This is v2 of this series. Compare with v1:
Fixes several bugs in v1. Corresponsing perf has finished and can be found from: https://git.kernel.org/cgit/linux/kernel/git/pi3orama/linux.git/ branch: perf/overwrite-benchmark Some benchmarking results can be found from [1]. Summary: On a PC with Intel E5-2640 0 @ 2.50GHz CPU, execute close(-1) 3000000 times, capture raw_syscalls:* with perf into overwrite ring buffer, check total time (in us): MEAN STDVAR BASE : 879870.81 11913.13 RAWPERF : 2603854.7 706658.4 WRTBKWRD : 2313301.220 6727.957 TAILSIZE : 2383051.860 5248.061 RAWOVWRT : 2315273.180 5221.025 RAWOVWRT*: 2323970.45 5103.39 Where: BASE: don't use perf at all. RAWPERF: use non-overwrite ring buffer, perf collects all data, write to /dev/null WRTBKWRD: Use backward writing ring buffer, write from tail to head, never wakeup perf, collect data when exiting. TAILSIZE: Use tailsize ring buffer, pad 8 bytes for the size of the record for each event, never wakeup perf, collect data when exiting. RAWOVWRT: Use raw overwrite ring buffer, never wakeup perf, don't collect data at all. RAWOVWRT*: Same as RAWOVWRT, without this patchset. The benchmarking results shows WRTBKWRD is good enough. I suggest not to implement TAILSIZE and tail-header ring buffer. I will post the result on a smartphone next week. [1] http://lkml.kernel.org/g/56a07ff3.2090...@huawei.com Wang Nan (6): perf core: Introduce new ioctl options to pause and resume ring buffer perf core: Set event's default overflow_handler perf core: Prepare writing into ring buffer from end perf core: Add backward attribute to perf event perf core: Reduce perf event output overhead by setting overwrite handler perf core: Put size of a sample at the end of it by PERF_SAMPLE_TAILSIZE include/linux/perf_event.h | 39 +++++++--- include/uapi/linux/perf_event.h | 7 +- kernel/events/core.c | 155 +++++++++++++++++++++++++++++++--------- kernel/events/internal.h | 11 +++ kernel/events/ring_buffer.c | 70 +++++++++++++++--- 5 files changed, 228 insertions(+), 54 deletions(-) Signed-off-by: Wang Nan <wangn...@huawei.com> Cc: He Kuang <heku...@huawei.com> Cc: Alexei Starovoitov <a...@kernel.org> Cc: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Brendan Gregg <brendan.d.gr...@gmail.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com -- 1.8.3.4
