From: Jeff King <peff@peff.net>
To: "SZEDER Gábor" <szeder.dev@gmail.com>
Cc: Rafael Silva <rafaeloliveira.cs@gmail.com>,
Jonathan Tan <jonathantanmy@google.com>,
Git Mailing List <git@vger.kernel.org>
Subject: [PATCH 0/3] low-hanging performance fruit with promisor packs
Date: Tue, 13 Apr 2021 03:12:54 -0400 [thread overview]
Message-ID: <YHVECXHfZ1bidTJH@coredump.intra.peff.net> (raw)
In-Reply-To: <YHTcHY+P7RuZJGab@coredump.intra.peff.net>
On Mon, Apr 12, 2021 at 07:47:41PM -0400, Jeff King wrote:
> The patch below drops the peak heap to 165MB. Still quite a bit more,
> but I think it's a combination of delta-base cache (96MB) plus extra
> structs for all the non-commit objects whose flags we marked.
I think we can do even better than that, after looking into the "do we
really need to parse the objects?" comment I left (spoiler: the answer
is no, we do not need to, at least for that caller).
Here are some cleaned-up patches that I think improve the situation
quite a bit. This is just the low-hanging fruit from this part of the
discussion; I'm sure there's more to do to make using partial clones
pleasant. In particular:
- this does nothing for the "oops, we turned all of the promisor
objects loose and then deleted them" problem. Hopefully Rafael
will produce a nice patch for that
- In is_promisor_object(), we still call parse_object(), because it
really does look at the contents. But doing so for blobs is wasteful
(it's a lot of bytes we push through sha1, and we don't even look at
them). It might be worth using oid_object_info() to avoid this. This
introduces a little overhead, but I think would be a net win (it
would be really nice if we could amortize the object lookup work;
i.e., if there was a way to call oid_object_info_extended() and say
"open the object and look at the type; only return the contents if
it's a non-blob").
- I still think it's probably worth having a mode where we store the
set of pointed-to objects we don't have, rather than parsing on the
fly. This could easily be made optional (it's a good thing if you
_have_ a lot of objects that point to a small or moderate number of
missing objects, like a blob:limit or blob:none filter; it's a bad
thing if you have very few objects but they point to a very large
number).
I didn't explore any of those here, and I don't plan to look into them
anytime soon. I'm just documenting my findings for later.
Anyway, here are the patches.
[1/3]: is_promisor_object(): free tree buffer after parsing
[2/3]: lookup_unknown_object(): take a repository argument
[3/3]: revision: avoid parsing with --exclude-promisor-objects
builtin/fsck.c | 2 +-
builtin/pack-objects.c | 2 +-
http-push.c | 2 +-
object.c | 7 +++----
object.h | 2 +-
packfile.c | 1 +
refs.c | 2 +-
revision.c | 2 +-
t/helper/test-example-decorate.c | 6 +++---
t/perf/p5600-partial-clone.sh | 12 ++++++++++++
upload-pack.c | 2 +-
walker.c | 2 +-
12 files changed, 27 insertions(+), 15 deletions(-)
-Peff
next prev parent reply other threads:[~2021-04-13 7:12 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-03 9:04 rather slow 'git repack' in 'blob:none' partial clones SZEDER Gábor
2021-04-05 1:02 ` Rafael Silva
2021-04-07 21:17 ` Jeff King
2021-04-08 0:02 ` Jonathan Tan
2021-04-08 0:35 ` Jeff King
2021-04-12 7:09 ` Rafael Silva
2021-04-12 21:36 ` SZEDER Gábor
2021-04-12 21:49 ` Bryan Turner
2021-04-12 23:51 ` Jeff King
2021-04-12 23:47 ` Jeff King
2021-04-13 7:12 ` Jeff King [this message]
2021-04-13 7:15 ` [PATCH 1/3] is_promisor_object(): free tree buffer after parsing Jeff King
2021-04-13 20:17 ` Junio C Hamano
2021-04-14 5:18 ` Jeff King
2021-04-13 7:16 ` [PATCH 2/3] lookup_unknown_object(): take a repository argument Jeff King
2021-04-13 7:17 ` [PATCH 3/3] revision: avoid parsing with --exclude-promisor-objects Jeff King
2021-04-13 20:22 ` Junio C Hamano
2021-04-13 18:10 ` [PATCH 0/3] low-hanging performance fruit with promisor packs SZEDER Gábor
2021-04-14 17:14 ` Jonathan Tan
2021-04-14 19:22 ` Rafael Silva
2021-04-13 18:05 ` rather slow 'git repack' in 'blob:none' partial clones SZEDER Gábor
2021-04-14 5:14 ` Jeff King
2021-04-11 10:59 ` SZEDER Gábor
2021-04-12 7:53 ` Rafael Silva
2021-04-14 19:14 ` [PATCH 0/2] prevent `repack` to unpack and delete promisor objects Rafael Silva
2021-04-14 19:14 ` [PATCH 1/2] repack: teach --no-prune-packed to skip `git prune-packed` Rafael Silva
2021-04-14 23:50 ` Jonathan Tan
2021-04-18 14:15 ` Rafael Silva
2021-04-14 19:14 ` [PATCH 2/2] repack: avoid loosening promisor pack objects in partial clones Rafael Silva
2021-04-15 1:04 ` Jonathan Tan
2021-04-15 3:51 ` Junio C Hamano
2021-04-15 9:03 ` Jeff King
2021-04-15 9:05 ` Jeff King
2021-04-18 7:12 ` Rafael Silva
2021-04-15 18:06 ` Junio C Hamano
2021-04-18 8:40 ` Rafael Silva
2021-04-14 22:10 ` [PATCH 0/2] prevent `repack` to unpack and delete promisor objects Junio C Hamano
2021-04-15 9:15 ` Jeff King
2021-04-18 8:20 ` Rafael Silva
2021-04-18 13:57 ` [PATCH v2 0/1] " Rafael Silva
2021-04-18 13:57 ` [PATCH v2 1/1] repack: avoid loosening promisor objects in partial clones Rafael Silva
2021-04-19 19:15 ` Jonathan Tan
2021-04-21 18:54 ` Rafael Silva
2021-04-19 23:09 ` Junio C Hamano
2021-04-21 19:25 ` Rafael Silva
2021-04-21 19:32 ` [PATCH v3] " Rafael Silva
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=YHVECXHfZ1bidTJH@coredump.intra.peff.net \
--to=peff@peff.net \
--cc=git@vger.kernel.org \
--cc=jonathantanmy@google.com \
--cc=rafaeloliveira.cs@gmail.com \
--cc=szeder.dev@gmail.com \
/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 NNTP newsgroup(s).