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From: Jeff King <peff@peff.net>
To: Taylor Blau <me@ttaylorr.com>
Cc: git@vger.kernel.org, gitster@pobox.com, pclouds@gmail.com
Subject: Re: [PATCH] pack-objects.h: remove outdated pahole results
Date: Fri, 1 Jul 2022 17:05:19 -0400	[thread overview]
Message-ID: <Yr9hj19gmoiArVat@coredump.intra.peff.net> (raw)
In-Reply-To: <Yr9Pg9mRQWe1tgE+@nand.local>

On Fri, Jul 01, 2022 at 03:48:19PM -0400, Taylor Blau wrote:

> > I agree the actual numbers aren't helping anybody. We _could_ leave a
> > comment that says "we store a lot of these in memory; be careful of
> > where and how you add new fields to avoid increasing the struct size".
> > And then people can run "pahole" before and after their changes.
> >
> > But then that is also true of other structs (like "struct object"), and
> > we do not bother there. So it probably is fine not to annotate this
> > specifically.
> 
> We have such a comment at the very type of the block comment above
> `struct object_entry`'s definition:
> 
>     "The size of struct nearly determines pack-object's memory
>     consumption. This struct is packed tight for that reason. When you
>     add or reorder something in this struct, think a bit about this".
> 
> thanks to Duy back in 3b13a5f263 (pack-objects: reorder members to
> shrink struct object_entry, 2018-04-14).

Oh, indeed. Then I withdraw my (non-)complaint. :)

-Peff

      reply	other threads:[~2022-07-01 21:05 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-28 18:30 [PATCH] pack-objects.h: remove outdated pahole results Taylor Blau
2022-06-28 20:03 ` Derrick Stolee
2022-06-28 21:04 ` brian m. carlson
2022-06-28 21:26   ` Taylor Blau
2022-07-01 18:16 ` Jeff King
2022-07-01 19:48   ` Taylor Blau
2022-07-01 21:05     ` Jeff King [this message]

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