kernel/tools/perf/util/mmap.h, branch linux-4.17.y

perf mmap: Simplify perf_mmap__read_init()

2018-03-08T13:05:53Z

It isn't necessary to pass the 'start', 'end' and 'overwrite' arguments to perf_mmap__read_init(). The data is stored in the struct perf_mmap. Discard the parameters. Signed-off-by: Kan Liang Suggested-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/1520350567-80082-8-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Simplify perf_mmap__read_event()

2018-03-08T13:05:53Z

It isn't necessary to pass the 'overwrite', 'start' and 'end' argument to perf_mmap__read_event(). Discard them. Signed-off-by: Kan Liang Suggested-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/1520350567-80082-7-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Simplify perf_mmap__consume()

2018-03-08T13:05:52Z

It isn't necessary to pass the 'overwrite' argument to perf_mmap__consume(). Discard it. Signed-off-by: Kan Liang Suggested-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/1520350567-80082-6-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Use the stored scope data in perf_mmap__push()

2018-03-08T13:05:51Z

Using the 'start' and 'end' which are stored in struct perf_mmap to replace the temporary 'start' and 'end'. The temporary variables will be discarded later. It doesn't need to pass 'overwrite' to perf_mmap__push(). It's stored in struct perf_mmap. Signed-off-by: Kan Liang Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/1520350567-80082-3-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Store mmap scope in struct perf_mmap()

2018-03-08T13:05:50Z

There is too much boilerplate in the perf_mmap__read*() interfaces. The 'start' and 'end' variables should be stored in struct perf_mmap at initialization. They will be used later. The old 'startp' and 'endp' pointers are used by perf_mmap__read_event() now. They cannot be removed. So the old 'startp/endp' and new 'md->start/md->end' will exist simultaneously now. The old one will be removed later. Signed-off-by: Kan Liang Suggested-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/1520350567-80082-2-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Store 'overwrite' in struct perf_mmap

2018-03-08T13:05:50Z

It has been determined that the map is for overwrite mode (evlist->overwrite_mmap) or non-overwrite mode (evlist->mmap) when calling perf_evlist__alloc_mmap(). Store the information in struct perf_mmap, which will be used later to simplify the perf_mmap__read*() interfaces. Signed-off-by: Kan Liang Suggested-by: Jiri Olsa Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/r/1520350567-80082-1-git-send-email-kan.liang@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Discard legacy interface for mmap read

2018-02-15T12:54:17Z

Discards perf_mmap__read_backward() and perf_mmap__read_catchup(). No tools use them. There are tools still use perf_mmap__read_forward(). Keep it, but add comments to point to the new interface for future use. Signed-off-by: Kan Liang Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Jin Yao Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1516310792-208685-11-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Introduce perf_mmap__read_event()

2018-02-15T12:53:40Z

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 Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Jin Yao Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1516310792-208685-9-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Introduce perf_mmap__read_done()

2018-02-15T12:53:15Z

The direction of overwrite mode is backward. The last perf_mmap__read() will set tail to map->prev. Need to correct the map->prev to head which is the end of next read. It will be used later. Signed-off-by: Kan Liang Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Jin Yao Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1516310792-208685-8-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf mmap: Introduce perf_mmap__read_init()

2018-02-15T12:52:22Z

The new function perf_mmap__read_init() is factored out from perf_mmap__push(). It is to calculate the 'start' and 'end' of the available data in ringbuffer. No functional change. Signed-off-by: Kan Liang Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Jin Yao Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1516310792-208685-5-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo