From: Patrick Steinhardt <ps@pks•im>
To: Jeff King <peff@peff•net>
Cc: Karthik Nayak <karthik.188@gmail•com>, git@vger•kernel.org
Subject: Re: [PATCH 05/16] odb: move MRU list of packfiles into `struct packfile_store`
Date: Thu, 21 Aug 2025 08:40:30 +0200 [thread overview]
Message-ID: <aKa_V_Iyv4Kwtmx6@pks.im> (raw)
In-Reply-To: <20250820192008.GA1662788@coredump.intra.peff.net>
On Wed, Aug 20, 2025 at 03:20:08PM -0400, Jeff King wrote:
> On Wed, Aug 20, 2025 at 05:44:36AM -0700, Karthik Nayak wrote:
>
> > Question: for my understanding, so we maintain a list of `packed_git`
> > packfiles in `packfile_store.packs` and then the same list is
> > available in a MRU form in `packfile_store.mru`?
> >
> > I assume this is to optimize searches to use the mru form? Is there a
> > reason to not pick the mru list?
>
> Yeah, I believe you should find the same packfiles in the linked list
> currently formed by packed_git.next and the MRU list. When I introduced
> the MRU list long ago, I cowardly did not want to take the risk that
> somebody depended on the order of the original list, and left it in
> place.
>
> I think it would _probably_ be OK to just keep a single list (and
> manipulate it to keep the MRU property). But whoever does should take a
> close look and make sure that is true. The biggest risk I can think of
> is that there could be some code iterating over the packfiles, coupled
> with object lookups in their loop body. If those lookups reorder the
> list, that would screw up the iteration.
>
> IMHO it is probably better to do a change like that outside of Patrick's
> series. There already is a lot going on with moving fields around, and
> consolidating the lists can happen on top (and would be made easier for
> having pulled it out into two adjacent lists).
There's in fact been a couple sites where we _didn't_ add packfiles to
the MRU list: "builtin/fast-import.c", "builtin/index-pack.c",
"packfile.c" via `prepare_pack()`. This is no longer going to be the
case at the end of this patch series as we in a later patch adjust
`packfile_store_store_add()` to handle this for us.
But I agree, this is something I'd rather want to push into a subsequent
patch series. I've already got one cooking where I change how the lists
are getting handled, so that's a good opportunity to do so.
Patrick
next prev parent reply other threads:[~2025-08-21 6:40 UTC|newest]
Thread overview: 181+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-19 8:19 [PATCH 00/16] packfile: carve out a new packfile store Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 01/16] packfile: introduce a new `struct packfile_store` Patrick Steinhardt
2025-08-19 9:47 ` Karthik Nayak
2025-08-20 4:58 ` Patrick Steinhardt
2025-08-19 17:32 ` Junio C Hamano
2025-08-20 4:58 ` Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 02/16] odb: move list of packfiles into " Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 03/16] odb: move initialization bit " Patrick Steinhardt
2025-08-19 9:57 ` Karthik Nayak
2025-08-19 16:24 ` Junio C Hamano
2025-08-20 8:04 ` Karthik Nayak
2025-08-22 23:50 ` Junio C Hamano
2025-08-26 12:19 ` [PATCH] Documentation: note styling for bit fields Karthik Nayak
2025-08-20 4:58 ` [PATCH 03/16] odb: move initialization bit into `struct packfile_store` Patrick Steinhardt
2025-08-20 6:24 ` Junio C Hamano
2025-08-19 8:19 ` [PATCH 04/16] odb: move packfile map " Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 05/16] odb: move MRU list of packfiles " Patrick Steinhardt
2025-08-20 12:44 ` Karthik Nayak
2025-08-20 19:20 ` Jeff King
2025-08-21 6:40 ` Patrick Steinhardt [this message]
2025-08-19 8:19 ` [PATCH 06/16] odb: move kept cache " Patrick Steinhardt
2025-08-19 18:56 ` Junio C Hamano
2025-08-20 4:58 ` Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 07/16] packfile: reorder functions to avoid function declaration Patrick Steinhardt
2025-08-19 19:18 ` Junio C Hamano
2025-08-19 8:19 ` [PATCH 08/16] packfile: refactor `prepare_packed_git()` to work on packfile store Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 09/16] packfile: split up responsibilities of `reprepare_packed_git()` Patrick Steinhardt
2025-08-20 13:17 ` Karthik Nayak
2025-08-19 8:19 ` [PATCH 10/16] packfile: refactor `install_packed_git()` to work on packfile store Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 11/16] packfile: always add packfiles to MRU when adding a pack Patrick Steinhardt
2025-08-20 13:35 ` Karthik Nayak
2025-08-19 8:19 ` [PATCH 12/16] packfile: introduce function to load and add packfiles Patrick Steinhardt
2025-08-20 13:41 ` Karthik Nayak
2025-08-21 6:40 ` Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 13/16] packfile: move `get_multi_pack_index()` into "midx.c" Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 14/16] packfile: remove `get_packed_git()` Patrick Steinhardt
2025-08-20 13:50 ` Karthik Nayak
2025-08-21 6:40 ` Patrick Steinhardt
2025-08-20 13:51 ` Karthik Nayak
2025-08-19 8:19 ` [PATCH 15/16] packfile: refactor `get_all_packs()` to work on packfile store Patrick Steinhardt
2025-08-20 13:53 ` Karthik Nayak
2025-08-21 6:40 ` Patrick Steinhardt
2025-08-19 8:19 ` [PATCH 16/16] packfile: refactor `get_packed_git_mru()` " Patrick Steinhardt
2025-08-19 17:13 ` [PATCH 00/16] packfile: carve out a new " Junio C Hamano
2025-08-20 13:55 ` Karthik Nayak
2025-08-21 7:38 ` [PATCH v2 " Patrick Steinhardt
2025-08-21 7:38 ` [PATCH v2 01/16] packfile: introduce a new `struct packfile_store` Patrick Steinhardt
2025-08-21 7:39 ` [PATCH v2 02/16] odb: move list of packfiles into " Patrick Steinhardt
2025-08-25 23:42 ` Taylor Blau
2025-09-02 8:50 ` Patrick Steinhardt
2025-09-02 17:21 ` Taylor Blau
2025-09-02 17:42 ` Junio C Hamano
2025-09-03 5:58 ` Patrick Steinhardt
2025-09-11 23:16 ` Taylor Blau
2025-09-15 7:44 ` Patrick Steinhardt
2025-08-21 7:39 ` [PATCH v2 03/16] odb: move initialization bit " Patrick Steinhardt
2025-08-26 1:40 ` Taylor Blau
2025-08-21 7:39 ` [PATCH v2 04/16] odb: move packfile map " Patrick Steinhardt
2025-08-26 1:41 ` Taylor Blau
2025-08-21 7:39 ` [PATCH v2 05/16] odb: move MRU list of packfiles " Patrick Steinhardt
2025-08-21 7:39 ` [PATCH v2 06/16] odb: move kept cache " Patrick Steinhardt
2025-08-26 1:46 ` Taylor Blau
2025-09-02 8:50 ` Patrick Steinhardt
2025-08-21 7:39 ` [PATCH v2 07/16] packfile: reorder functions to avoid function declaration Patrick Steinhardt
2025-08-26 1:47 ` Taylor Blau
2025-08-21 7:39 ` [PATCH v2 08/16] packfile: refactor `prepare_packed_git()` to work on packfile store Patrick Steinhardt
2025-08-26 1:58 ` Taylor Blau
2025-08-21 7:39 ` [PATCH v2 09/16] packfile: split up responsibilities of `reprepare_packed_git()` Patrick Steinhardt
2025-08-26 2:10 ` Taylor Blau
2025-09-02 8:50 ` Patrick Steinhardt
2025-08-21 7:39 ` [PATCH v2 10/16] packfile: refactor `install_packed_git()` to work on packfile store Patrick Steinhardt
2025-08-26 2:11 ` Taylor Blau
2025-09-02 8:50 ` Patrick Steinhardt
2025-08-21 7:39 ` [PATCH v2 11/16] packfile: always add packfiles to MRU when adding a pack Patrick Steinhardt
2025-08-27 1:04 ` Taylor Blau
2025-09-02 8:50 ` Patrick Steinhardt
2025-08-21 7:39 ` [PATCH v2 12/16] packfile: introduce function to load and add packfiles Patrick Steinhardt
2025-08-27 1:12 ` Taylor Blau
2025-08-21 7:39 ` [PATCH v2 13/16] packfile: move `get_multi_pack_index()` into "midx.c" Patrick Steinhardt
2025-08-27 1:20 ` Taylor Blau
2025-08-21 7:39 ` [PATCH v2 14/16] packfile: remove `get_packed_git()` Patrick Steinhardt
2025-08-27 1:38 ` Taylor Blau
2025-09-02 8:50 ` Patrick Steinhardt
2025-09-11 23:25 ` Taylor Blau
2025-09-15 7:30 ` Patrick Steinhardt
2025-08-21 7:39 ` [PATCH v2 15/16] packfile: refactor `get_all_packs()` to work on packfile store Patrick Steinhardt
2025-08-27 1:45 ` Taylor Blau
2025-09-02 8:51 ` Patrick Steinhardt
2025-09-11 23:33 ` Taylor Blau
2025-09-15 7:44 ` Patrick Steinhardt
2025-08-21 7:39 ` [PATCH v2 16/16] packfile: refactor `get_packed_git_mru()` " Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 00/15] packfile: carve out a new " Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 01/15] packfile: introduce a new `struct packfile_store` Patrick Steinhardt
2025-09-09 7:49 ` Karthik Nayak
2025-09-02 10:48 ` [PATCH v3 02/15] odb: move list of packfiles into " Patrick Steinhardt
2025-09-09 8:00 ` Karthik Nayak
2025-09-09 11:09 ` Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 03/15] odb: move initialization bit " Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 04/15] odb: move packfile map " Patrick Steinhardt
2025-09-09 8:22 ` Karthik Nayak
2025-09-09 11:01 ` Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 05/15] odb: move MRU list of packfiles " Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 06/15] odb: move kept cache " Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 07/15] packfile: reorder functions to avoid function declaration Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 08/15] packfile: refactor `prepare_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 09/15] packfile: split up responsibilities of `reprepare_packed_git()` Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 10/15] packfile: refactor `install_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 11/15] packfile: introduce function to load and add packfiles Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 12/15] packfile: move `get_multi_pack_index()` into "midx.c" Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 13/15] packfile: remove `get_packed_git()` Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 14/15] packfile: refactor `get_all_packs()` to work on packfile store Patrick Steinhardt
2025-09-02 10:48 ` [PATCH v3 15/15] packfile: refactor `get_packed_git_mru()` " Patrick Steinhardt
2025-09-02 16:40 ` [PATCH v3 00/15] packfile: carve out a new " Junio C Hamano
2025-09-11 23:34 ` Taylor Blau
2025-09-09 9:33 ` Karthik Nayak
2025-09-09 11:02 ` [PATCH v4 " Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 01/15] packfile: introduce a new `struct packfile_store` Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 02/15] odb: move list of packfiles into " Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 03/15] odb: move initialization bit " Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 04/15] odb: move packfile map " Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 05/15] odb: move MRU list of packfiles " Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 06/15] odb: move kept cache " Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 07/15] packfile: reorder functions to avoid function declaration Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 08/15] packfile: refactor `prepare_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 09/15] packfile: split up responsibilities of `reprepare_packed_git()` Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 10/15] packfile: refactor `install_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 11/15] packfile: introduce function to load and add packfiles Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 12/15] packfile: move `get_multi_pack_index()` into "midx.c" Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 13/15] packfile: remove `get_packed_git()` Patrick Steinhardt
2025-09-11 23:37 ` Taylor Blau
2025-09-09 11:03 ` [PATCH v4 14/15] packfile: refactor `get_all_packs()` to work on packfile store Patrick Steinhardt
2025-09-09 11:03 ` [PATCH v4 15/15] packfile: refactor `get_packed_git_mru()` " Patrick Steinhardt
2025-09-10 7:35 ` [PATCH v4 00/15] packfile: carve out a new " Karthik Nayak
2025-09-11 23:40 ` Taylor Blau
2025-09-11 23:42 ` Taylor Blau
2025-09-15 7:25 ` Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 " Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 01/15] packfile: introduce a new `struct packfile_store` Patrick Steinhardt
2025-09-17 21:26 ` Justin Tobler
2025-09-23 9:34 ` Patrick Steinhardt
2025-09-24 21:56 ` Justin Tobler
2025-09-15 8:54 ` [PATCH v5 02/15] odb: move list of packfiles into " Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 03/15] odb: move initialization bit " Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 04/15] odb: move packfile map " Patrick Steinhardt
2025-09-17 22:15 ` Justin Tobler
2025-09-23 9:35 ` Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 05/15] odb: move MRU list of packfiles " Patrick Steinhardt
2025-09-17 21:59 ` Justin Tobler
2025-09-15 8:54 ` [PATCH v5 06/15] odb: move kept cache " Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 07/15] packfile: reorder functions to avoid function declaration Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 08/15] packfile: refactor `prepare_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 09/15] packfile: split up responsibilities of `reprepare_packed_git()` Patrick Steinhardt
2025-09-17 22:32 ` Justin Tobler
2025-09-23 9:34 ` Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 10/15] packfile: refactor `install_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 11/15] packfile: introduce function to load and add packfiles Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 12/15] packfile: move `get_multi_pack_index()` into "midx.c" Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 13/15] packfile: refactor `get_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 14/15] packfile: refactor `get_all_packs()` " Patrick Steinhardt
2025-09-15 8:54 ` [PATCH v5 15/15] packfile: refactor `get_packed_git_mru()` " Patrick Steinhardt
2025-09-23 10:16 ` [PATCH v6 00/15] packfile: carve out a new " Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 01/15] packfile: introduce a new `struct packfile_store` Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 02/15] odb: move list of packfiles into " Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 03/15] odb: move initialization bit " Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 04/15] odb: move packfile map " Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 05/15] odb: move MRU list of packfiles " Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 06/15] odb: move kept cache " Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 07/15] packfile: reorder functions to avoid function declaration Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 08/15] packfile: refactor `prepare_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 09/15] packfile: split up responsibilities of `reprepare_packed_git()` Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 10/15] packfile: refactor `install_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 11/15] packfile: introduce function to load and add packfiles Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 12/15] packfile: move `get_multi_pack_index()` into "midx.c" Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 13/15] packfile: refactor `get_packed_git()` to work on packfile store Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 14/15] packfile: refactor `get_all_packs()` " Patrick Steinhardt
2025-09-23 10:17 ` [PATCH v6 15/15] packfile: refactor `get_packed_git_mru()` " Patrick Steinhardt
2025-09-24 21:58 ` [PATCH v6 00/15] packfile: carve out a new " Justin Tobler
2025-09-25 16:08 ` Junio C Hamano
2025-09-26 5:26 ` Patrick Steinhardt
2025-09-28 22:05 ` Taylor Blau
2025-09-29 21:39 ` Patrick Steinhardt
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