From: Jeff Hostetler <git@jeffhostetler.com>
To: Josh Steadmon <steadmon@google.com>, git@vger.kernel.org
Subject: Re: [PATCH] fetch-pack: add tracing for negotiation rounds
Date: Mon, 25 Jul 2022 20:04:50 -0400 [thread overview]
Message-ID: <16998c06-8394-1c8a-06d1-0f7ac4034cf4@jeffhostetler.com> (raw)
In-Reply-To: <a16d86e1ced104bb331bb9e7055037a3a2821352.1658787182.git.steadmon@google.com>
On 7/25/22 6:13 PM, Josh Steadmon wrote:
> Currently, negotiation for V0/V1/V2 fetch have trace2 regions covering
> the entire negotiation process. However, we'd like additional data, such
> as timing for each round of negotiation or the number of "haves" in each
> round. Additionally, "independent negotiation" (AKA push negotiation)
> has no tracing at all. Having this data would allow us to compare the
> performance of the various negotation implementations, and to debug
> unexpectedly slow fetch & push sessions.
>
> Fix this by adding per-round trace2 regions for all negotiation
> implementations (V0+V1, V2, and independent negotiation), as well as an
> overall region for independent negotiation. Add trace2 data logging for
> the number of haves and "in vain" objects for each round, and for the
> total number of rounds once negotiation completes. Finally, add a few
> checks into various tests to verify that the number of rounds is logged
> as expected.
I've been wanting to add data like this around the negotiation
code for a while now. Thanks!
>
> Signed-off-by: Josh Steadmon <steadmon@google.com>
> ---
> fetch-pack.c | 62 +++++++++++++++++++++++++++++-
> t/t5500-fetch-pack.sh | 4 +-
> t/t5516-fetch-push.sh | 10 ++++-
> t/t5601-clone.sh | 6 ++-
> t/t5703-upload-pack-ref-in-want.sh | 6 ++-
> 5 files changed, 81 insertions(+), 7 deletions(-)
>
> diff --git a/fetch-pack.c b/fetch-pack.c
> index cb6647d657..01a451e456 100644
> --- a/fetch-pack.c
> +++ b/fetch-pack.c
> @@ -299,6 +299,7 @@ static int find_common(struct fetch_negotiator *negotiator,
> {
> int fetching;
> int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
> + int negotiation_round = 0, haves = 0;
> const struct object_id *oid;
> unsigned in_vain = 0;
> int got_continue = 0;
> @@ -441,9 +442,19 @@ static int find_common(struct fetch_negotiator *negotiator,
> packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
> print_verbose(args, "have %s", oid_to_hex(oid));
> in_vain++;
> + haves++;
> if (flush_at <= ++count) {
> int ack;
>
> + negotiation_round++;
> + trace2_region_enter_printf("negotiation_v0_v1", "round",
> + the_repository, "round-%d",
> + negotiation_round);
I'm wondering here if the "round-%d" should have some number
of leading zeros so that multiple rounds will sort correctly
when you have a bunch of them.
I'm also wondering (and this is more of a style thing, so feel
free to ignore) if we could just use trace2_region_enter()
and make the "label" field be the "round/%04d" and not need
the extra args.
> + trace2_data_intmax("negotiation_v0_v1", the_repository,
> + "haves_added", haves);
> + trace2_data_intmax("negotiation_v0_v1", the_repository,
> + "in_vain", in_vain);
> + haves = 0;
Thanks,
Jeff
next prev parent reply other threads:[~2022-07-26 0:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-25 22:13 [PATCH] fetch-pack: add tracing for negotiation rounds Josh Steadmon
2022-07-25 23:07 ` Junio C Hamano
2022-08-02 21:51 ` Josh Steadmon
2022-07-26 0:04 ` Jeff Hostetler [this message]
2022-08-02 21:52 ` Josh Steadmon
2022-08-02 22:04 ` [PATCH v2] " Josh Steadmon
2022-08-15 15:08 ` Jeff Hostetler
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