On 23 June 2016 at 00:27, Wang Nan <wangn...@huawei.com> wrote: > An auxiliary evlist is created by perf_evlist__new_aux() using an > existing evlist as its parent. An auxiliary evlist can have its own > 'struct perf_mmap', but can't have any other data. User should use its > parent instead when accessing other data. > > Auxiliary evlists are containers of 'struct perf_mmap'. It is introduced > to allow its parent evlist to map different events into separated mmaps. > > Following commits create an auxiliary evlist for overwritable > events, because overwritable events need a read only and backwards ring > buffer, which is different from normal events. > > To achieve this goal, this patch carefully changes 'evlist' to > 'evlist->parent' in all functions in the path of 'perf_evlist__mmap_ex', > except 'evlist->mmap' related operations, to make sure all evlist > modifications (like pollfd and event id hash tables) goes to original > evlist. > > A 'evlist->parent' pointer is added to 'struct perf_evlist' and points to > the evlist itself for normal evlists. > > Children of one evlist are linked into it so one can find all children > from its parent. > > To avoid potential complexity, forbid creating aux evlist from another > aux evlist. > > Improve perf_evlist__munmap_filtered(), so when recording, if an event > is terminated, unmap mmaps, from parent and children. > > Signed-off-by: Wang Nan <wangn...@huawei.com> > Cc: He Kuang <heku...@huawei.com> > Cc: Jiri Olsa <jo...@kernel.org> > Cc: Masami Hiramatsu <mhira...@kernel.org> > Cc: Namhyung Kim <namhy...@kernel.org> > Cc: Zefan Li <lize...@huawei.com> > Cc: pi3or...@163.com > --- > tools/perf/util/evlist.c | 49 > +++++++++++++++++++++++++++++++++++++----------- > tools/perf/util/evlist.h | 12 ++++++++++++ > 2 files changed, 50 insertions(+), 11 deletions(-)
Wang, thanks for making the change. The patch seems perfectly fine to me. -- Nilay
