On Mon, Nov 13, 2017 at 01:38:09AM +0000, Wang Nan wrote:
> After removing the concept of 'overwrite' in code level, now the
> prot is determinated by write_backward. There's no need to pass
> prot from perf_evlist__mmap_ex().
>
> Signed-off-by: Wang Nan <wangn...@huawei.com>
> ---
> tools/perf/util/evlist.c | 17 ++++++-----------
> tools/perf/util/mmap.c | 4 ++--
> tools/perf/util/mmap.h | 4 ++--
> 3 files changed, 10 insertions(+), 15 deletions(-)
>
> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> index 4948d3d..0d713e0 100644
> --- a/tools/perf/util/evlist.c
> +++ b/tools/perf/util/evlist.c
> @@ -799,28 +799,23 @@ perf_evlist__should_poll(struct perf_evlist *evlist
> __maybe_unused,
> }
>
> static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx,
> - struct mmap_params *_mp, int cpu_idx,
> + struct mmap_params *mp, int cpu_idx,
> int thread, int *_output, int
> *_output_backward)
> {
> struct perf_evsel *evsel;
> int revent;
> int evlist_cpu = cpu_map__cpu(evlist->cpus, cpu_idx);
> - struct mmap_params *mp;
>
> evlist__for_each_entry(evlist, evsel) {
> struct perf_mmap *maps = evlist->mmap;
> - struct mmap_params rdonly_mp;
> int *output = _output;
> int fd;
> int cpu;
> + int prot = PROT_READ;
can't you set the PROT_READ in struct mmap_params *mp as its default value?
mp->prot = PROT_READ;
>
> - mp = _mp;
> if (evsel->attr.write_backward) {
> output = _output_backward;
> maps = evlist->backward_mmap;
> - rdonly_mp = *_mp;
> - rdonly_mp.prot &= ~PROT_WRITE;
> - mp = &rdonly_mp;
>
> if (!maps) {
> maps = perf_evlist__alloc_mmap(evlist);
> @@ -830,6 +825,8 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist
> *evlist, int idx,
> if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY)
> perf_evlist__toggle_bkw_mmap(evlist,
> BKW_MMAP_RUNNING);
> }
> + } else {
> + prot |= PROT_WRITE;
> }
>
> if (evsel->system_wide && thread)
> @@ -844,7 +841,7 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist
> *evlist, int idx,
> if (*output == -1) {
> *output = fd;
>
> - if (perf_mmap__mmap(&maps[idx], mp, *output) < 0)
> + if (perf_mmap__mmap(&maps[idx], mp, prot, *output) < 0)
so there's no need for the extra 'prot' param in here
jirka
