From: Johannes Sixt <j6t@kdbg•org>
To: Patrick Steinhardt <ps@pks•im>
Cc: Matt Smiley <msmiley@gitlab•com>,
"brian m. carlson" <sandals@crustytoothpaste•net>,
Jeff King <peff@peff•net>,
git@vger•kernel.org
Subject: Re: [PATCH v3 00/10] upload-pack: reduce lock contention when writing packfile data
Date: Tue, 10 Mar 2026 21:56:14 +0100 [thread overview]
Message-ID: <2116166d-1aa2-46e5-b912-6268ebbcad4f@kdbg.org> (raw)
In-Reply-To: <20260310-pks-upload-pack-write-contention-v3-0-8bc97aa3e267@pks.im>
Am 10.03.26 um 14:24 schrieb Patrick Steinhardt:
> compat/posix: introduce writev(3p) wrapper
> wrapper: introduce writev(3p) wrappers
I looked at these two patches.
At first, I was thrown off by the early exits when bytes_written == 0.
But I convinced myself that it makes sense:
- In the emulation, if the underlying write(2) does return 0, it makes
sense to signal a partial successful write to the caller of writev. It's
the best we can do when earlier blocks have already been written. A
return value of 0 is strange and may be an indication of future
problems, so let's just stop the work we are doing and let the upper
layers deal with the problem.
- In writev_in_full we need to treat the case specially in order to
guarantee forward progress. Treating it as ENOSPC is plucked out of
thin air, I guess, but not unreasonable.
In conclusion, these patches look good.
-- Hannes
next prev parent reply other threads:[~2026-03-10 20:56 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-27 11:22 [PATCH 0/2] upload-pack: reduce lock contention when writing packfile data Patrick Steinhardt
2026-02-27 11:23 ` [PATCH 1/2] upload-pack: fix debug statement when flushing " Patrick Steinhardt
2026-02-27 11:23 ` [PATCH 2/2] upload-pack: reduce lock contention when writing " Patrick Steinhardt
2026-02-27 13:04 ` brian m. carlson
2026-02-27 18:14 ` Patrick Steinhardt
2026-02-27 17:29 ` Junio C Hamano
2026-02-27 19:37 ` Jeff King
2026-03-02 12:12 ` Patrick Steinhardt
2026-03-02 18:20 ` Jeff King
2026-03-03 9:31 ` Patrick Steinhardt
2026-03-03 13:35 ` Jeff King
2026-03-03 13:47 ` Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 00/10] " Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 01/10] upload-pack: fix debug statement when flushing " Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 02/10] upload-pack: adapt keepalives based on buffering Patrick Steinhardt
2026-03-05 0:56 ` Jeff King
2026-03-10 12:08 ` Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 03/10] upload-pack: reduce lock contention when writing packfile data Patrick Steinhardt
2026-03-05 1:16 ` Jeff King
2026-03-10 12:14 ` Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 04/10] git-compat-util: introduce `cast_size_t_to_ssize_t()` Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 05/10] compat/posix: introduce writev(3p) wrapper Patrick Steinhardt
2026-03-04 22:01 ` Junio C Hamano
2026-03-05 0:37 ` Jeff King
2026-03-05 2:16 ` brian m. carlson
2026-03-05 6:39 ` Johannes Sixt
2026-03-05 22:22 ` brian m. carlson
2026-03-10 12:09 ` Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 06/10] wrapper: introduce writev(3p) wrappers Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 07/10] sideband: use writev(3p) to send pktlines Patrick Steinhardt
2026-03-04 22:05 ` Junio C Hamano
2026-03-03 15:00 ` [PATCH v2 08/10] csum-file: introduce `hashfd_ext()` Patrick Steinhardt
2026-03-04 22:11 ` Junio C Hamano
2026-03-10 12:09 ` Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 09/10] csum-file: drop `hashfd_throughput()` Patrick Steinhardt
2026-03-03 15:00 ` [PATCH v2 10/10] builtin/pack-objects: reduce lock contention when writing packfile data Patrick Steinhardt
2026-03-10 13:24 ` [PATCH v3 00/10] upload-pack: " Patrick Steinhardt
2026-03-10 13:24 ` [PATCH v3 01/10] upload-pack: fix debug statement when flushing " Patrick Steinhardt
2026-03-10 13:24 ` [PATCH v3 02/10] upload-pack: adapt keepalives based on buffering Patrick Steinhardt
2026-03-10 13:24 ` [PATCH v3 03/10] upload-pack: prefer flushing data over sending keepalive Patrick Steinhardt
2026-03-10 17:09 ` Junio C Hamano
2026-03-10 17:43 ` Patrick Steinhardt
2026-03-10 13:25 ` [PATCH v3 04/10] upload-pack: reduce lock contention when writing packfile data Patrick Steinhardt
2026-03-10 13:25 ` [PATCH v3 05/10] compat/posix: introduce writev(3p) wrapper Patrick Steinhardt
2026-03-10 16:59 ` Junio C Hamano
2026-03-10 13:25 ` [PATCH v3 06/10] wrapper: introduce writev(3p) wrappers Patrick Steinhardt
2026-03-10 13:25 ` [PATCH v3 07/10] sideband: use writev(3p) to send pktlines Patrick Steinhardt
2026-03-10 13:25 ` [PATCH v3 08/10] csum-file: introduce `hashfd_ext()` Patrick Steinhardt
2026-03-10 13:25 ` [PATCH v3 09/10] csum-file: drop `hashfd_throughput()` Patrick Steinhardt
2026-03-10 13:25 ` [PATCH v3 10/10] builtin/pack-objects: reduce lock contention when writing packfile data Patrick Steinhardt
2026-03-10 17:11 ` [PATCH v3 00/10] upload-pack: " Junio C Hamano
2026-03-10 20:56 ` Johannes Sixt [this message]
2026-03-11 6:27 ` Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 " Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 01/10] upload-pack: fix debug statement when flushing " Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 02/10] upload-pack: adapt keepalives based on buffering Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 03/10] upload-pack: prefer flushing data over sending keepalive Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 04/10] upload-pack: reduce lock contention when writing packfile data Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 05/10] compat/posix: introduce writev(3p) wrapper Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 06/10] wrapper: introduce writev(3p) wrappers Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 07/10] sideband: use writev(3p) to send pktlines Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 08/10] csum-file: introduce `hashfd_ext()` Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 09/10] csum-file: drop `hashfd_throughput()` Patrick Steinhardt
2026-03-13 6:45 ` [PATCH v4 10/10] builtin/pack-objects: reduce lock contention when writing packfile data Patrick Steinhardt
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