From: Ross Zwisler <zwisler@google.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Linux Trace Devel <linux-trace-devel@vger.kernel.org>,
Ross Zwisler <zwisler@chromium.org>
Subject: Re: [PATCH] traceeval: Add way to extract the number of elements
Date: Mon, 2 Oct 2023 14:40:19 -0600 [thread overview]
Message-ID: <20231002204019.GK1532181@google.com> (raw)
In-Reply-To: <20230928102434.58e08f78@rorschach.local.home>
On Thu, Sep 28, 2023 at 10:24:34AM -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
>
> Add traceeval_count() that will return the number of elements in the
> traceeval. This can be useful for allocating an array to store the
> elements. By getting the count, the allocation can be done first and
> then iterated to load the elements into the array.
>
> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> ---
> include/traceeval-hist.h | 2 ++
> src/histograms.c | 11 +++++++++++
> 2 files changed, 13 insertions(+)
>
> diff --git a/include/traceeval-hist.h b/include/traceeval-hist.h
> index eefa48d..44d071f 100644
> --- a/include/traceeval-hist.h
> +++ b/include/traceeval-hist.h
> @@ -204,6 +204,8 @@ int traceeval_query_size(struct traceeval *teval, const struct traceeval_data *k
> void traceeval_results_release(struct traceeval *teval,
> const struct traceeval_data *results);
>
> +size_t traceeval_count(struct traceeval *teval);
> +
> #define traceeval_stat(teval, keys, type) \
> traceeval_stat_size(teval, keys, TRACEEVAL_ARRAY_SIZE(keys), type)
>
> diff --git a/src/histograms.c b/src/histograms.c
> index 2456342..ac3f7f7 100644
> --- a/src/histograms.c
> +++ b/src/histograms.c
> @@ -1006,6 +1006,17 @@ int traceeval_remove_size(struct traceeval *teval,
> return 1;
> }
>
> +/**
> + * traceeval_count - Return the number of elements in the traceeval
> + * @teval: The traceeval handle to get the count from
> + *
> + * Returns the number of elements stored by unique keys in the @teval.
> + */
> +size_t traceeval_count(struct traceeval *teval)
> +{
> + return teval->update_counter;
I don't think this is going to do what you want. 'teval->update_counter'
is a generation number, is monotonically increasing, and is incremented any
time an element is added or removed from the hash.
I think we either need to actually keep an element count (increment in
create_entry(), decrement in traceeval_remove_size() and
traceeval_iterator_remove()), or else we're going to have to count the
elements by walking the 'struct hash_table' buckets. Probably easier to just
keep an explicit element count.
> +}
> +
> /**
> * traceeval_iterator_put - release a given iterator
> * @iter: The iterartor to release
> --
> 2.40.1
>
prev parent reply other threads:[~2023-10-02 20:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-28 14:24 [PATCH] traceeval: Add way to extract the number of elements Steven Rostedt
2023-10-02 20:40 ` Ross Zwisler [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20231002204019.GK1532181@google.com \
--to=zwisler@google.com \
--cc=linux-trace-devel@vger.kernel.org \
--cc=rostedt@goodmis.org \
--cc=zwisler@chromium.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).