From: Linus Torvalds <torvalds@linux-foundation.org>
To: George Spelvin <linux@horizon.com>
Cc: git@vger.kernel.org
Subject: Re: Git commit generation numbers
Date: Sun, 17 Jul 2011 16:58:59 -0700 [thread overview]
Message-ID: <CA+55aFwt+RDRK_r=9CXbdzsLuGDqswvGTtJDKi9Q3DQwB_Ha5Q@mail.gmail.com> (raw)
In-Reply-To: <20110717233959.3548.qmail@science.horizon.com>
On Sun, Jul 17, 2011 at 4:39 PM, George Spelvin <linux@horizon.com> wrote:
>
> I'm slapping my forehead like Homer Simpson here. The fact that computing
> the generation number is expensive is why it's worth cacheing. But the
> fact that it *can* be computed is a reason not to clutter the published
> commit object format with it.
And I'm slapping *my* forehead.
Nobody has *ever* given a reason why the cache would be better than
just making it explicit.
That's my issue.
Why is that so hard for people to understand? The cache is just EXTRA WORK.
To take your TLB example: it's like having a TLB for a page table that
would be as easy to just create in a way that it's *faster* to look up
in the actual data structure than it would be to look up in the cache.
Or to take your disk cache example: wouldn't you say that a disk cache
is a F&*&ING BAD IDEA if it is slower than the disk it caches?
Seriously.
Linus
next prev parent reply other threads:[~2011-07-17 23:59 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-17 18:27 Git commit generation numbers George Spelvin
2011-07-17 19:00 ` Long, Martin
2011-07-17 19:30 ` Linus Torvalds
2011-07-17 23:39 ` George Spelvin
2011-07-17 23:58 ` Linus Torvalds [this message]
2011-07-18 5:13 ` George Spelvin
2011-07-18 10:28 ` Anthony Van de Gejuchte
2011-07-18 11:48 ` George Spelvin
2011-07-20 20:51 ` Nicolas Pitre
2011-07-20 22:16 ` George Spelvin
2011-07-20 23:26 ` david
2011-07-20 23:36 ` Nicolas Pitre
2011-07-21 0:08 ` Phil Hord
2011-07-21 0:18 ` david
2011-07-21 0:37 ` Shawn Pearce
2011-07-21 0:47 ` Phil Hord
2011-07-21 4:26 ` david
2011-07-21 12:43 ` George Spelvin
2011-07-21 19:19 ` Jakub Narebski
2011-07-21 20:27 ` George Spelvin
2011-07-21 20:33 ` Shawn Pearce
2011-07-22 12:18 ` Jakub Narebski
2011-07-22 13:09 ` Nicolas Pitre
2011-07-22 18:02 ` david
2011-07-22 18:34 ` Jakub Narebski
2011-07-22 19:06 ` Linus Torvalds
2011-07-22 22:02 ` Jeff King
2011-07-28 15:00 ` Felipe Contreras
2011-09-06 10:02 ` Ramkumar Ramachandra
2011-07-22 19:08 ` david
2011-07-22 19:40 ` Nicolas Pitre
2011-07-22 18:02 ` david
2011-07-21 0:39 ` Phil Hord
2011-07-21 0:58 ` Nicolas Pitre
2011-07-21 1:09 ` Phil Hord
2011-07-21 12:03 ` Drew Northup
2011-07-21 12:55 ` George Spelvin
2011-07-21 15:57 ` Drew Northup
2011-07-21 16:24 ` Phil Hord
2011-07-21 22:40 ` Pēteris Kļaviņš
2011-07-22 9:30 ` Christian Couder
2011-07-21 17:36 ` George Spelvin
-- strict thread matches above, loose matches on Subject: below --
2011-07-14 18:24 Linus Torvalds
2011-07-14 18:37 ` Jeff King
2011-07-14 18:47 ` Linus Torvalds
2011-07-14 18:55 ` Linus Torvalds
2011-07-14 19:12 ` Jeff King
2011-07-14 19:46 ` Ted Ts'o
2011-07-14 19:51 ` Linus Torvalds
2011-07-14 20:07 ` Jeff King
2011-07-14 20:08 ` Ted Ts'o
2011-07-14 19:08 ` Jeff King
2011-07-14 19:23 ` Linus Torvalds
2011-07-14 20:01 ` Jeff King
2011-07-14 20:19 ` Linus Torvalds
2011-07-14 20:31 ` Jeff King
2011-07-15 1:19 ` Linus Torvalds
2011-07-15 2:41 ` Geert Bosch
2011-07-15 7:46 ` Jeff King
2011-07-15 16:10 ` Linus Torvalds
2011-07-15 16:18 ` Shawn Pearce
2011-07-15 16:44 ` Linus Torvalds
2011-07-15 18:42 ` Ted Ts'o
2011-07-15 19:00 ` Linus Torvalds
2011-07-16 9:16 ` Christian Couder
2011-07-18 3:41 ` Jeff King
2011-07-19 4:14 ` Christian Couder
2011-07-19 20:00 ` Jeff King
2011-07-21 6:29 ` Christian Couder
2011-07-15 18:46 ` Tony Luck
2011-07-15 18:58 ` Linus Torvalds
2011-07-15 19:48 ` Jeff King
2011-07-15 20:07 ` Jeff King
2011-07-15 21:17 ` Linus Torvalds
2011-07-15 21:54 ` Jeff King
2011-07-15 23:10 ` Linus Torvalds
2011-07-15 23:16 ` Linus Torvalds
2011-07-15 23:36 ` Linus Torvalds
2011-07-16 0:42 ` Jeff King
2011-07-16 0:40 ` Jeff King
2011-07-15 9:12 ` Jakub Narebski
2011-07-15 9:17 ` Long, Martin
2011-07-15 15:33 ` Long, Martin
2011-07-15 16:15 ` Drew Northup
2011-07-14 18:52 ` Linus Torvalds
2011-07-14 19:08 ` Jakub Narebski
2011-07-14 20:26 ` Junio C Hamano
2011-07-14 20:41 ` Jeff King
2011-07-14 21:30 ` Junio C Hamano
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