perf/tests/keep-tracking.c | 8 +-
tools/perf/tests/mmap-basic.c | 9 +-
tools/perf/tests/openat-syscall-tp-fields.c | 9 +-
tools/perf/tests/perf-record.c | 9 +-
tools/perf/tests/sw-clock.c | 8 +-
tools/perf/tests/switch-tracking.c | 8 +-
tools/perf/tests/task-exit.c | 8 +-
tools/perf/util/evlist.c | 244 +++++++++++++++++----------
tools/perf/util/evlist.h | 31 ++--
tools/perf/util/python.c | 9 +-
18 files changed, 314 insertions(+), 205 deletions(-)

--
2.5.5

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