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From: "SZEDER Gábor" <szeder.dev@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: "D. Ben Knoble" <ben.knoble@gmail.com>,
	git@vger.kernel.org, Tian Yuchen <cat@malon.dev>,
	Todd Zullinger <tmz@pobox.com>, Patrick Steinhardt <ps@pks.im>,
	Olamide Caleb Bello <belkid98@gmail.com>
Subject: Re: [PATCH 3/3] core: convert build-time USE_NSEC into runtime core.useNanosec
Date: Sat, 8 Aug 2026 18:31:21 +0200	[thread overview]
Message-ID: <andZ2eIe6RXifor4@szeder.dev> (raw)
In-Reply-To: <xmqqv79ld40c.fsf@gitster.g>

On Fri, Aug 07, 2026 at 02:17:39PM -0700, Junio C Hamano wrote:
> "D. Ben Knoble" <ben.knoble@gmail.com> writes:
> 
> > Racy Git problems persist today, manifesting themselves in the
> > performance of commands like "git diff" in new worktrees [1]. We have
> > long had a build knob "USE_NSEC" to tell Git to use in-core nanosecond
> > precision when available, which mitigates most if not all racy issues,
> > but most builds we know about it don't use it. In part, that's because
> > someone distributing Git can't safely enable it at compile-time if they
> > don't know exactly what platforms their distribution will be used on.
> >
> > [1]: https://lore.kernel.org/git/CALnO6CADMJSixqYvL1Yo8qKX5rWhKQ+2OoSEuPUh-yoeK9TseQ@mail.gmail.com
> >
> > These days, most platforms are likely to be safe for the USE_NSEC code.
> > Regardless, we want to give users the ability to benefit from it. This
> > requires exposing the compile-time gated code as a runtime option.
> >
> > In addition, update the Racy Git documentation and other mentions of
> > USE_NSEC in the code.
> >
> > Best-viewed-with: --ignore-space-change
> 
> Don't do this.  It probably is helpful to have something like that
> below the three-dash lines, though.

Including this hint in the commit message could be useful for anyone
who stumbles upon this commit in a couple of months or years time.
Whether it should be a trailer or not is another question.


      reply	other threads:[~2026-08-08 16:31 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-07 11:56 [PATCH 0/3] Convert USE_NSEC to runtime config D. Ben Knoble
2026-08-07 11:56 ` [PATCH 1/3] meson: expose knob for xmlto relative links in manuals D. Ben Knoble
2026-08-07 11:56 ` [PATCH 2/3] environment: align repo_config_values_init with struct declaration D. Ben Knoble
2026-08-07 11:56 ` [PATCH 3/3] core: convert build-time USE_NSEC into runtime core.useNanosec D. Ben Knoble
2026-08-07 21:17   ` Junio C Hamano
2026-08-08 16:31     ` SZEDER Gábor [this message]

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