linux-kernel - Re: [PATCH v1 08/15] perf record: write trace data into mmap trace files

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Message-ID: <CAM9d7cgrXsiPWuAYjg1og0N=03-mfx075-n7KUrvYyAMLZ8_7A@mail.gmail.com>
Date:   Wed, 14 Oct 2020 19:52:01 +0900
From:   Namhyung Kim <namhyung@...nel.org>
To:     Alexey Budankov <alexey.budankov@...ux.intel.com>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Jiri Olsa <jolsa@...hat.com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1 08/15] perf record: write trace data into mmap trace files

Hi,

On Mon, Oct 12, 2020 at 6:01 PM Alexey Budankov
<alexey.budankov@...ux.intel.com> wrote:
>
>
> Write trace data into per mmap trace files located
> at data directory. Streaming thread adjusts its affinity
> according to mask of the buffer being processed.
>
> Signed-off-by: Alexey Budankov <alexey.budankov@...ux.intel.com>
> ---
[SNIP]
> @@ -1184,8 +1203,12 @@ static int record__mmap_read_evlist(struct record *rec, struct evlist *evlist,
>         /*
>          * Mark the round finished in case we wrote
>          * at least one event.
> +        *
> +        * No need for round events in directory mode,
> +        * because per-cpu maps and files have data
> +        * sorted by kernel.
>          */
> -       if (bytes_written != rec->bytes_written)
> +       if (!record__threads_enabled(rec) && bytes_written != rec->bytes_written)
>                 rc = record__write(rec, NULL, &finished_round_event, sizeof(finished_round_event));

This means it needs to keep all events in the ordered events queue
when perf report processes the data, right?

Thanks
Namhyung