perf mmap: Introduce perf_mmap__read_event()
authorKan Liang <kan.liang@intel.com>
Thu, 18 Jan 2018 21:26:23 +0000 (13:26 -0800)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Thu, 15 Feb 2018 12:53:40 +0000 (09:53 -0300)
commit7bb45972952db9298fe5cc440160dcad1a66bfbc
treec7642dbb2f3e4c5a9be33ac4c891c102b3424928
parentee023de05f35484691f7d9e5c1f92195ac4d64d2
perf mmap: Introduce perf_mmap__read_event()

Except for 'perf record', the other perf tools read events one by one
from the ring buffer using perf_mmap__read_forward(). But it only
supports non-overwrite mode.

Introduce perf_mmap__read_event() to support both non-overwrite and
overwrite mode.

Usage:
perf_mmap__read_init()
while(event = perf_mmap__read_event()) {
        //process the event
        perf_mmap__consume()
}
perf_mmap__read_done()

It cannot use perf_mmap__read_backward(). Because it always reads the
stale buffer which is already processed. Furthermore, the forward and
backward concepts have been removed. The perf_mmap__read_backward() will
be replaced and discarded later.

Signed-off-by: Kan Liang <kan.liang@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1516310792-208685-9-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/util/mmap.c
tools/perf/util/mmap.h