Re: [PATCH v5 7/9] perf auxtrace: Remove auxtrace_mmap__read_snapshot_head()
From: Arnaldo Carvalho de Melo
Date: Mon Aug 09 2021 - 16:01:42 EST
Em Mon, Aug 09, 2021 at 07:14:05PM +0800, Leo Yan escreveu:
> Since the function auxtrace_mmap__read_snapshot_head() is exactly same
> with auxtrace_mmap__read_head(), whether the session is in snapshot mode
> or not, it's unified to use function auxtrace_mmap__read_head() for
> reading AUX buffer head.
>
> And the function auxtrace_mmap__read_snapshot_head() is unused so this
> patch removes it.
Thanks, applied to perf/core.
- Arnaldo
> Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
> ---
> tools/perf/util/auxtrace.c | 13 +++++--------
> tools/perf/util/auxtrace.h | 10 ----------
> 2 files changed, 5 insertions(+), 18 deletions(-)
>
> diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
> index cb19669d2a5b..2dcf3d12ba32 100644
> --- a/tools/perf/util/auxtrace.c
> +++ b/tools/perf/util/auxtrace.c
> @@ -1686,14 +1686,11 @@ static int __auxtrace_mmap__read(struct mmap *map,
> union perf_event ev;
> void *data1, *data2;
>
> - if (snapshot) {
> - head = auxtrace_mmap__read_snapshot_head(mm);
> - if (auxtrace_record__find_snapshot(itr, mm->idx, mm, data,
> - &head, &old))
> - return -1;
> - } else {
> - head = auxtrace_mmap__read_head(mm);
> - }
> + head = auxtrace_mmap__read_head(mm);
> +
> + if (snapshot &&
> + auxtrace_record__find_snapshot(itr, mm->idx, mm, data, &head, &old))
> + return -1;
>
> if (old == head)
> return 0;
> diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
> index 4f9176368134..d68a5e80b217 100644
> --- a/tools/perf/util/auxtrace.h
> +++ b/tools/perf/util/auxtrace.h
> @@ -440,16 +440,6 @@ struct auxtrace_cache;
>
> #ifdef HAVE_AUXTRACE_SUPPORT
>
> -static inline u64 auxtrace_mmap__read_snapshot_head(struct auxtrace_mmap *mm)
> -{
> - struct perf_event_mmap_page *pc = mm->userpg;
> - u64 head = READ_ONCE(pc->aux_head);
> -
> - /* Ensure all reads are done after we read the head */
> - smp_rmb();
> - return head;
> -}
> -
> static inline u64 auxtrace_mmap__read_head(struct auxtrace_mmap *mm)
> {
> struct perf_event_mmap_page *pc = mm->userpg;
> --
> 2.25.1
>
--
- Arnaldo