'perf record' can switch its output data file. The new output should
only store the data after switching. However, in overwrite backward
mode, the new output still can have data from before switching. That
also brings extra overhead.
At the end of mmap_read(), the position of the processed ring buffer is
saved in md->prev. Next mmap_read should be end in md->prev if it is not
overwriten. That avoids processing duplicate data. However, md->prev is
discarded. So next the mmap_read() has to process whole valid ring
buffer, which probably includes old processed data.
Avoid calling backward_rb_find_range() when md->prev is still
available.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Kan Liang <kan.liang@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mengting Zhang <zhangmengting@huawei.com>
Link: http://lkml.kernel.org/r/20171204165107.95327-3-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
All perf_mmap__read_forward() read from read-write ring buffer, so no
need check_messup. Reading from backward ring buffer doesn't require
check_messup because it never mess up. Cleanup arguments lists.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Link: http://lkml.kernel.org/r/20171203020044.81680-6-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
'overwrite' argument is always 'false'. Remove it from arguments list of
perf_mmap__push().
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Link: http://lkml.kernel.org/r/20171203020044.81680-5-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The previous prep patch was just to show exactly what changed in that
function, now its time to move that method and things only it uses to
the right place, mmap.[ch]
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-aaxywfgw3d44x6xlu8zm1avu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To better organize the sources, and we may end up even using it
directly, without evlists and evsels.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-oiqrm7grflurnnzo2ovfnslg@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
